Agricultural and Biological Sciences › Plant Science

Plant-Microbe Interactions and Immunity

Works Count: 52186

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Description

This cluster of papers explores the mechanisms of plant immune response, including the role of root exudates, rhizosphere interactions with beneficial and pathogenic microorganisms, systemic acquired resistance, and the impact of plant growth-promoting bacteria. It delves into the signaling pathways, defense mechanisms, and hormonal modulation involved in plant immunity against microbial pathogens.

Keywords

Plant Immunity; Rhizosphere Interactions; Microbial Pathogens; Pattern Recognition Receptors; Systemic Acquired Resistance; Plant Growth-Promoting Bacteria; Hormonal Modulation; Root Exudates; Pathogen Defense; Microbiome

Plant species and soil type cooperatively shape the structure and function of microbial communities in the rhizosphere

2009-02-25

Gabriele Berg , Kornelia Smalla

The rhizosphere is of central importance not only for plant nutrition, health and quality but also for microorganism-driven carbon sequestration, ecosystem functioning and nutrient cycling in terrestrial ecosystems. A multitude … The rhizosphere is of central importance not only for plant nutrition, health and quality but also for microorganism-driven carbon sequestration, ecosystem functioning and nutrient cycling in terrestrial ecosystems. A multitude of biotic and abiotic factors are assumed to influence the structural and functional diversity of microbial communities in the rhizosphere. In this review, recent studies on the influence of the two factors, plant species and soil type, on rhizosphere-associated microbial communities are discussed. Root exudates and the response of microorganisms to the latter as well as to root morphology were shown to shape rhizosphere microbial communities. All studies revealed that soil is the main reservoir for rhizosphere microorganisms. Many secrets of microbial life in the rhizosphere were recently uncovered due to the enormous progress in molecular and microscopic tools. Physiological and molecular data on the factors that drive selection processes in the rhizosphere are presented here. Furthermore, implications for agriculture, nature conservation and biotechnology will also be discussed.

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Rhizosphere bacteria help plants tolerate abiotic stress

2008-12-05

Yang Jung-Wook , Joseph W. Kloepper , Choong‐Min Ryu

Role of Pseudomonas putida Indoleacetic Acid in Development of the Host Plant Root System

2002-08-01

Cheryl L. Patten , Bernard R. Glick

ABSTRACT Many plant-associated bacteria synthesize the phytohormone indoleacetic acid (IAA). While IAA produced by phytopathogenic bacteria, mainly by the indoleacetamide pathway, has been implicated in the induction of plant tumors, … ABSTRACT Many plant-associated bacteria synthesize the phytohormone indoleacetic acid (IAA). While IAA produced by phytopathogenic bacteria, mainly by the indoleacetamide pathway, has been implicated in the induction of plant tumors, it is not clear whether IAA synthesized by beneficial bacteria, usually via the indolepyruvic acid pathway, is involved in plant growth promotion. To determine whether bacterial IAA enhances root development in host plants, the ipdc gene that encodes indolepyruvate decarboxylase, a key enzyme in the indolepyruvic acid pathway, was isolated from the plant growth-promoting bacterium Pseudomonas putida GR12-2 and an IAA-deficient mutant constructed by insertional mutagenesis. The canola seedling primary roots from seeds treated with wild-type P. putida GR12-2 were on average 35 to 50% longer than the roots from seeds treated with the IAA-deficient mutant and the roots from uninoculated seeds. In addition, exposing mung bean cuttings to high levels of IAA by soaking them in a suspension of the wild-type strain stimulated the formation of many, very small, adventitious roots. Formation of fewer roots was stimulated by treatment with the IAA-deficient mutant. These results suggest that bacterial IAA plays a major role in the development of the host plant root system.

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Plant pathogens and integrated defence responses to infection

2001-06-14

Jeffery L. Dangl , Jonathan D. G. Jones

Defining the core Arabidopsis thaliana root microbiome

2012-07-31

Derek S. Lundberg , Sarah L. Lebeis , Sur Herrera Paredes +7 more

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A Central Role of Salicylic Acid in Plant Disease Resistance

1994-11-18

Terrence P. Delaney , Scott Uknes , Bernard Vernooij +7 more

Transgenic tobacco and Arabidopsis thaliana expressing the bacterial enzyme salicylate hydroxylase cannot accumulate salicylic acid (SA). This defect not only makes the plants unable to induce systemic acquired resistance, but … Transgenic tobacco and Arabidopsis thaliana expressing the bacterial enzyme salicylate hydroxylase cannot accumulate salicylic acid (SA). This defect not only makes the plants unable to induce systemic acquired resistance, but also leads to increased susceptibility to viral, fungal, and bacterial pathogens. The enhanced susceptibility extends even to host-pathogen combinations that would normally result in genetic resistance. Therefore, SA accumulation is essential for expression of multiple modes of plant disease resistance.

Improved method for the isolation of RNA from plant tissues

1987-05-01

J. Logemann , Jeff Schell , Lothar Willmitzer

Perception of the Bacterial PAMP EF-Tu by the Receptor EFR Restricts Agrobacterium-Mediated Transformation

2006-05-01

Cyril Zipfel , Gernot Kunze , Delphine Chinchilla +4 more

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A flagellin-induced complex of the receptor FLS2 and BAK1 initiates plant defence

2007-07-01

Delphine Chinchilla , Cyril Zipfel , Silke Robatzek +5 more

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Isochorismate synthase is required to synthesize salicylic acid for plant defence

2001-11-29

Mary C. Wildermuth , Julia Dewdney , Gang Wu +1 more

Plant Stomata Function in Innate Immunity against Bacterial Invasion

2006-09-01

Maeli Melotto , William Underwood , Jessica M. Koczan +2 more

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Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

2013-05-11

Munees Ahemad , Mulugeta Kibret

Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of … Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally, plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in resource acquisition (nitrogen, phosphorus and essential minerals) or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria under both normal and stressed conditions. The plant-beneficial rhizobacteria may decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems. This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria under the current perspectives. Further, explicit outlooks on the different mechanisms of rhizobacteria mediated plant growth promotion have been described in detail with the recent development and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria in different agro-ecosystems have been presented comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insights.

Plant immunity: towards an integrated view of plant–pathogen interactions

2010-06-29

Peter N. Dodds , John P. Rathjen

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Plant Growth-Promoting Bacteria: Mechanisms and Applications

2012-01-01

Bernard R. Glick

The worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. … The worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. It is therefore essential that agricultural productivity be significantly increased within the next few decades. To this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. This includes both the increasing use of transgenic plants and plant growth-promoting bacteria as a part of mainstream agricultural practice. Here, a number of the mechanisms utilized by plant growth-promoting bacteria are discussed and considered. It is envisioned that in the not too distant future, plant growth-promoting bacteria (PGPB) will begin to replace the use of chemicals in agriculture, horticulture, silviculture, and environmental cleanup strategies. While there may not be one simple strategy that can effectively promote the growth of all plants under all conditions, some of the strategies that are discussed already show great promise.

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The rhizosphere microbiome and plant health

2012-05-06

Roeland L. Berendsen , Corné M. J. Pieterse , Peter A. H. M. Bakker

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Deciphering the Rhizosphere Microbiome for Disease-Suppressive Bacteria

2011-05-06

Rodrigo Mendes , M. Kruijt , Irene de Bruijn +7 more

A common plant pathogen induces the growth of disease-suppressive microbes in local soil communities. A common plant pathogen induces the growth of disease-suppressive microbes in local soil communities.

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Plant growth-promoting bacteria in the rhizo- and endosphere of plants: Their role, colonization, mechanisms involved and prospects for utilization

2009-12-10

Stéphane Compant , Christophe Clément , Angela Sessitsch

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Microbial life in the phyllosphere

2012-11-16

Julia A. Vorholt

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Host-Microbe Interactions: Shaping the Evolution of the Plant Immune Response

2006-02-01

Stephen T. Chisholm , Gitta Coaker , Brad Day +1 more

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The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms

2013-06-24

Rodrigo Mendes , Paolina Garbeva , Jos M. Raaijmakers

Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also … Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protective microbial shield and to overcome the innate plant defense mechanisms in order to cause disease. A third group of microorganisms that can be found in the rhizosphere are the true and opportunistic human pathogenic bacteria, which can be carried on or in plant tissue and may cause disease when introduced into debilitated humans. Although the importance of the rhizosphere microbiome for plant growth has been widely recognized, for the vast majority of rhizosphere microorganisms no knowledge exists. To enhance plant growth and health, it is essential to know which microorganism is present in the rhizosphere microbiome and what they are doing. Here, we review the main functions of rhizosphere microorganisms and how they impact on health and disease. We discuss the mechanisms involved in the multitrophic interactions and chemical dialogues that occur in the rhizosphere. Finally, we highlight several strategies to redirect or reshape the rhizosphere microbiome in favor of microorganisms that are beneficial to plant growth and health.

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Arabidopsis mesophyll protoplasts: a versatile cell system for transient gene expression analysis

2007-06-21

Sang-Dong Yoo , Young-Hee Cho , Jen Sheen

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Indole-3-acetic acid in microbial and microorganism-plant signaling

2007-05-18

Stijn Spaepen , Jos Vanderleyden , Roseline Remans

Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and redundancy for IAA biosynthesis is widespread among plant-associated bacteria. … Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and redundancy for IAA biosynthesis is widespread among plant-associated bacteria. Interactions between IAA-producing bacteria and plants lead to diverse outcomes on the plant side, varying from pathogenesis to phyto-stimulation. Reviewing the role of bacterial IAA in different microorganism-plant interactions highlights the fact that bacteria use this phytohormone to interact with plants as part of their colonization strategy, including phyto-stimulation and circumvention of basal plant defense mechanisms. Moreover, several recent reports indicate that IAA can also be a signaling molecule in bacteria and therefore can have a direct effect on bacterial physiology. This review discusses past and recent data, and emerging views on IAA, a well-known phytohormone, as a microbial metabolic and signaling molecule.

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H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response

1994-11-01

Alex J. Levine , Raimund Tenhaken , Richard A. Dixon +1 more

The Aerobic Pseudomonads a Taxonomic Study

1966-05-01

Roger Y. Stanier , Norberto J. Palleroni , Michael Doudoroff

SUMMARY A collection of 267 strains, representing many of the principal biotypes among aerobic pseudomonads, has been subjected to detailed study, with particular emphasis on biochemical, physiological and nutritional characters. … SUMMARY A collection of 267 strains, representing many of the principal biotypes among aerobic pseudomonads, has been subjected to detailed study, with particular emphasis on biochemical, physiological and nutritional characters. A total of 146 different organic compounds were tested for their ability to serve as sources of carbon and energy. Other characters that were studied included : production of extracellular hydrolases; nitrogen sources and growth factor requirements H-chemolithotrophy; denitrifying ability; pigment production; ability to accumulate poly-p-hydroxybutyrate as a cellular reserve material; biochemical mechanisms of aromatic ring cleavage; and nature of the aerobic electron transport system. The resultant data have revealed many hitherto unrecognized characters of taxonomic significance. As a consequence, it has become possible to recognize among the biotypes examined a limited number of species which can be readily and clearly distinguished from one another by multiple, unrelated phenotypic differences.

Biological control of soil-borne pathogens by fluorescent pseudomonads

2005-03-10

Dieter Haas , Geneviève Défago

The importance of the microbiome of the plant holobiont

2015-02-05

Philippe Vandenkoornhuyse , Achim Quaiser , Marie Duhamel +2 more

Plants can no longer be considered as standalone entities and a more holistic perception is needed. Indeed, plants harbor a wide diversity of microorganisms both inside and outside their tissues, … Plants can no longer be considered as standalone entities and a more holistic perception is needed. Indeed, plants harbor a wide diversity of microorganisms both inside and outside their tissues, in the endosphere and ectosphere, respectively. These microorganisms, which mostly belong to Bacteria and Fungi, are involved in major functions such as plant nutrition and plant resistance to biotic and abiotic stresses. Hence, the microbiota impact plant growth and survival, two key components of fitness. Plant fitness is therefore a consequence of the plant per se and its microbiota, which collectively form a holobiont. Complementary to the reductionist perception of evolutionary pressures acting on plant or symbiotic compartments, the plant holobiont concept requires a novel perception of evolution. The interlinkages between the plant holobiont components are explored here in the light of current ecological and evolutionary theories. Microbiome complexity and the rules of microbiotic community assemblage are not yet fully understood. It is suggested that the plant can modulate its microbiota to dynamically adjust to its environment. To better understand the level of plant dependence on the microbiotic components, the core microbiota need to be determined at different hierarchical scales of ecology while pan-microbiome analyses would improve characterization of the functions displayed.

