Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics

Fungal Plant Pathogen Control

Works Count: 29350

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This cluster of papers focuses on the evolution, mechanisms, and management of fungicide resistance in plant pathogens, with a particular emphasis on Botrytis cinerea. It covers topics such as molecular mechanisms of resistance, specific fungicide classes (e.g., strobilurins, succinate dehydrogenase inhibitors), and the challenges associated with managing resistance in agricultural settings.

Keywords

Fungicide Resistance; Plant Pathogens; Evolution; Management; Molecular Mechanisms; Phenylamide Fungicides; Strobilurin Fungicides; Succinate Dehydrogenase Inhibitors; Qo Inhibitor Fungicides; Botrytis cinerea

AlternariasectionAlternaria: Species,formae specialesor pathotypes?

2015-08-25

J.H.C. Woudenberg , Michael Seidl , J.Z. Groenewald +4 more

The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains … The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains most of the small-spored Alternaria species with concatenated conidia, including important plant, human and postharvest pathogens. Species within sect. Alternaria have been mostly described based on morphology and / or host-specificity, yet molecular variation between them is minimal. To investigate whether the described morphospecies within sect. Alternaria are supported by molecular data, whole-genome sequencing of nine Alternaria morphospecies supplemented with transcriptome sequencing of 12 Alternaria morphospecies as well as multi-gene sequencing of 168 Alternaria isolates was performed. The assembled genomes ranged in size from 33.3-35.2 Mb within sect. Alternaria and from 32.0-39.1 Mb for all Alternaria genomes. The number of repetitive sequences differed significantly between the different Alternaria genomes; ranging from 1.4-16.5 %. The repeat content within sect. Alternaria was relatively low with only 1.4-2.7 % of repeats. Whole-genome alignments revealed 96.7-98.2 % genome identity between sect. Alternaria isolates, compared to 85.1-89.3 % genome identity for isolates from other sections to the A. alternata reference genome. Similarly, 1.4-2.8 % and 0.8-1.8 % single nucleotide polymorphisms (SNPs) were observed in genomic and transcriptomic sequences, respectively, between isolates from sect. Alternaria, while the percentage of SNPs found in isolates from different sections compared to the A. alternata reference genome was considerably higher; 8.0-10.3 % and 6.1-8.5 %. The topology of a phylogenetic tree based on the whole-genome and transcriptome reads was congruent with multi-gene phylogenies based on commonly used gene regions. Based on the genome and transcriptome data, a set of core proteins was extracted, and primers were designed on two gene regions with a relatively low degree of conservation within sect. Alternaria (96.8 and 97.3 % conservation). Their potential discriminatory power within sect. Alternaria was tested next to nine commonly used gene regions in sect. Alternaria, namely the SSU, LSU, ITS, gapdh, rpb2, tef1, Alt a 1, endoPG and OPA10-2 gene regions. The phylogenies from the two gene regions with a relatively low conservation, KOG1058 and KOG1077, could not distinguish the described morphospecies within sect. Alternaria more effectively than the phylogenies based on the commonly used gene regions for Alternaria. Based on genome and transcriptome comparisons and molecular phylogenies, Alternaria sect. Alternaria consists of only 11 phylogenetic species and one species complex. Thirty-five morphospecies, which cannot be distinguished based on the multi-gene phylogeny, are synonymised under A. alternata. By providing guidelines for the naming and identification of phylogenetic species in Alternaria sect. Alternaria, this manuscript provides a clear and stable species classification in this section.

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Modern Crop Protection Compounds