Plant-Growth-Promoting Rhizobacteria

2009-09-08

Ben Lugtenberg , Faina Kamilova

Several microbes promote plant growth, and many microbial products that stimulate plant growth have been marketed. In this review we restrict ourselves to bacteria that are derived from and exert … Several microbes promote plant growth, and many microbial products that stimulate plant growth have been marketed. In this review we restrict ourselves to bacteria that are derived from and exert this effect on the root. Such bacteria are generally designated as PGPR (plant-growth-promoting rhizobacteria). The beneficial effects of these rhizobacteria on plant growth can be direct or indirect. This review begins with describing the conditions under which bacteria live in the rhizosphere. To exert their beneficial effects, bacteria usually must colonize the root surface efficiently. Therefore, bacterial traits required for root colonization are subsequently described. Finally, several mechanisms by which microbes can act beneficially on plant growth are described. Examples of direct plant growth promotion that are discussed include (a) biofertilization, (b) stimulation of root growth, (c) rhizoremediation, and (d) plant stress control. Mechanisms of biological control by which rhizobacteria can promote plant growth indirectly, i.e., by reducing the level of disease, include antibiosis, induction of systemic resistance, and competition for nutrients and niches.

Going back to the roots: the microbial ecology of the rhizosphere

2013-09-23

Laurent Philippot , Jos M. Raaijmakers , Philippe Lemanceau +1 more

Biological Control of Soilborne Plant Pathogens in the Rhizosphere with Bacteria

1988-09-01

David M. Weller

In the last 15 years, several examples of bacteria capable of providing substantial disease control in the field have been reported, and at times control approaches that in suppressive soils.These … In the last 15 years, several examples of bacteria capable of providing substantial disease control in the field have been reported, and at times control approaches that in suppressive soils.These more recent successes in biologi cal control, which are in contrast to less successful attempts early in this century (49), result in part from a greater understanding of the rhizosphere and the selection of strains more adapted to growing there.Bacterial biocon trol agents improve plant growth by suppressing either major or minor pathogens.Major pathogens produce the well-known root or vascular diseases with obvious symptoms (163).Minor pathogens are parasites or saprophytes that damage mainly juvenile tissue such as root hairs and tips and cortical cells (163), and the disease symptoms are not obvious.Within the category of minor pathogens, Schippers et al ( 170) distinguished the parasitizing minor pathogens from the nonparasitizing del eterious rhizosphere microorganisms (DRMO).DRMO include deleterious rhizobacteria (DRB) (184) and deleteri ous fungi.Other discussions of this topic are available (30, 173, 174, 183).This review examines the current successes and problems of biological con trol of soilborne pathogens with bacteria in the rhizosphere.This chapter also discusses possible reasons for inconsistent performance of biocontrol agents in the field and approaches to help realize the full potential of bacteria in plant-disease control.It focuses on the mechanisms by which introduced bacteria suppress pathogens and traits that may contribute to their ability to colonize roots.

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Trichoderma species — opportunistic, avirulent plant symbionts

2004-01-01

Gary E. Harman , Charles R. Howell , Ada Viterbo +2 more

Contrasting Mechanisms of Defense Against Biotrophic and Necrotrophic Pathogens

2005-03-05

Jane Glazebrook

It has been suggested that effective defense against biotrophic pathogens is largely due to programmed cell death in the host, and to associated activation of defense responses regulated by the … It has been suggested that effective defense against biotrophic pathogens is largely due to programmed cell death in the host, and to associated activation of defense responses regulated by the salicylic acid-dependent pathway. In contrast, necrotrophic pathogens benefit from host cell death, so they are not limited by cell death and salicylic acid-dependent defenses, but rather by a different set of defense responses activated by jasmonic acid and ethylene signaling. This review summarizes results from Arabidopsis-pathogen systems regarding the contributions of various defense responses to resistance to several biotrophic and necrotrophic pathogens. While the model above seems generally correct, there are exceptions and additional complexities.

SYSTEMIC ACQUIRED RESISTANCE

2004-07-29

Wendy E. Durrant , Xinnian Dong

Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. SAR requires the signal molecule salicylic acid (SA) and is … Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. SAR requires the signal molecule salicylic acid (SA) and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. Much progress has been made recently in elucidating the mechanism of SAR. Using the model plant Arabidopsis, it was discovered that the isochorismate pathway is the major source of SA during SAR. In response to SA, the positive regulator protein NPR1 moves to the nucleus where it interacts with TGA transcription factors to induce defense gene expression, thus activating SAR. Exciting new data suggest that the mobile signal for SAR might be a lipid molecule. We discuss the molecular and genetic data that have contributed to our understanding of SAR and present a model describing the sequence of events leading from initial infection to the induction of defense genes.

Use of Plant Growth-Promoting Bacteria for Biocontrol of Plant Diseases: Principles, Mechanisms of Action, and Future Prospects

2005-09-01

Stéphane Compant , Brion Duffy , Jerzy Nowak +2 more

Pathogenic microorganisms affecting plant health are a major and chronic threat to food production and ecosystem stability worldwide. As agricultural production intensified over the past few decades, producers became more … Pathogenic microorganisms affecting plant health are a major and chronic threat to food production and ecosystem stability worldwide. As agricultural production intensified over the past few decades, producers became more and more dependent on agrochemicals as a relatively reliable method of crop

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A Renaissance of Elicitors: Perception of Microbe-Associated Molecular Patterns and Danger Signals by Pattern-Recognition Receptors

2009-01-23

Thomas Boller , Georg Felix

Microbe-associated molecular patterns (MAMPs) are molecular signatures typical of whole classes of microbes, and their recognition plays a key role in innate immunity. Endogenous elicitors are similarly recognized as damage-associated … Microbe-associated molecular patterns (MAMPs) are molecular signatures typical of whole classes of microbes, and their recognition plays a key role in innate immunity. Endogenous elicitors are similarly recognized as damage-associated molecular patterns (DAMPs). This review focuses on the diversity of MAMPs/DAMPs and on progress to identify the corresponding pattern recognition receptors (PRRs) in plants. The two best-characterized MAMP/PRR pairs, flagellin/FLS2 and EF-Tu/EFR, are discussed in detail and put into a phylogenetic perspective. Both FLS2 and EFR are leucine-rich repeat receptor kinases (LRR-RKs). Upon treatment with flagellin, FLS2 forms a heteromeric complex with BAK1, an LRR-RK that also acts as coreceptor for the brassinolide receptor BRI1. The importance of MAMP/PRR signaling for plant immunity is highlighted by the finding that plant pathogens use effectors to inhibit PRR complexes or downstream signaling events. Current evidence indicates that MAMPs, DAMPs, and effectors are all perceived as danger signals and induce a stereotypic defense response.

Induced Systemic Resistance by Beneficial Microbes

2014-06-06

Corné M. J. Pieterse , Christos Zamioudis , Roeland L. Berendsen +3 more

Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth-promoting bacteria and fungi in the … Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth-promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of pathogens and insect herbivores. A wide variety of root-associated mutualists, including Pseudomonas, Bacillus, Trichoderma, and mycorrhiza species sensitize the plant immune system for enhanced defense without directly activating costly defenses. This review focuses on molecular processes at the interface between plant roots and ISR-eliciting mutualists, and on the progress in our understanding of ISR signaling and systemic defense priming. The central role of the root-specific transcription factor MYB72 in the onset of ISR and the role of phytohormones and defense regulatory proteins in the expression of ISR in aboveground plant parts are highlighted. Finally, the ecological function of ISR-inducing microbes in the root microbiome is discussed.

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Salicylic Acid, a Multifaceted Hormone to Combat Disease

2009-08-03

A. Corina Vlot , D’Maris Amick Dempsey , Daniel F. Klessig

For more than 200 years, the plant hormone salicylic acid (SA) has been studied for its medicinal use in humans. However, its extensive signaling role in plants, particularly in defense … For more than 200 years, the plant hormone salicylic acid (SA) has been studied for its medicinal use in humans. However, its extensive signaling role in plants, particularly in defense against pathogens, has only become evident during the past 20 years. This review surveys how SA in plants regulates both local disease resistance mechanisms, including host cell death and defense gene expression, and systemic acquired resistance (SAR). Genetic studies reveal an increasingly complex network of proteins required for SA-mediated defense signaling, and this process is amplified by several regulatory feedback loops. The interaction between the SA signaling pathway and those regulated by other plant hormones and/or defense signals is also discussed.

Revealing structure and assembly cues for Arabidopsis root-inhabiting bacterial microbiota

2012-07-31

Davide Bulgarelli , Matthias Rott , Klaus Schlaeppi +7 more

SYSTEMIC RESISTANCE INDUCED BY RHIZOSPHERE BACTERIA

1998-09-01

L.C. van Loon , Peter A. H. M. Bakker , Corné M. J. Pieterse

Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, … Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carnation, cucumber, radish, tobacco, and tomato under conditions in which the inducing bacteria and the challenging pathogen remained spatially separated. Bacterial strains differ in their ability to induce resistance in different plant species, and plants show variation in the expression of ISR upon induction by specific bacterial strains. Bacterial determinants of ISR include lipopolysaccharides, siderophores, and salicylic acid (SA). Whereas some of the rhizobacteria induce resistance through the SA-dependent SAR pathway, others do not and require jasmonic acid and ethylene perception by the plant for ISR to develop. No consistent host plant alterations are associated with the induced state, but upon challenge inoculation, resistance responses are accelerated and enhanced. ISR is effective under field conditions and offers a natural mechanism for biological control of plant disease.

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Microbiology of the Phyllosphere

2003-04-01

Steven E. Lindow , Maria T. Brandl

The above-ground parts of plants are normally colonized by a variety of bacteria, yeasts, and fungi. While a few microbial species can be isolated from within plant tissues, many more … The above-ground parts of plants are normally colonized by a variety of bacteria, yeasts, and fungi. While a few microbial species can be isolated from within plant tissues, many more are recovered from the surfaces of healthy plants. The aerial habitat colonized by these microbes is termed the

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MAP kinase signalling cascade in Arabidopsis innate immunity

2002-02-01

Tsuneaki Asai , Guillaume Tena , Joulia Plotnikova +6 more

Plant growth-promoting rhizobacteria (PGPR): emergence in agriculture

2011-12-23

Pranaba Nanda Bhattacharyya , Dhruva Kumar Jha

Significance of Inducible Defense-related Proteins in Infected Plants

2006-04-07

L.C. van Loon , Martijn Rep , Corné M. J. Pieterse

Inducible defense-related proteins have been described in many plant species upon infection with oomycetes, fungi, bacteria, or viruses, or insect attack. Several types of proteins are common and have been … Inducible defense-related proteins have been described in many plant species upon infection with oomycetes, fungi, bacteria, or viruses, or insect attack. Several types of proteins are common and have been classified into 17 families of pathogenesis-related proteins (PRs). Others have so far been found to occur more specifically in some plant species. Most PRs and related proteins are induced through the action of the signaling compounds salicylic acid, jasmonic acid, or ethylene, and possess antimicrobial activities in vitro through hydrolytic activities on cell walls, contact toxicity, and perhaps an involvement in defense signaling. However, when expressed in transgenic plants, they reduce only a limited number of diseases, depending on the nature of the protein, plant species, and pathogen involved. As exemplified by the PR-1 proteins in Arabidopsis and rice, many homologous proteins belonging to the same family are regulated developmentally and may serve different functions in specific organs or tissues. Several defense-related proteins are induced during senescence, wounding or cold stress, and some possess antifreeze activity. Many defense-related proteins are present constitutively in floral tissues and a substantial number of PR-like proteins in pollen, fruits, and vegetables can provoke allergy in humans. The evolutionary conservation of similar defense-related proteins in monocots and dicots, but also their divergent occurrence in other conditions, suggest that these proteins serve essential functions in plant life, whether in defense or not.

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Current Status of the Gene-For-Gene Concept

1971-09-01

H. H. Flor

Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the … Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for ...Read More

Structure and Functions of the Bacterial Microbiota of Plants

2013-02-02

Davide Bulgarelli , Klaus Schlaeppi , Stijn Spaepen +2 more

Plants host distinct bacterial communities on and inside various plant organs, of which those associated with roots and the leaf surface are best characterized. The phylogenetic composition of these communities … Plants host distinct bacterial communities on and inside various plant organs, of which those associated with roots and the leaf surface are best characterized. The phylogenetic composition of these communities is defined by relatively few bacterial phyla, including Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. A synthesis of available data suggests a two-step selection process by which the bacterial microbiota of roots is differentiated from the surrounding soil biome. Rhizodeposition appears to fuel an initial substrate-driven community shift in the rhizosphere, which converges with host genotype-dependent fine-tuning of microbiota profiles in the selection of root endophyte assemblages. Substrate-driven selection also underlies the establishment of phyllosphere communities but takes place solely at the immediate leaf surface. Both the leaf and root microbiota contain bacteria that provide indirect pathogen protection, but root microbiota members appear to serve additional host functions through the acquisition of nutrients from soil for plant growth. Thus, the plant microbiota emerges as a fundamental trait that includes mutualism enabled through diverse biochemical mechanisms, as revealed by studies on plant growth-promoting and plant health-promoting bacteria.

The plant immune system

2006-11-01

Jonathan D. G. Jones , Jeffery L. Dangl

THE OXIDATIVE BURST IN PLANT DISEASE RESISTANCE

1997-06-01

Chris Lamb , Richard A. Dixon

Rapid generation of superoxide and accumulation of H2O2 is a characteristic early feature of the hypersensitive response following perception of pathogen avirulence signals. Emerging data indicate that the oxidative burst … Rapid generation of superoxide and accumulation of H2O2 is a characteristic early feature of the hypersensitive response following perception of pathogen avirulence signals. Emerging data indicate that the oxidative burst reflects activation of a membrane-bound NADPH oxidase closely resembling that operating in activated neutrophils. The oxidants are not only direct protective agents, but H2O2 also functions as a substrate for oxidative cross-linking in the cell wall, as a threshold trigger for hypersensitive cell death, and as a diffusible signal for induction of cellular protectant genes in surrounding cells. Activation of the oxidative burst is a central component of a highly amplified and integrated signal system, also involving salicylic acid and perturbations of cytosolic Ca2+, which underlies the expression of disease-resistance mechanisms.

Bacillus lipopeptides: versatile weapons for plant disease biocontrol

2008-03-01

Marc Ongena , Philippe Jacques

The families of pathogenesis-related proteins, their activities, and comparative analysis of PR-1 type proteins

1999-08-01

L.C. van Loon , E. A. van Strien

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The its Region of Nuclear Ribosomal DNA: A Valuable Source of Evidence on Angiosperm Phylogeny

1995-01-01

Bruce G. Baldwin , Michael J. Sanderson , J. Mark Porter +3 more

Plant–microbiome interactions: from community assembly to plant health

2020-08-12

Pankaj Trivedi , Jan E. Leach , Susannah G. Tringe +2 more

Engineering synthetic microbial communities to restructure the phytobiome for plant health and productivity

2025-06-25

Anwesha Sharma , Popy Bora | World Journal of Microbiology and Biotechnology

ABP-B9, a new strain of Pseudomonas seleniipraecipitans with biostimulant activity

2025-06-25

Agustina Bernal‐Vicente , Pedro Joaquín Sánchez-Pujante , Pedro Díaz‐Vivancos +3 more | Frontiers in Plant Science

Introduction Microorganisms are emerging as key agents in sustainable agriculture due to their ability to enhance crop productivity while reducing environmental impact. Among them, Pseudomonas spp. are well known for … Introduction Microorganisms are emerging as key agents in sustainable agriculture due to their ability to enhance crop productivity while reducing environmental impact. Among them, Pseudomonas spp. are well known for promoting plant growth through mechanisms such as phytohormone production and improved nutrient availability. This study describes the characterization of the strain ABP-B9, isolated from the rhizosphere of commercial lettuce crops. Materials and methods ABP-B9 was evaluated under both field and controlled conditions to assess its plant growth-promoting effects. Parameters such as root development, photosynthetic efficiency, flavonoid content, nitrogen status, and the production of indole-3-acetic acid (IAA) and siderophores were measured. Whole-genome sequencing and phylogenetic analysis were also performed. Results Field trials showed that ABP-B9 enhanced crop yield in lettuce, spinach, and celery, improving root development, photosynthetic efficiency, flavonoid levels, and nitrogen status. The production of IAA and siderophores was confirmed in vitro . Plant responses were observed as early as five days after application. Genomic analysis revealed that ABP-B9 belongs to the Pseudomonas genus and is closely related to P. seleniipraecipitans . Its genome (4,602,210 bp; 61.46% GC content) includes 4,247 protein-coding genes, 12 rRNAs, and 66 tRNAs. Discussion ABP-B9 is a novel, non-pathogenic Pseudomonas strain with clear biostimulant activity. Its ability to enhance plant growth and increase crop yield, combined with its safety profile, supports its potential use in sustainable agriculture. Future studies should explore its application across different crops and environmental conditions.

Genomic insights into the antifungal and plant growth promoting traits of Pseudomonas plecoglossicida NAN2 isolated from the rice rhizosphere

2025-06-25

K. Nandhini , Gowrisankar Ganesan , Sellamuthu Iyappan | Plant Science Today

Plant growth promoting rhizobacteria (PGPRs) are beneficial microorganisms that inhabit the rhizosphere and enhance plant growth through various mechanisms. In this study, a PGPR strain designated NAN2 was isolated from … Plant growth promoting rhizobacteria (PGPRs) are beneficial microorganisms that inhabit the rhizosphere and enhance plant growth through various mechanisms. In this study, a PGPR strain designated NAN2 was isolated from the rice rhizosphere and demonstrated multiple plant growth-promoting traits, including the production of hydrogen cyanide (HCN), ammonia, indole-3-acetic acid (IAA), phosphate solubilization and antifungal activity against Magnaporthe oryzae. Complete genome sequencing and annotation of strain NAN2 revealed a genome size of 5356785 base pairs (bp) with a GC content of 62 %, comprising 227 contigs, 4807 coding sequences (CDSs) and a total of 4960 genes. Notably, the genome contains a nonribosomal peptide synthetase (NRPS) gene cluster associated with the biosynthesis of rhizomides (A, B and C). These results suggest that NAN2 has strong potential as an environmentally resilient biocontrol agent that can protect plants from invasive diseases. To our knowledge, this is the first genomic analysis of Pseudomonas plecoglossicida NAN2 isolated from rice fields, providing valuable insights into its biocontrol capabilities and plant growth promoting (PGP) properties.

Diversity of endophytic bacteria in mulberry (Morus spp.) scions with different genetic resources

2025-06-24

Yunfei Zhang , Yu Qin , Zeyu Liu +3 more | Frontiers in Microbiology

Endophytic bacteria in plants play crucial roles in promoting plant growth, facilitating nutrient acquisition, and enhancing stress tolerance. Although many studies have recently investigated endophytic bacteria in plants, the characteristics … Endophytic bacteria in plants play crucial roles in promoting plant growth, facilitating nutrient acquisition, and enhancing stress tolerance. Although many studies have recently investigated endophytic bacteria in plants, the characteristics of endophytic bacterial communities in germplasm resource populations have rarely been reported. In this study, we investigated the endophytic bacterial communities of 21 mulberry scions, representing both wild and cultivated resources, all grafted onto a common rootstock and grown under identical cultivation conditions. High-throughput sequencing of 16S rRNA amplicons was performed using the Illumina MiSeq platform. The results revealed a total of 10 phyla, 31 classes, 50 orders, 50 families, and 113 genera of endophytic bacteria in the mulberry scions. The dominant phylum was Proteobacteria (89.07%), followed by Firmicutes (5.20%) and Actinobacteria (3.10%). At the genus level, Sphingomonas (32.84%), Methylobacterium-Methylorubrum (18.64%), and Aureimonas (8.76%) were the predominant genera enriched in the scion. Wild scions exhibited more complex endophytic bacterial communities compared to cultivated scions. Among the wild germplasm, XZBS and XZMK, originating from Tibet, China, displayed distinctive Actinobacteria signatures, suggesting a potential legacy of primitive geographic adaptation. Co-occurrence network analysis indicated that Sphingomonas and Methylobacterium-Methylorubrum acted as keystone taxa, forming critical bridges within the endophytic bacterial community network in the scions. Functional predictions further indicated that endophytic bacteria from wild species showed a greater metabolic capacity for aromatic compounds, amino acids, and carbohydrates compared with those from cultivated species. Moreover, analyses of the mulberry genetic population structure and endophytic bacterial community composition suggested that differentiation between wild and cultivated resources was associated with differences in endophytic bacterial communities. This study provides new insights into the diversity of endophytic bacteria among different mulberry germplasm resources and highlights geographically unique taxa, advancing our understanding of microbiome-driven adaptation in perennial grafted plants. It also offers a valuable reference for the future utilization of functional endophytic bacteria in mulberry improvement.

Plant–Microbe Interaction

2025-06-24

Rajni Yadav , Siril Singh , Sabir Hussain +1 more | CRC Press eBooks

Spent mushroom substrate amendment induces suppressiveness against cucumber Fusarium wilt through changes in the rhizosphere microbiome

2025-06-24

Yuanhang Qu , Tiancong Liu , Lihong Dong +5 more | Plant and Soil

Evaluation of the efficient propagation of Rhizophagus intraradices and its inoculation effects on rice

2025-06-24

Feng Shi , Xinghao Wang , Xue He +4 more | Applied and Environmental Microbiology

Arbuscular mycorrhizal fungi (AMF) are a key group of fungi closely associated with agricultural production within soil microbial communities. However, large-scale propagation of AMF inoculum faces various challenges, limiting our … Arbuscular mycorrhizal fungi (AMF) are a key group of fungi closely associated with agricultural production within soil microbial communities. However, large-scale propagation of AMF inoculum faces various challenges, limiting our ability to obtain and utilize these inocula on a broad scale. To address this, we designed a monolayer mesh cultivation system employing a hydroponic approach for propagating arbuscular mycorrhizal fungi, specifically Rhizophagus intraradices. We conducted a comparative analysis of quality and inoculation efficiency between the water culture inoculum (w-Ri) and traditional soil-based inoculum (s-Ri). Our findings revealed the following. (i) The propagation cycle of w-Ri inoculum is 35 days and only 23% of the 150-day cycle required for s-Ri inoculum. (ii) The spore density, viability, and purity of w-Ri inoculum are 5.25 times, 1.09 times, and 1.26 times higher, respectively, than those of s-Ri inoculum. (iii) The w-Ri inoculants demonstrate effects on enhancing rice biomass, root morphology, and photosynthesis that are consistent with those of the s-Ri inoculants, while requiring only 10% of the application rate of the s-Ri inoculants. These results provide crucial theoretical references for establishing a pure and efficient arbuscular mycorrhizal fungus propagation system and its promotion and application.IMPORTANCEThe development of a monolayer mesh hydroponic cultivation system for propagating Rhizophagus intraradices offers a significant advancement in overcoming the challenges of large-scale AMF inoculum production, which is critical for enhancing agricultural sustainability. The comparative analysis of water culture-based (w-Ri) and traditional soil-based (s-Ri) inoculum demonstrates the superior efficiency of the w-Ri system in terms of propagation speed, spore density, and inoculum quality, highlighting its potential for large-scale application in farming practices. The findings that w-Ri inoculants are equally effective in promoting plant growth while requiring only a fraction of the application rate of s-Ri inoculants underscore the potential for reducing both cost and environmental impact in agricultural inoculation practices.

Delayed Chlorosis in Arabidopsis Ecotype Dijon‐G During Bacterial Infection and Dark‐Induced Senescence

2025-06-24

Young Hee Lee , Yun Jeong Kim , Hee Jin Park +2 more | Physiologia Plantarum

ABSTRACT Comparative evaluation of defence responses in different Arabidopsis ecotypes to pathogens is useful for understanding how plants acquire disease resistance and finding valuable genetic resources for disease resistance. In … ABSTRACT Comparative evaluation of defence responses in different Arabidopsis ecotypes to pathogens is useful for understanding how plants acquire disease resistance and finding valuable genetic resources for disease resistance. In this study, leaf chlorosis was delayed in Arabidopsis ecotype Dijon‐G (Di‐G) in response to Xanthomonas campestris pv. campestris ( Xcc ) 8004 infection, as well as continuous darkness compared to the ecotype Columbia‐0 (Col‐0). However, Xcc bacterial proliferation within Di‐G was slightly higher in Col‐0. The Xcc infection led to lower expression of several pathogenesis‐related genes ( PDIOX, GLIP1 and PAD4 ) and senescence‐related genes ( DIN6 and SAG12 ) in Di‐G. Dark‐induced leaf senescence was delayed in detached Di‐G leaves, showing a higher chlorophyll content than that of Col‐0. Exogenous SA did not change the chlorophyll loss in the Xcc‐ inoculated Col‐0 or Di‐G leaves, but SA limited Xcc growth in Col‐0 but not in Di‐G. SA pretreatment compromised chlorophyll loss in Col‐0 during dark‐induced leaf senescence, but it remained unaltered in Di‐G. These results show that Di‐G may have more efficient machinery for attenuating chlorophyll degradation during Xcc bacterial infection and continuous darkness than Col‐0. The different sensitivities to exogenous SA in Col‐0 and Di‐G suggest that the two ecotypes have adapted differently to their natural habitats in terms of plant immunity and leaf senescence.

Planthopper protein Nlsp5 is essential for salivary sheath formation and acts as a HAMP inducing plant resistance to insects

2025-06-23

Liangxuan Qi , Jing Li , Han Wang +4 more | Plant Biotechnology Journal

Summary During herbivore feeding, plants can recognize herbivore‐associated molecular patterns (HAMPs) present in saliva and trigger pattern‐triggered immunity (PTI). Piercing‐sucking insects secrete gel saliva, forming salivary sheaths that aid in … Summary During herbivore feeding, plants can recognize herbivore‐associated molecular patterns (HAMPs) present in saliva and trigger pattern‐triggered immunity (PTI). Piercing‐sucking insects secrete gel saliva, forming salivary sheaths that aid in feeding. However, the role of proteins within these salivary sheaths in modulating plant defences remains poorly understood. In this study, we identified a novel HAMP, Nlsp5, from the salivary sheath of the brown planthopper ( Nilaparvata lugens , BPH). Nlsp5 is a planthopper‐specific protein and acts as an elicitor of BAK1‐dependent PTI responses in both tobacco and rice plants. Moreover, the 19‐amino‐acid peptide (NP19) within Nlsp5 functions as a minimal immunogenic epitope, which is specifically recognized by plants, stimulating jasmonic acid and hydrogen peroxide pathways. Through exogenous treatment with synthetic NP19 and overexpressing Nlsp5 in rice, we further found that the induced defence responses not only impaired planthopper performance directly but also triggered the emission of volatile compounds that attract a common parasitoid. Additionally, NP19 treatment enhanced the resistance of rice, tobacco, and cotton to several chewing and sap‐sucking insects. However, silencing Nlsp5 in BPH disrupted salivary sheath formation, reducing insect feeding efficiency. This study demonstrates that Nlsp5 from the BPH salivary sheath acts as an unavoidable HAMP, triggering resistance in multiple plants to various insect pests. The critical role of this protein in insect feeding precludes evolutionary adaptations to evade detection by plants.

Enhancement of Tomato Growth Through Rhizobacteria and Biocontrol of Associated Diseases

2025-06-23

Hasna El hjouji , Redouan Qessaoui , Salahddine Chafiki +5 more | Life

The purpose of this study was to investigate the growth-promoting effects of four rhizobacterial isolates (RS60, RS65, RS46, and RP6) isolated from the tomato rhizosphere. These isolates were screened for … The purpose of this study was to investigate the growth-promoting effects of four rhizobacterial isolates (RS60, RS65, RS46, and RP6) isolated from the tomato rhizosphere. These isolates were screened for key plant growth-promoting rhizobacteria (PGPR) mechanisms, including ammonia production, nitrogen fixation, phosphate solubilization, indole-3-acetic acid (IAA) production, and siderophore synthesis. Their potential to enhance seed germination and tomato plant growth was investigated in controlled and greenhouse conditions. Four isolates exhibited multiple PGPR attributes, notably IAA and ammonia production as well as phosphate solubilization. The results revealed that these strains significantly enhanced tomato seed germination and shoot growth in vitro, with RS65 showing the highest germination rate (70%). However, no significant differences in early seedling responses were observed under greenhouse conditions when compared to the control. Thirty days after inoculation, greenhouse results revealed that the four studied strains significantly increased growth metrics including shoot length, number of leaves, collar diameter, and dry weight. The isolate RP6 showed a significant effect on the growth of the plant, with an average shoot length of 34.40 cm and nine leaves per plant. In vitro antagonism assays demonstrated that isolates RS60, RS65, and RP6 effectively inhibited the growth of Botrytis cinerea, Alternaria alternata, and Oidium lycopersici, with inhibition rates exceeding 65%. These antagonistic activities were linked to the production of hydrolytic enzymes (chitinase, cellulase, pectinase, protease), siderophores, and hydrogen cyanide (HCN). Molecular identification through 16S rRNA gene sequencing confirmed the isolates as Bacillus cereus (RS60), Bacillus pumilus (RS46), Bacillus amyloliquefaciens (RP6), and Bacillus velezensis (RS65), each showing over 97% sequence similarity with reference strains. These findings underscore the potential of the selected Bacillus spp. as promising biofertilizers and biocontrol agents for sustainable tomato cultivation and support their inclusion in integrated disease and nutrient management strategies.

Rhizosphere Growth-Promoting Bacteria Enhance Oat Growth by Improving Microbial Stability and Soil Organic Matter in the Saline Soil of the Qaidam Basin

2025-06-23

Xin Jin , Xinyue Liu , Jie Wang +3 more | Plants

The Qinghai–Tibet Plateau, a critical ecological barrier and major livestock region, faces deteriorating grasslands and rising forage demand under its harsh alpine climate. Oat (Avena sativa L.), valued for its … The Qinghai–Tibet Plateau, a critical ecological barrier and major livestock region, faces deteriorating grasslands and rising forage demand under its harsh alpine climate. Oat (Avena sativa L.), valued for its cold tolerance, rapid biomass accumulation, and ability to thrive in nutrient-poor soils, can expand winter feed reserves and partly alleviate grazing pressure on native rangelands. However, genetic improvement alone has not been sufficient to address the environmental challenges. This issue is particularly severe in the Qaidam Basin, where soil salinization, characterized by high pH, poor soil structure, and low nutrient availability, significantly limits crop performance. Rhizosphere growth-promoting bacteria (PGPR) are environmentally friendly biofertilizers known to enhance crop growth, yield, and soil quality, but their application in the saline soil of the Qaidam Basin remains limited. We evaluated two PGPR application rates (B1 = 75 kg hm−2 and B2 = 150 kg hm−2) on ‘Qingtian No. 1’ oat, assessing plant growth, soil physicochemical properties, and rhizosphere microbial communities. The results indicated that both treatments significantly increased oat productivity, raised the comprehensive growth index, augmented soil organic matter, and lowered soil pH; B1 chiefly enhanced above-ground biomass and fungal community stability, whereas B2 more strongly promoted root development and bacterial community stability. Structural equation modeling showed that PGPR exerted direct effects on the comprehensive growth index and indirect effects through soil and microbial pathways, with soil properties contributing slightly more than microbial factors. Notably, rhizosphere organic matter, fungal β-diversity, and overall microbial community stability emerged as positive key drivers of the comprehensive growth index. These findings provide a theoretical basis for optimizing PGPR dosage in alpine forage systems and support the sustainable deployment of microbial fertilizers under saline soil conditions in the Qaidam Basin.

Rhizoctonia solani Secretes RsCAP3 to Target Nb14–3–3b, Interfering with Hormone-Mediated Resistance in Nicotiana benthamiana

2025-06-23

Jun Wang , Jiaxin Zhang , Xiaofeng Dai +4 more | Journal of Agricultural and Food Chemistry

The necrotrophic phytopathogen Rhizoctonia solani causes leaf spot and root rot in tobacco, which significantly reduce the yield and quality of the crop. Recently, much attention has been paid to … The necrotrophic phytopathogen Rhizoctonia solani causes leaf spot and root rot in tobacco, which significantly reduce the yield and quality of the crop. Recently, much attention has been paid to R. solani effectors, but only a few of them have been characterized. Here, we identified a CAP domain-containing protein, RsCAP3, with a functional signal peptide, which triggers slight cell death on tobacco leaves. Meanwhile, RsCAP3 dramatically induces salicylic acid (SA) signaling but inhibits jasmonic acid (JA) signaling, increasing the plant's susceptibility to R. solani. Moreover, we demonstrated that RsCAP3 interacts with Nb14-3-3b, a negative regulator of tobacco resistance to R. solani. Correspondingly, we also found that transient expression of Nb14-3-3b activates SA signaling while suppressing JA signaling. Based on these results, we propose that RsCAP3 hijacks Nb14-3-3b to disrupt JA and SA pathways, thereby facilitating the infection of R. solani. Our findings highlight a novel virulence strategy in which R. solani interferes with the JA-/SA-mediated defense response.

β-Elemonic acid mediated enrichment of Paenibacillus to help Salvia miltiorrhiza Bunge alleviate drought stress

2025-06-23

Hongmei Jia , Jie Zhou , Wencheng Zhao +2 more | Microbiome

Microorganisms can improve the adaptability of crops to drought and high-temperature stress. However, the changes of rhizosphere microbial communities under climate stress and the potential mechanisms driving microbial changes remain … Microorganisms can improve the adaptability of crops to drought and high-temperature stress. However, the changes of rhizosphere microbial communities under climate stress and the potential mechanisms driving microbial changes remain poorly understood. In this study, the medicinal plant Salvia miltiorrhiza was used as the research object. ITS, 16S rRNA amplicon sequencing, and liquid chromatography-mass spectrometry-based metabolomics were integrated to investigate its physiological and biochemical responses to drought, high-temperature, and combined drought-high temperature under greenhouse. Additionally, we determined the seedling weight, leaf water content, active ingredient content of underground part, and the content of chlorophyll, leaf nitrogen, phosphorus, and potassium. The results demonstrated that microorganisms can alleviate stress by enhancing the water retention capacity of S. miltiorrhiza leaves; TD group increased by about 13%, promoting nutrient absorption; and the chlorophyll content of group D increased by about 78%, boosting photosynthetic efficiency and increasing the levels of stress-resistant compounds. We found that bacteria exhibited greater sensitivity to climatic stress factors, with Paenibacillus being significantly enriched only in the stress-treated group. Moreover, the synthetic community comprising Paenibacillus was confirmed to help S. miltiorrhiza alleviate drought stress. We further found that β-elemonic acid, a triterpene acid secreted by plant roots, specifically enriched Paenibacillus under drought stress. In addition, β-elemonic acid significantly promoted the growth of S. miltiorrhiza in the presence of Paenibacillus under drought stress. Our findings suggest that S. miltiorrhiza enrich beneficial Paenibacillus to combat drought stress through the secretion of the key metabolite β-elemonic acid. Video Abstract.

Nutrient-Driven Metabolic Activation and Microbial Restructuring Induced by Endophytic Bacillus in Blight-Affected Forest Soils

2025-06-23

Quan Yang , Shimeng Tan , Anqi Niu +2 more | Microorganisms

The climate-driven acceleration of forest disease outbreaks has intensified the demand for sustainable biocontrol strategies. In this study, we evaluated the effects of the endophytic bacterium Bacillus amyloliquefaciens csuftcsp75 on … The climate-driven acceleration of forest disease outbreaks has intensified the demand for sustainable biocontrol strategies. In this study, we evaluated the effects of the endophytic bacterium Bacillus amyloliquefaciens csuftcsp75 on soil properties, microbial communities, and functional metabolism in soils affected by Pinus massoniana shoot blight. Soil physicochemical analysis, carbon substrate utilization profiling (AWCD), and diversity indices (the Shannon, Simpson, and McIntosh indices) were integrated to assess the microbial responses under different inoculation treatments. The csuftcsp75 treatment significantly improved soil nutrient availability—especially available phosphorus and potassium—and was associated with enhanced microbial metabolic activity and sustained functional diversity. Principal component analysis and correlation mapping revealed strong associations between labile nutrients and microbial responses. Comparative analysis showed that csuftcsp75 promoted a balanced and metabolically rich microbial community, while less compatible strains exhibited transient or unstable effects. These findings support a dual-pathway model wherein nutrient-driven metabolic activation and ecological integration jointly determine biocontrol efficacy. This study highlights the importance of matching microbial inoculants with local soil environments to optimize functional outcomes. This work provides a theoretical basis for applying endophytic Bacillus in forest disease management and contributes to the development of ecologically coherent biocontrol strategies.

Effect of combined treatment with Bacillus amyloliquefaciens H-2-5 and illite on mitigating salt stress in Panicum miliaceum

2025-06-23

Sang-Mo Kang , Md. Injamum-Ul-Hoque , Ji‐In Woo +6 more | Applied Biological Chemistry

Abstract Soil salinity is a significant environmental challenge that negatively affects crop yield. Growth-promoting bacteria (GPB), such as Bacillus amyloliquefaciens H-2-5, offer a promising biological approach to enhance plant tolerance … Abstract Soil salinity is a significant environmental challenge that negatively affects crop yield. Growth-promoting bacteria (GPB), such as Bacillus amyloliquefaciens H-2-5, offer a promising biological approach to enhance plant tolerance under saline conditions. This study investigates the beneficial role of B. amyloliquefacien s H-2-5, in combination with the clay mineral illite, in alleviating salt stress in Panicum miliaceum . Under 150 mM NaCl stress, the combined treatment significantly improved plant growth, increasing shoot and root lengths by 44.3% and 40.9%, respectively, compared to untreated stressed plants. The treatment enhanced relative water content (RWC) (18.8%) and chlorophyll concentration (36.3%), indicating improved water status and photosynthetic capacity. Moreover, elevated levels of flavonoids (57.1%) and polyphenols (27.3%) reflected the stimulation of antioxidant responses, while reduced superoxide dismutase (SOD) and DPPH activities suggested lowered oxidative damage. Elemental analysis revealed reduced sodium uptake (35.7%) and increased potassium accumulation (20.6%), resulting in a more favorable Na⁺/K⁺ ratio. These findings highlight the significant contribution of B. amyloliquefaciens H-2-5 as a GPB that not only promotes plant growth but also strengthens physiological and biochemical mechanisms against salt-induced stress, supporting its potential as a sustainable tool for improving crop resilience in saline environments.

5-Fluoroindole Inhibits Its Putative Target Methionine Synthase and Pseudomonas syringae pv. actinidiae Virulence

2025-06-23

Chun Zhang , Kunhong Zhao , Zilin Wu +5 more | Journal of Agricultural and Food Chemistry

Bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) severely impacts global kiwifruit production. This study shows that 5-fluoroindole exerts significant bactericidal activity against Psa, with a half-maximal effective concentration … Bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) severely impacts global kiwifruit production. This study shows that 5-fluoroindole exerts significant bactericidal activity against Psa, with a half-maximal effective concentration (EC50) of 15.34 μg/mL, demonstrating a higher efficacy than the positive control copper hydroxide (EC50 = 58.65 μg/mL). 5-Fluoroindole disrupts membrane integrity, induces oxygen species (ROS) accumulation, and triggers apoptosis in Psa. Transcriptome analysis reveals that 5-fluoroindole treatment increased the expression of the methionine synthase II (MetE) gene by 6.28 fold compared with the expression of this gene in the control (CK) group. Microscale thermophoresis and isothermal titration calorimetry show that the dissociation constants of the binding of 5-fluoroindole to MetE protein are 0.33 and 8.55 μM, respectively. Molecular docking experiments indicate that Asp693 is a key binding site and that there is no specific binding between 5-fluoroindole and the Psa MetED693A mutant. This study provides valuable insights for developing effective agents to control kiwifruit bacterial canker.

Biocontrol of the black-spot disease pathogen (Alternaria alternata) in Dioscorea opposita by native endophytic bacterium Bacillus sp. E-Do8

2025-06-22

Chaochuang Li , Longlong Ma , Houmin Wang +5 more | BioControl

Antagonistic potential and analytical profiling of plant probiotic bacteria using chromatography and mass spectrometry techniques against Botrytis cinerea and Fusarium oxysporum

2025-06-21

Gottumukkala Hiranmayee , Sarada Prasanna Mallick , Golamari Siva Reddy | Bioresources and Bioprocessing

Abstract Plant probiotics are bacteria that play a significant role in enhancing plant growth and health. To understand the interactions between plant probiotics and host plants, a comprehensive approach of … Abstract Plant probiotics are bacteria that play a significant role in enhancing plant growth and health. To understand the interactions between plant probiotics and host plants, a comprehensive approach of antagonistic activity and analytical methods such as high-performance liquid chromatography (HPLC), gas chromatography‒mass spectrometry (GC‒MS), and Fourier transform infrared (FT‒IR) spectroscopy, were employed. The previously isolated bacterial strains, namely, Corynebacterium accolens strain CNTC Th1/57 , Bacillus rugosus strain SPB7, Lactobacillus pasteurii DSM 23907 and Cytobacillus firmus strain NBRC 15306, were exposed to antagonistic testing against Botrytis cinerea and Fusarium oxysporum. Considering the results of the antagonistic activity both in vitro and statistically, the bacterial strains Bacillus rugosus strain SPB7 and Lactobacillus pasteurii DSM 23907 presented greater zones of inhibition. Hence these bacteria were moved to obtain comprehensive insights into the chemical composition. HPLC and GC‒MS resulted in the identification of phenols and organic acids. These results were further confirmed by FT-IR, which revealed a peak at 3500 cm −1 for Bacillus rugosus strain SPB7, where O–H, aromatic C-H and aromatic C = C stretching vibrations were also observed at 3069 and 1549 cm −1 . The peak at 1736 cm −1 corresponds to the carboxyl group (-COOH) as the functional group with respect to Lactobacillus pasteurii DSM 23907. Further confirmation was performed by observing the other absorption bands at 3451 cm −1 and 2958 cm −1 , indicating the presence of hydroxyl group (O–H) and alkyl group (C-H) stretching vibrations, thus confirming their potential for the production of phenols and organic acids, respectively, by bacteria. This findings would make a way to explore plant diseases, tolerance against pathogens, and also study ecological role of these bacteria in plant communities. Graphical Abstract

Synergistic effects of a biocompatible PGPR consortium on growth promotion and verticillium wilt suppression in tomato seedlings

2025-06-21

Salma Oulad Ziane , Zahra Imehli , Zainab El Alaoui Talibi +3 more | Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology

Identification of a Novel Pathogen of Peanut Root Rot, Ceratobasidium sp. AG-A, and the Potential of Selected Bacterial Biocontrol Agents

2025-06-21

Y. Li , Xia Zhang , Xinying Song +4 more | Journal of Fungi

Peanut root rot poses a significant threat to global peanut production. In order to identify the new pathogen of peanut root rot in Shandong province, China, and to screen the … Peanut root rot poses a significant threat to global peanut production. In order to identify the new pathogen of peanut root rot in Shandong province, China, and to screen the effective antagonistic biocontrol strains against the identified pathogen, ten symptomatic plants from a peanut field (10% disease incidence) of Rongcheng were sampled for pathogen isolation. The predominant isolate RC-103 was identified as Ceratobasidium sp. AG-A through morphological characterization and phylogenetic analysis of ITS and RPB2 sequences. Pathogenicity was confirmed via Koch’s postulates. Three potent biocontrol strains, namely Bacillus subtilis LY-1, Bacillus velezensis ZHX-7, and Burkholderia cepacia Bc-HN1, were screened for effective antagonism against isolate RC-103 by dual-culture analysis. Their cell suspensions could significantly inhibit the hyphal growth of isolate RC-103, with the percentage inhibition of 54.70%, 45.86%, and 48.62%, respectively. Notably, the percentage inhibition of 10% concentration of the cell-free culture filtrate of B. subtilis LY-1 was as high as 59.01%, and the inhibition rate of volatile organic compounds of B. cepacia Bc-HN1 was 48.62%. Antagonistic mechanisms primarily involved the induction of hyphal abnormalities. In addition, the culture filtrate of these biocontrol bacteria significantly promoted the growth of peanut and increased the resistance of peanut plants to isolate RC-103, with the biocontrol efficiency reaching 41.86%. In summary, this study identified a novel pathogen of peanut root rot, Ceratobasidium sp. AG-A, which was reported for the first time in China, and screened three highly effective antagonistic biocontrol strains against Ceratobasidium sp. AG-A isolate RC-103, providing the scientific basis to study the epidemiology and management of this disease.

Wild wisdom meets cultivation: comparative rhizomicrobiome analysis unveils the key role of Paraburkholderia in growth promotion and disease suppression in Coptis chinensis

2025-06-21

Xianhe Cao , Qingjun Yuan , Chengcheng Hu +7 more | Microbiome

The sustained monoculture and irregular planting practices rendered the cultivated Coptis chinensis more prone to various diseases compared to its wild counterparts. Rewilding the rhizomicrobiome of cultivated plants has emerged … The sustained monoculture and irregular planting practices rendered the cultivated Coptis chinensis more prone to various diseases compared to its wild counterparts. Rewilding the rhizomicrobiome of cultivated plants has emerged as a promising strategy to promote plant growth, but ancestral microbiota suitable for C. chinensis remain largely uncharted. The amplicon data analyses revealed that habitat transition strongly influenced the rhizosphere microbial communities. The rhizomicrobiomes of wild C. chinensis encompassed a more diverse array of ecological groups and exhibited a greater functional diversity compared to their cultivated counterparts. A higher proportion of beneficial fungi was observed in the rhizosphere of wild C. chinensis, while the cultivated plants had a higher population of pathogenic fungi. Furthermore, a well-documented plant-growth-promoting rhizobacterium genus, Paraburkholderia, was found to play an essential role in the resistance of the wild C. chinensis to potential disease caused by Ilyonectria. Two strains of Paraburkholderia (Paraburkholderia nemoris and Paraburkholderia phytofirmans) were isolated, and in vitro experiments confirmed that these isolates possess various growth-promoting properties and antagonistic activities against known pathogens for C. chinensis root rot. Both of the Paraburkholderia isolates could markedly promote the plant immune response and enhance the overall health of the cultivated C. chinensis. By a comprehensive comparison of the rhizosphere microbiome between wild and cultivated C. chinensis, the promising bacterial genus Paraburkholderia was identified as a beneficial microbe significantly promoting the growth of C. chinensis, providing pivotal insights for future endeavors aimed at engineering the rhizosphere microbiome of C. chinensis, as well as other medicinal herbs. Video Abstract.

Nucleoside Derivatives Target Magnaporthe oryzae Appressoria Function and Nucleotide Metabolism for Fungal Disease Control

2025-06-20

Fuyan Li , Hong Hu , J. Zhang +7 more | Journal of Agricultural and Food Chemistry

Novel fungicides are crucial for managing plant diseases. Magnaporthe oryzae, a major threat to global rice production, serves as a model plant pathogen. Nucleoside compounds, known for their low toxicity … Novel fungicides are crucial for managing plant diseases. Magnaporthe oryzae, a major threat to global rice production, serves as a model plant pathogen. Nucleoside compounds, known for their low toxicity and unique mechanisms, show potential for controlling plant pathogenic fungi but remain underexplored. In this study, we evaluated the antifungal effects of nucleoside-derived compounds on M. oryzae, focusing on their impact on appressorium formation, turgor pressure, and pathogenicity. These compounds significantly reduced M. oryzae virulence by inhibiting appressorium function and affecting glycogen and lipid metabolism. They also altered cAMP levels and disrupted cell cycle progression, autophagy, and peroxisome division, impacting nucleotide metabolism with APT1 and XPT1 as potential targets. Additionally, these inhibitors demonstrated broad-spectrum antifungal activity and synergistic effects with isoprothiolane. Our findings suggest that nucleoside-derived compounds are effective antifungal agents with broad application prospects in plant disease control.

The Rice-Microbe Nexus: Unlocking Productivity Through Soil Science

2025-06-20

Aiman Hakim Bin Aminurrasyid , Asmuni Mohd Ikmal , Kalaivani Nadarajah | Rice

Rice is a staple crop and a primary food source for nearly half of the global population. Its cultivation is heavily dependent on irrigation systems, which is crucial in determining … Rice is a staple crop and a primary food source for nearly half of the global population. Its cultivation is heavily dependent on irrigation systems, which is crucial in determining productivity. Beyond irrigation, the genetic characteristic of rice significantly influences its growth, resilience, and yield. These factors are closely connected to the soil microbiome within the rhizosphere, where interactions between plants, soil, and microbes occur, ultimately affecting agricultural outcomes. Different rice genotypes and agricultural practices shape soil microbiomes uniquely, impacting crop resilience and yield. Additionally, the growth stage of rice influences root exudation patterns, which in turn affects the composition and functionality of the rhizospheric microbiome. As the plant matures, the quantity and quality of root exudates evolve alongside its physiological changes, further modifying microbial communities in the surrounding soil. This review explores the complex interplay among irrigation strategies, rice genotypes, and growth phases, examining their collective impact on soil microbial diversity, offering insights into leveraging soil microbiomes for sustainable crop management and enhanced production. In addition it also highlights biotechnological tools and approaches that may be utilized in sustainable rice farming.

Phytopathogen Effector Biology in the Burgeoning AI Era

2025-06-20

Darcy Jones , Sylvain Raffaele | Annual Review of Phytopathology

Plant pathogens secrete effectors to facilitate infection and manipulate host physiological and immune responses. Effector proteins are challenging to characterize because of their sequence and functional diversity, rapid evolution, and … Plant pathogens secrete effectors to facilitate infection and manipulate host physiological and immune responses. Effector proteins are challenging to characterize because of their sequence and functional diversity, rapid evolution, and host-specific interactions. Recent advances in artificial intelligence (AI), particularly in protein biology, offer new opportunities for identifying and characterizing effector proteins and understanding their evolutionary processes. This review discusses recent progress in applying AI to effector biology, focusing on identification, functional characterization, and evolution. Key areas include subcellular localization prediction, protein structural modeling with tools like AlphaFold, and the use of pretrained protein language models. AI promises to complement existing experimental and computational approaches and further accelerate the investigation of effector protein functions and their evolutionary histories, even in the absence of clear sequence similarity or known functional domains.

Characterization of PAMP-induced peptides and mechanistic insights into SlPIP2-mediated defense in tomato

2025-06-20

Ruirui Yang , Hongbo Wei , Jiaxuan Zhu +4 more | Plant Cell Reports

Cooperative Interactions Between Bacillus and Lysobacter Enhance Consortium Stability and Fusarium Wilt Suppression in Cucumber

2025-06-20

Xinli Sun , Riyan Xia , Jiyu Xie +7 more | Research Square (Research Square)

<title>Abstract</title> The rhizosphere microbiome plays a pivotal role in plant health by mediating interactions between hosts, beneficial microbes, and pathogens. However, the ecological mechanisms underlying microbial consortia that suppress soil-borne … <title>Abstract</title> The rhizosphere microbiome plays a pivotal role in plant health by mediating interactions between hosts, beneficial microbes, and pathogens. However, the ecological mechanisms underlying microbial consortia that suppress soil-borne diseases remain largely unexplored. In this study, we investigated how the biocontrol bacterium <italic>Bacillus velezensis</italic> SQR9 influences the assembly of the cucumber rhizosphere bacterial community in the presence of the pathogenic fungus <italic>Fusarium oxysporum</italic> FOC. Inoculation with <italic>B. velezensis</italic> SQR9 significantly enriched the genus <italic>Lysobacter</italic>, a group of known biocontrol bacteria potentially contributing to disease suppression. A meta-analysis of publicly available datasets revealed a positive correlation between <italic>Bacillus</italic> and <italic>Lysobacter</italic> abundances in healthy plant rhizospheres—a relationship absent in <italic>Fusarium</italic> wilt diseased soils—suggesting a conserved ecological association linked to disease suppression. Further mechanistic assays demonstrated that <italic>Lysobacter enzymogenes</italic> XL8, an antifungal bacterium isolated from the cucumber rhizosphere, formed synergistic biofilms with <italic>B. velezensis</italic> SQR9. Cross-feeding assays indicated that strain SQR9 facilitated the growth of <italic>L. enzymogenes</italic> XL8 through metabolic interactions, highlighting a cooperative mechanism that may stabilize the rhizosphere bacterial consortium. Greenhouse trials confirmed that this dual-species consortium outperformed single-species inoculations in suppressing <italic>Fusarium</italic> wilt, as evidenced by reduced pathogen abundance and enhanced plant growth. Together, our findings underscore the importance of microbial metabolic cooperation and biofilm-mediated coexistence in shaping rhizosphere community assembly and function, providing ecological insights for the development of synthetic microbial consortia aimed at sustainable plant disease management.

Elicitor from Trichothecium roseum Activates the Disease Resistance of Salicylic Acid, Jasmonic Acid, and Ca2+-Dependent Pathways in Potato Tubers

2025-06-20

Di Wang , Rong Liu , Haijue Zhang +4 more | Journal of Fungi

The effects of a fungal elicitor from Trichothecium roseum on signal pathways of salicylic acid (SA), jasmonic acid (JA), and Ca2+ in potato tubers were investigated. The results showed that … The effects of a fungal elicitor from Trichothecium roseum on signal pathways of salicylic acid (SA), jasmonic acid (JA), and Ca2+ in potato tubers were investigated. The results showed that fungal elicitor treatment effectively inhibited the lesion diameter of Fusarium sulphureum in vivo, which was 17.5% lower than that of the control. In addition, fungal elicitor treatment triggered an increase in O2− production and H2O2 content. The fungal elicitor enhanced the activities and gene expression levels of isochorismate synthase (ICS), phenylalanine ammonia lyase (PAL), allene oxide cyclase (AOC), allene oxide synthase (AOS), lipoxygenase (LOX), and Ca2+-ATPase. Furthermore, the fungal elicitor promoted an increase in calmodulin (CaM) content. Protective enzymes (dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), chitinase (CHI), and β-1,3-glucanase (Glu)) and disease-resistance-related genes (PR1, PR2, and PDF1.2) were induced to be upregulated by elicitor treatment. These results indicated that the fungal elicitor induced disease resistance by accelerating the accumulation of reactive oxygen species (ROS), activating SA, JA, and Ca2+ signaling, and upregulating resistance genes. The results of this study revealed the molecular mechanism of fungal elicitor-induced resistance in the potato, which provides a theoretical basis for the mining of new, safe, and efficient elicitor-sourced antifungal agents and is of great importance for the effective control of potato dry rot disease.

Auxin‐Producing Pseudomonas Recruited by Root Flavonoids Increases Rice Rhizosheath Formation through the Bacterial Histidine Kinase Under Soil Drying

2025-06-19

Feiyun Xu , Yongsen Wang , Jinyong Yang +7 more | Advanced Science

Abstract Rhizosheath formation is facilitated by root hair length, root exudates, the soil microbes, which collectively enhance plant resistance to drought. This process partly results from the complex interaction between … Abstract Rhizosheath formation is facilitated by root hair length, root exudates, the soil microbes, which collectively enhance plant resistance to drought. This process partly results from the complex interaction between root exudates and microbes, a relationship that remains poorly understood. The roles of root exudates and microbes in rhizosheath formation in rice under soil drying (SD) conditions are investigated. In tetraploid rice, rhizosheath formation under SD is approximately 70% greater than in diploid rice. Inoculation of diploid rice with the rhizosheath soil microbiota from tetraploid rice significantly enhanced rhizosheath formation under SD. The bacterial genus Pseudomonas is identified as the key taxon promoting rhizosheath formation in tetraploid rice under SD. Tetraploid rice exhibits significantly higher root flavonoid concentration than diploid rice under SD. Overexpression of the chalcone synthase gene ( OsCHS1 ), a key gene involved in flavonoid biosynthesis, led to a significant increase in the abundance of Pseudomonadaceae in diploid rice. Pseudomonas nitroreducens , isolated from the rhizosheath of tetraploid rice, demonstrates chemotactic attraction to flavonoids, but this behavior is not observed in histidine kinase mutant Δ cheA . Diploid and tetraploid rice inoculated with P. nitroreducens and IAA biosynthesis complemented strain Δ iaaM ‐c formed larger rhizosheath under SD than those inoculated with its IAA biosynthesis mutant Δ iaaM . These results suggest that auxin‐producing Pseudomonas , recruited by root flavonoids, enhances rice rhizosheath formation through the bacterial histidine kinase under SD. This finding may facilitate the improvement of environmental adaptation in polyploidy crops by regulating their interactions with beneficial soil microorganisms.

FgMsn2 negatively regulates general stress responses and autophagy in Fusarium graminearum

2025-06-19

Riliang Gu , Yunqing Jian , Zunyong Liu | Phytopathology Research

Abstract Effective adaptation to diverse stressors is essential for fungal survival and pathogenicity. The mechanisms underlying general stress responses in Fusarium graminearum , the pathogen responsible for Fusarium head blight … Abstract Effective adaptation to diverse stressors is essential for fungal survival and pathogenicity. The mechanisms underlying general stress responses in Fusarium graminearum , the pathogen responsible for Fusarium head blight (FHB) in cereal crops, remain unclear. In this study, we identify FgMsn2 as a negative regulator of general stress responses in F. graminearum . Deletion of FgMsn2 leads to resistance of F. graminearum to oxidative, osmotic, and cell wall stresses. Mechanically, FgMsn2 represses autophagy by inhibiting the expression of autophagy-related genes, including FgATG8 , and stress conditions trigger the cytoplasmic localization of FgMsn2. Additionally, the Δ FgMsn2 mutants show significantly reduced virulence on wheat, indicating the critical role of FgMsn2 in pathogenicity. These findings uncover a unique regulatory function of FgMsn2, which contrasts with its positive role in stress responses reported in other fungi, and provide valuable insights for developing novel strategies to manage FHB.

The Flowering Time Regulator FLK Acts Through the ROS Scavenging Gene CATALASE 2 in Pathogen Defense in Arabidopsis

2025-06-19

Matthew Fabian , Leah Vrydagh , Maria Cervasio +2 more | Plant Science

A Water-Soluble Probe for Visualizing Immune Activation for Microbial Resistance in Rice Crops via NIR-II Fluorescent Imaging

2025-06-19

Rong Li , Fang Zeng , Shuizhu Wu | Analytical Chemistry

Rice, a vital staple crop, provides sustenance for more than half of the global population, and its production needs to be increased to keep up with the growing global population, … Rice, a vital staple crop, provides sustenance for more than half of the global population, and its production needs to be increased to keep up with the growing global population, while plant diseases threaten the sustainability of rice production, causing significant crop losses and reducing harvest quality. The widespread use of chemical pesticides has raised concerns about environmental pollution, pesticide resistance, and economic burdens. Therefore, alternative, sustainable disease management strategies are urgently needed. One promising solution involves plant immunity inducers, which activate the plant's natural defense mechanisms to combat pathogens. However, the mechanisms underlying immune activation remain poorly understood, and effective tools for the real-time visualization of immune responses are lacking. In this study, we developed a water-soluble and biosafe D-A-D (donor-acceptor-donor)-type fluorescent probe for real-time visualization of immune activation in rice via near-infrared second-window (NIR-II) fluorescence imaging. The probe, featuring a unique electronic structure, with a diphenylaminoxanthene and a benzyl group being the electron donors, the benzo[cd]indolium being the electron acceptor, and a butylamino group for nitric oxide (NO) detection, allows the monitoring of NO production, a key signaling molecule in plant immunity. Our results show that the probe effectively detects NO generation in response to salicylic acid (SA), an immune inducer, and visualizes immune activation and consequent microbial resistance in rice via NIR-II fluorescent imaging. This approach could provide an effective means for obtaining valuable insights into plant immune dynamics and contribute to promoting sustainable agriculture and food security.

The histidine kinase <scp>PhpA</scp> regulates the biocontrol activity of <scp>Pseudomonas bijieensis 2P24</scp> through the Gac/Rsm signaling pathway

2025-06-19

R. Ren , Ting Zeng , Bo Zhang +2 more | Pest Management Science

Abstract BACKGROUND Histidine kinases in rhizosphere bacteria regulate physiological behaviors through two‐component systems (TCSs) in response to environmental cues. The RetS‐GacS/GacA multikinase network is critical for 2,4‐diacetylphloroglucinol (2,4‐DAPG) production and … Abstract BACKGROUND Histidine kinases in rhizosphere bacteria regulate physiological behaviors through two‐component systems (TCSs) in response to environmental cues. The RetS‐GacS/GacA multikinase network is critical for 2,4‐diacetylphloroglucinol (2,4‐DAPG) production and biocontrol activity in Pseudomonas bijieensis 2P24. However, the involvement of additional histidine kinases in this regulatory pathway remains unclear. RESULTS Genetic assay showed a mutation in phpA significantly reduced the expression of small non‐coding RNAs RsmY and RsmZ, thereby attenuating the expression of phlA and diminishing 2,4‐DAPG production of strain 2P24. Bacterial two‐hybrid assay demonstrated that PhpA interacted with RetS and GacS to influence the function of RetS and GacS. Additionally, PhpA modulated diverse cellular processes, including environmental information processes, genetic information processes, and secondary metabolism. CONCLUSION Collectively, these findings indicate that PhpA is a pivotal component of the RetS‐GacS/GacA signaling network, highlighting its role in fine‐tuning bacterial adaptation and biocontrol ability in P. bijieensis . © 2025 Society of Chemical Industry.

Microbial Metabolites: A Sustainable Approach to Combat Plant Pests

2025-06-19

S. Prabhu , R. Poorniammal , Laurent Dufossé | Metabolites

With the sustainable increase in agricultural productivity, the need for safer, environmentally friendly pesticide alternatives is also growing. Metabolites of microorganisms (bacteria, fungi, actinomycetes) are emerging as potential bioactive compounds … With the sustainable increase in agricultural productivity, the need for safer, environmentally friendly pesticide alternatives is also growing. Metabolites of microorganisms (bacteria, fungi, actinomycetes) are emerging as potential bioactive compounds for integrated pest and disease management. These compounds comprise amino acids, carbohydrates, lipids, organic acids, phenolics, peptides, alkaloids, polyketides, and volatile organic compounds. The majority of them have insecticidal, fungicidal, and nematicidal activities. In this review, the classifications, biosynthetic pathways, and ecological functions of primary and secondary metabolites produced by microorganisms are discussed, including their mechanisms of action, ranging from competition to systemic acquired resistance in host plants. The article highlights the importance of microbial genera (viz., Bacillus sp., Pseudomonas sp., Trichoderma sp., Streptomyces sp., etc.) in making chemicals and biopesticides for crop defense. We present the possible applications of microbial biosynthesis strategies and synthetic biology tools in bioprocess development, covering recent innovations in formulation, delivery, and pathway engineering to enhance metabolite production. This review emphasizes the significance of microbial metabolites in improving the plant immunity, yield performance, reduction in pesticide application, and the sustainability of an ecological, sustainable, and resilient agricultural system.

Exploration of Plant and Microbial Life at “El Chichonal” Volcano with a Sustainable Agriculture Prospection

2025-06-18

A Rios-Reyes , Katia Jamileth González-Lozano , Juan Pablo Cabral-Miramontes +6 more | Microbial Ecology

Active volcanic environments represent extreme habitats with underexplored potential for microbial bioprospecting. This study aimed to characterize pioneer vegetation and associated microbial diversity in the crater of "El Chichonal" volcano, … Active volcanic environments represent extreme habitats with underexplored potential for microbial bioprospecting. This study aimed to characterize pioneer vegetation and associated microbial diversity in the crater of "El Chichonal" volcano, with an emphasis on their potential applications in sustainable agriculture. A physicochemical analysis of the soil was performed, identifying acidic and nutrient-poor conditions. Three pioneer plant species were described: Tibouchina longifolia (dominant) and Poaceae spp. (co-dominant), and Palhinhaea cernua (non-dominant). A total of 311 microorganisms were predominantly bacteria, were isolated from soil, root, stem, and water samples. Bacillus cereus and Priestia megaterium were molecularly identified, and in vitro assays demonstrated their ability to fix nitrogen, produce auxins, and antagonize fungal pathogens (Alternaria solani, Botrytis cinerea, and Colletotrichum gloeosporioides). These results suggest that microorganisms adapted to extreme volcanic environments could be promising sources of plant growth-promoting bacteria (PGPB) with application in biological control.

Editing metacaspase (StMC7) gene enhances late blight resistance in Russet Burbank potato

2025-06-18

Bal Hari Poudel , Atul Sathe , Jacqueline C. Bede +1 more | PLoS ONE

Plants induce hypersensitive response programmed cell death (HR-PCD), upon biotrophic pathogen infection, to contain the pathogen to the point of infection. Apoptotic-like PCD (AL-PCD) has been reported upon prolonged hemibiotrophic … Plants induce hypersensitive response programmed cell death (HR-PCD), upon biotrophic pathogen infection, to contain the pathogen to the point of infection. Apoptotic-like PCD (AL-PCD) has been reported upon prolonged hemibiotrophic and necrotrophic pathogen infection in potato, to feed on the dead cells for their growth. In potato, silencing of the gene StHRC lead to the suppression of AL-PCD, thus increasing resistance to blights in potato. This was also associated with a significant reduction in the expression of the metacaspase gene StMC7 . Accordingly, the gene StMC7 was silenced in potato cultivar ‘Russet Burbank’ using CRISPR-Cas9 to improve disease resistance against late blight of potato caused by Phytophthora infestans . Following pathogen infection, the disease severity, pathogen biomass and StMC7 gene expression was lower in Stmc7 mutants as compared to wild type. Disease severity was also decreased in Alternaria solani inoculated Stmc7 mutants, compared to the wild type, suggesting possible multiple disease resistance in the Stmc7 knockdown mutants. This confirms that the silencing of StMC7 improves late blight disease resistance in potato.

A Colletotrichum -unique effector with the Cx 11 NC motif enhances plant NDPK2 kinase activity to suppress plant immunity

2025-06-18

Guangli Liu , Du You-Wei , Ming‐Hui Chen +7 more | Science Advances

Colletotrichum fungi cause destructive diseases among a wide range of hosts worldwide. We found that effector CfEC92 from C. fructicola specifically binds ATP through an unidentified ATP-binding domain, leading to … Colletotrichum fungi cause destructive diseases among a wide range of hosts worldwide. We found that effector CfEC92 from C. fructicola specifically binds ATP through an unidentified ATP-binding domain, leading to changes in the protein secondary structure. The residues Cys 26 , Asn 38 , and Cys 39 were critical for ATP binding with CfEC92, and mutations at these sites impaired the ability to suppress host immunity. CfEC92 interacted with MdNDPK2, a negative immune regulator in apple. The CfEC92-ATP complex altered the conformation of MdNDPK2, enhancing its affinity for ATP, and further increasing its autophosphorylation and kinase activity. The activated MdNDPK2 phosphorylated MdMPK3 to suppress host immunity. Homology and functional tests showed that the Cx 11 NC motif was highly conserved among Colletotrichum species, suggesting that CNC effectors represent a class of broad-spectrum virulence factors. Our findings revealed a mechanism by which Colletotrichum effectors cooperate with helper ATP to promote target protein phosphorylation and suppress host immunity.

Current status and future trends of eco-friendly management of postharvest fungal decays in tomato fruit

2025-06-18

Zhenshuo Wang , Menghua Wu , Qinhong Liao +3 more | npj Science of Food

Bacterial community shifts in Fusarium-induced avocado root rot and the antagonistic potential of Bacillus siamensis NB92

2025-06-18

Chengxian Wang , Zhijiao Song , Xue Li +1 more | Frontiers in Microbiology

Avocado root rot, driven by soil-borne fungi such as Fusarium spp., poses a major challenge to global avocado production. The rhizosphere microbiome is critical for plant health, yet the impact … Avocado root rot, driven by soil-borne fungi such as Fusarium spp., poses a major challenge to global avocado production. The rhizosphere microbiome is critical for plant health, yet the impact of root rot on bacterial community structure and its implications for disease management remain poorly understood. Here, we combined culture-independent 16S rDNA amplicon sequencing with culture-dependent isolation to characterize bacterial communities in healthy and Fusarium -infested avocado bulk and rhizosphere soils. Key beneficial taxa, notably Bacillus , were then isolated and evaluated for their antagonistic potential. Results showed that root rot significantly reduced rhizosphere bacterial α-diversity, altered community structure, and depleted phyla such as Actinobacteriota and Firmicutes that contain beneficial taxa. Beneficial genera such as Bacillus and Streptomyces declined, while cultivable Fusarium counts increased. Negative correlations between Fusarium abundance, the bacteria-to-fungi ratio, and the relative abundance of beneficial bacteria further underscore their suppressive role. Guided by these findings, we isolated Bacillus strain NB92, identified as Bacillus siamensis through morphological, biochemical, and 16S rRNA and gyrA gene analyses. NB92 exhibited strong antagonistic activity against the root rot pathogen ( Fusarium sp. St7) via both direct antagonism and volatile organic compound production. Inoculating NB92 into diseased rhizosphere soil boosted Bacillus counts and reduced Fusarium abundance. Moreover, NB92 effectively inhibited the pathogen’s necrotizing ability. B. siamensis NB92 thus represents a promising, sustainable biocontrol agent and contributes to the development of microbiome-based strategies for managing avocado root rot.

Harnessing nature’s arsenal: sustainable plant-based strategies for phytopathogen control

2025-06-18

Gabriel G. Calefi , Nagela Bernadelli Sousa Silva , Bader Y. Alhatlani +2 more | Frontiers in Microbiology

Phytopathogens represent a persistent threat to global agricultural productivity, precipitating yield losses and destabilizing food security. Conventional reliance on synthetic agrochemicals, while effective in phytopathogen suppression, incurs significant economic burdens, … Phytopathogens represent a persistent threat to global agricultural productivity, precipitating yield losses and destabilizing food security. Conventional reliance on synthetic agrochemicals, while effective in phytopathogen suppression, incurs significant economic burdens, drives environmental toxicity, and accelerates the evolution of resistant microbial strains, with collateral risks to ecosystem integrity and public health. This review synthesizes current advancements in harnessing plant- and microorganism-derived extracts, bioactivity-guided fractions, and purified phytochemicals as eco-compatible antimicrobial agents against phytopathogenic bacteria and fungi. Furthermore, we propose a novel framework for standardized prioritization of natural products, integrating efficacy thresholds, phytochemical complexity, and mechanistic specificity to guide scalable antimicrobial discovery. Meta-analysis of published studies reveals a predominant focus on Fusarium spp. as model phytopathogens, with dilution in broth and agar diffusion as the predominant in vitro assays. Quantitative benchmarks for antimicrobial potential were established: bacterial Minimum Inhibitory Concentrations (MICs) ≤ 2.5 mg/mL (crude extracts), ≤0.6 mg/mL (fractions), and ≤64 μg/mL (purified compounds), alongside fungal growth inhibition thresholds &lt;52% (agar dilution assays). These criteria highlight the differential bioactivity of natural product tiers, emphasizing the role of compound purification in potency enhancement. By bridging phytochemical innovation with agronomic applicability, this work positions plant-derived antimicrobials as pivotal tools for sustainable disease management, circumventing agrochemical limitations while advancing One Health-aligned agricultural practices.

Utilization of Microorganisms Streptomyces sp. and Trichoderma sp. in Supporting Sustainable Agriculture

2025-06-18

Tri Mujoko , Penta Suryaminarsih , Bakti Wisnu Wijajani +1 more | Nusantara Science and Technology Proceedings

Utilization of Streptomyces sp and Trichoderma sp microorganisms as biological control agents (BCAs), PGPM, bioremediation, and biofertilization are management alternatives in a sustainable agricultural system and food security. The purpose … Utilization of Streptomyces sp and Trichoderma sp microorganisms as biological control agents (BCAs), PGPM, bioremediation, and biofertilization are management alternatives in a sustainable agricultural system and food security. The purpose of the results compilation of this research is to examine the use of Streptomyces sp and Trichoderma sp. microorganisms in sustainable agricultural practices that support a healthier and environmentally friendly agricultural system. The Streptomyces sp and Trichoderma sp microorganisms used were the results of screening and isolation from tomato and chili fields contaminated with pesticides. Application of Streptomyces sp and Trichoderma sp with various forms of formula was carried out on shallot, tomato, and rice plants on a screenhouse and field scale. The results of this research show that single microorganisms or consortium forms of Streptomyces sp., Trichoderma sp. can control tomato fusarium wilt disease, onion moler disease, fruit flies, and rice pests, increase soil nutrient content, and increase plant production and yield, as well as the continued presence of BCAs on agricultural land.

Growth-Promoting Effects of Ten Soil Bacterial Strains on Maize, Tomato, Cucumber, and Pepper Under Greenhouse Conditions

2025-06-18

Jovana Anđelković , Tatjana Mihajilov Krstev , Ivica Dimkić +3 more | Plants

Beneficial interactions between plants and bacteria are crucial in agricultural practices, as bacteria can improve soil fertility, promote plant growth, and protect plants from pathogens. This study aimed to molecularly … Beneficial interactions between plants and bacteria are crucial in agricultural practices, as bacteria can improve soil fertility, promote plant growth, and protect plants from pathogens. This study aimed to molecularly identify and characterize soil bacterial isolates and evaluate their effect on the growth of maize (Zea mays L.), tomato (Solanum lycopersici L.), cucumber (Cucumis sativus L.), and pepper (Capsicum annuum L.) under greenhouse conditions. Plant growth parameters, including plant height, root length, and fresh (FW) and dry (DW) weights, were measured. Additionally, pigment extraction and element content analysis using leaves were performed. Among the isolates, the most effective strain in the greenhouse experiment was Bacillus safensis SCF6, which significantly enhanced plant height and fresh weight across all tested plants, with the greatest influence observed in maize plant height (439.42 ± 6.42 mm), fresh weight (14.07 ± 0.87 g plant-1 FW), and dry weight (1.43 ± 0.17 g plant-1 DW) compared to the control (364.67 ± 10.33 mm, 9.20 ± 1.16 g plant-1 FW, and 0.92 ± 0.15 g plant-1 DW, respectively). Other strains also demonstrated notable results, with Microbacterium testaceum SCF4, Bacillus mojavensis SCF8, and Pseudomonas putida SCF9 showing the highest plant growth-promoting effects on pepper, tomato, and cucumber, respectively. Pseudomonas putida SCF9 demonstrated strong antifungal activity against Monilinia laxa, with a percentage of mycelial growth inhibition (PGI) of 72.62 ± 2.06%, while Bacillus subtilis SCF1 exhibited effects against Botrytis cinerea (PGI = 69.57 ± 4.35%) and Cercospora sp. (PGI = 63.11 ± 1.12%). The development and application of beneficial bacterial inoculants or their formulated products can contribute to environmentally friendly farming practices and global food security.

Development of biocontrol agents for cotton verticillium wilt using microbiome analysis

2025-06-18

Wanyi Zhang , Jingjing Wang , Peng Wu +7 more | Research Square (Research Square)

<title>Abstract</title> Verticillium wilt is one of the most devastating diseases of cotton. However, effective biocontrol strains are still lacking. The aim of this study is to inform the selection of … <title>Abstract</title> Verticillium wilt is one of the most devastating diseases of cotton. However, effective biocontrol strains are still lacking. The aim of this study is to inform the selection of effective biocontrol strains by comparing the microbiomes of healthy and diseased cotton plants. Our results revealed that <italic>Verticillium dahliae </italic>V991 (V991) is the causal agent of cotton Verticillium wilt, significantly altering the bacterial and fungal communities in the roots, rhizosphere and bulk soil. Compared to the diseased cotton in the V991 inoculation group (D), the healthy cotton in the V991 inoculation group (H) and the control cotton in the V991 non-inoculation group (C) both suppressed <italic>Verticillium</italic> and <italic>Fusarium</italic> and enriched taxa of <italic>Bacilli</italic>, <italic>Clostridia</italic>, <italic>Archacosporales</italic>, <italic>Glomerales</italic>, <italic>unclassified Basidiomycota </italic>and<italic> unclassified Glomeromycota </italic>in the roots, both enriched <italic>Burkholderiales </italic>in the rhizosphere soil, both enriched <italic>Archaeosporales</italic> and <italic>Verrucomicrobiota</italic> in the bulk soil. A total of 20 strains were screened for antagonism to V991, most of them were isolated from the roots of the C group. <italic>Bacillus amyloliquefaciens </italic>M9 (BM), which was screened from the rhizosphere soil, exhibited the strongest antifungal activity, whereas <italic>Bacillus cereus</italic> R19 (BR), which was screened from the root, exhibited weaker antifungal activity. Pot experiments showed that the application of BR and BM (109 CFU/mL) reduced the disease incidence by 44.44% and 33.33%, respectively, compared to the control. Field experiments showed that BR reduced the disease incidence by 88.46%, while BM reduced it by 50.01%. These results demonstrate the effectiveness of comparative microbiome analysis in guiding the selection of highly effective biocontrol strains.

Characterization of Thaumatin-like Gene Family Reveals Group V CaTLPs Drive Anthracnose Resistance in Pepper (Capsicum annuum)

2025-06-18

Hao Wu , Jian Zeng , Cui Mao +7 more | Horticulturae

Pepper anthracnose is a globally devastating fungal disease caused by Colletotrichum spp. In this study, we explored the molecular mechanisms underlying anthracnose resistance in Capsicum annuum by comparing a resistant … Pepper anthracnose is a globally devastating fungal disease caused by Colletotrichum spp. In this study, we explored the molecular mechanisms underlying anthracnose resistance in Capsicum annuum by comparing a resistant variety 225 with a susceptible variety 307. Phenotypic analysis revealed that variety 225 displayed stronger resistance than variety 307. Through comparative transcriptome analysis and weighted gene co-expression network analysis (WGCNA), 17 gene modules were identified, among which the salmon module showed a strong association with resistance in variety 225. Within this module, 18 hub genes—including Ca59V2g00372.1 (CaTLP6), encoding a thaumatin-like protein (TLP)—were significantly upregulated upon infection. A genome-wide analysis identified 31 CaTLP genes in C. annuum, with members of group V (such as CaTLP6) exhibiting induced expression post-inoculation of Colletotrichum scovillei. Subcellular localization analysis indicated that group V CaTLP proteins were associated with the plasma membrane, suggesting a role in pathogen recognition. These findings highlight the significance of CaTLP genes, particularly those in group V, in pepper’s defense against anthracnose caused by C. scovillei and offer promising targets for breeding resistant cultivars.

Serendipita indica: A Plant Elixir for Growth Enhancement and Environmental Stress Resilience

2025-06-18

Sana Saleem | IntechOpen eBooks

Serendipita indica is an endophytic fungus that has received widespread interest as a potential solution for alleviating the effects of climate change on agriculture and minimizing dependency on chemical fertilizers. … Serendipita indica is an endophytic fungus that has received widespread interest as a potential solution for alleviating the effects of climate change on agriculture and minimizing dependency on chemical fertilizers. Furthermore, it has characteristic growth-enhancing and stress-reducing properties, which are becoming an important element of sustainable agricultural techniques. This fungus’ capacity to colonize many plant hosts while improving nutrient absorption, biomass output, and root architecture makes it a viable biofertilizer. Unlike AMF, S. indica may be cultivated relatively easily, allowing for large-scale usage in agricultural techniques. More significantly, S. indica’s superior morphophysiological and biochemical systems help to tolerate abiotic challenges such as drought, salt, temperature changes, and heavy metal toxicity. Furthermore, its capacity to stimulate nutrient absorption, improve root system architecture, and increase biomass output provides a natural alternative to chemical fertilizers, therefore decreasing the negative environmental effects of contemporary farming techniques. These utilize a number of complicated strategies, including the management of phytohormonal pathways, activation of stress-sensitive genes, increase in antioxidant enzyme activity, and maintaining ion homeostasis, all of which improve plant resilience under adverse conditions. This review provides a comprehensive overview of S. indica as a growth promoter and abiotic stress modulator and its potential for transforming modern agriculture and overcoming the challenges posed by global climate change and reducing the dependency on chemical fertilizers.

Carbon Metabolism Modification in Bacillus subtilis for Improving Fengycin Production and Investigating Antifungal Activity of Its Homologous Components

2025-06-17

Dun-Ju Wang , Ming‐Zhu Ding , Zheng-Jie Hou +5 more | ACS Synthetic Biology

As a lipopeptide, fengycin exhibits environmentally friendly, safe, and long-lasting biocontrol efficacy. However, due to its complex structure and the challenges in chemical synthesis, it is primarily produced through biosynthesis. … As a lipopeptide, fengycin exhibits environmentally friendly, safe, and long-lasting biocontrol efficacy. However, due to its complex structure and the challenges in chemical synthesis, it is primarily produced through biosynthesis. This study reports an improvement in fengycin production in Bacillus subtilis by engineering the central carbon metabolic pathway and blocking the carbon overflow pathway. The highest production achieved 1290.31 mg/L, representing a 2.05-fold increase compared to the original strain. Additionally, a coculture system was established in which Corynebacterium glutamicum supplied proline to strain CGF-PA, achieving a further increase in production to 2491.97 mg/L. The fengycin homologues were characterized using IMS-MS and separated by preparative liquid chromatography. The antifungal activities of fengycin homologues were quantitatively evaluated against Fusarium graminearum, Botrytis cinerea, Pyricularia oryzae, and Rhizoctonia solani, and their morphological changes were observed. The study also investigated the differences in antifungal activity among the fengycin variants. Components 4, 5, 6, and 7 exhibited relatively strong antifungal activity, and the various components of fengycin were found to work synergistically.

Identification and functional characterization of plant growth-promoting rhizobacteria enhancing growth and nutritional quality of Sorghum bicolor

2025-06-17

Prema Siva Naga Teja Alapati , Baljeet Singh Saharan | Discover Plants.

2,4-Diacetylphloroglucinol from multi-stress tolerant Pseudomonas guariconensis VDA8: Seed-applied bioprotectant for groundnut (Arachis hypogaea L.) against Aspergillus flavus NCIM 524 for post-harvest preservation

2025-06-17

Raksha A. Kankariya , Ambalal Chaudhari , Navin D. Dandi | Biotechnology Letters

BcDiep1 Effector from Botrytis cinerea Targets Plant LecRK to Induce ROS and Cell Death

2025-06-17

Yunlong Lin , Kedong Xu , Liqin Fan +7 more | Journal of Agricultural and Food Chemistry

A diverse array of lectin receptor kinases (LecRKs) play crucial hub roles in plant adaptation, serving as the primary sensors to perceive, recognize, and promptly respond to a wide range … A diverse array of lectin receptor kinases (LecRKs) play crucial hub roles in plant adaptation, serving as the primary sensors to perceive, recognize, and promptly respond to a wide range of environmental stimuli. Consequently, they are also more vulnerable to targeted attacks by numerous plant pathogens. In this study, BcDIEP1, a secreted death-inducing effector, was identified from Botrytis cinerea during its infection of tomato fruit. BcDIEP1 is an effector associated with pathogenicity but not with growth or stress resistance. Upon secretion, BcDIEP1 selectively interacted with the membrane-anchored receptor LecRK and modulated its phosphorylation status without altering its expression level. This modification of LecRK was correlated with the accumulation of ROS, reactive molecules that can damage cells, leading to cell death. Overall, these findings suggest that BcDIEP1 is a critical effector of B. cinerea pathogenicity, as it disrupts proper signal transduction and induces self-destructive priming within the plant cells.

High-throughput sequencing analysis of community diversity and functional structure of endophytic bacteria in edible vegetable crops: potential implication on plant microbiological quality

2025-06-17

Adekunle Raimi , Rasheed Adeleke | 3 Biotech

Abstract This study evaluated the diversity and functional structure of endophytic bacterial communities residing within four common leafy vegetables: Brassica oleracea, Lactuca sativa, Allium cepa, and Spinacia oleracea , cultivated … Abstract This study evaluated the diversity and functional structure of endophytic bacterial communities residing within four common leafy vegetables: Brassica oleracea, Lactuca sativa, Allium cepa, and Spinacia oleracea , cultivated under organic (OF) and conventional (CF) farming systems. Utilizing high-throughput 16S rRNA gene sequencing and the PICRUSt2 pipeline, the research assessed the influence of plant species, organ (leaf/root), and fertilizer type on these microbial communities. Findings revealed that plant species and organ type significantly shaped endophytic bacterial community composition and diversity. Onion communities were distinct, and roots exhibited higher diversity and richness compared to leaves. Fertilizer type significantly impacted overall bacterial diversity, with CF farms showing higher diversity than OF. Microbial network analysis identified keystone taxa, including network hubs like Serratia and Streptomyces , and module hubs like Solirubrobacter , Corynebacterium , and Mycobacterium . Functional predictions indicated diverse metabolic capabilities, with organ type significantly affecting pathway abundance (leaves enriched in carbohydrate degradation, roots in nutrient metabolism/degradation). OF farms showed higher predicted abundance of some potential virulence pathways, while CF farms had higher abundance of certain biotechnological pathways. Vegetable nutrient content significantly correlated with both bacterial community composition and predicted metabolic pathways. This study highlights the complex interplay between farming practices, plant factors, endophytic microbiomes, and their functional potential, underscoring implications for vegetable microbiological quality and potential human health.