2007-02-23

Wolfgang Krämer , Ulrich Schirmer

VOLUME 1: HERBICIDES HRAC, Classification of Herbicides and Resistance Development Acetohydroxyacid Synthase Inhibitors (AHAA / ALS) Protoporphyrinogen-IX-Oxidase-Inhibitors Herbicides with Bleaching Properties New Auxin Mimics as Herbicides Herbicides Disturbing the Synthesis … VOLUME 1: HERBICIDES HRAC, Classification of Herbicides and Resistance Development Acetohydroxyacid Synthase Inhibitors (AHAA / ALS) Protoporphyrinogen-IX-Oxidase-Inhibitors Herbicides with Bleaching Properties New Auxin Mimics as Herbicides Herbicides Disturbing the Synthesis of Very Long Fatty Acids Inhibitors of Cellulose Biosynthesis Safeners for Herbicides Genetically Modified Herbicide Resistant Crops Acetyl-CoA Carboxylase Inhibitors Photosynthesis Inhibitors: Regulatory Aspects, Reregistration in Europe, Market Trends and New Products New Aspects of Plant Regulators VOLUME 2: FUNGICIDES FRAC Mode of Action Classification and Resistance Risk of Fungicides Fungicides Acting on Oxidative Phosphorylation Fungicides Acting on Amino Acids and Protein Synthesis Fungicides Acting on Signal Transduction Fungicides Acting on Cell Division Sterol Biosynthesis Inhibitors Carboxylic Acid Amide (CAA) Fungicides Fluopicolide, A New Oomycetes Fungicide Inducing Perturbation of the Cytoskeleton Melanin Synthesis in Cell Wall Fungicides with Unknown Mode of Action Recently Introduced Powdery Mildew Fungicides Newst Aspects of Nucleic Acid Synthesis Inhibitors - Metalaxyl-M Host Defence Inducers VOLUME 3: INSECTICIDES IRAC, Insectile Resistance and Mode of Action Classification of Insecticides Insect Molting and Metamorphosis Chitin Synthesis Midgut - Transgenic Crops Expressing Bacillus Thuringiensis Cry Proteins Metabolic Processes Nervous System New Unknown Mode of Action Insecticides Affecting Calcium Homeostasis

New antibiotics, bleomycin A and B.

1966-09-01

Hitoshi Umezawa , Kazuhiko Maeda , Tsutomu Takeuchi +1 more

Botrytis: Biology, Pathology and Control

2007-01-01

Yigal Elad , B. Williamson , Paul Tudzynski +1 more

Azole fungicides - understanding resistance mechanisms in agricultural fungal pathogens

2015-04-27

Claire Price , Josie E. Parker , Andrew G. S. Warrilow +2 more

Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly … Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice; however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises in order to tackle the problem fully. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pump proteins). © 2015 Society of Chemical Industry.

An analysis of the process of structural change in chromosomes ofDrosophila

1940-05-01

Hermann J. Müller

Identification of a Protein that Binds to the SH3 Region of Abl and Is Similar to Bcr and GAP-rho

1992-08-07

Piera Cicchetti , Bruce J. Mayer , Gerald Thiel +1 more

A Src homology 3 (SH3) region is a sequence of approximately 50 amino acids found in many nonreceptor tyrosine kinases and other proteins. Deletion of the SH3 region from the … A Src homology 3 (SH3) region is a sequence of approximately 50 amino acids found in many nonreceptor tyrosine kinases and other proteins. Deletion of the SH3 region from the protein encoded by the c- abl proto-oncogene activates the protein's transforming capacity, thereby suggesting the participation of the SH3 region in the negative regulation of transformation. A complementary DNA was isolated that encoded a protein, 3BP-1, to which the SH3 region of Abl bound with high specificity and to which SH3 regions from other proteins bound differentially. The sequence of the 3BP-1 protein is similar to that of a COOH-terminal segment of Bcr and to guanosine triphosphatase-activating protein (GAP)-rho, which suggests that it might have GAP activity for Ras-related proteins. The 3BP-1 protein may therefore be a mediator of SH3 function in transformation inhibition and may link tyrosine kinases to Ras-related proteins.

Fungicide-Driven Evolution and Molecular Basis of Multidrug Resistance in Field Populations of the Grey Mould Fungus Botrytis cinerea

2009-12-18

Matthias Kretschmer , Michaela Leroch , Andreas Mosbach +7 more

The grey mould fungus Botrytis cinerea causes losses of commercially important fruits, vegetables and ornamentals worldwide. Fungicide treatments are effective for disease control, but bear the risk of resistance development. … The grey mould fungus Botrytis cinerea causes losses of commercially important fruits, vegetables and ornamentals worldwide. Fungicide treatments are effective for disease control, but bear the risk of resistance development. The major resistance mechanism in fungi is target protein modification resulting in reduced drug binding. Multiple drug resistance (MDR) caused by increased efflux activity is common in human pathogenic microbes, but rarely described for plant pathogens. Annual monitoring for fungicide resistance in field isolates from fungicide-treated vineyards in France and Germany revealed a rapidly increasing appearance of B. cinerea field populations with three distinct MDR phenotypes. All MDR strains showed increased fungicide efflux activity and overexpression of efflux transporter genes. Similar to clinical MDR isolates of Candida yeasts that are due to transcription factor mutations, all MDR1 strains were shown to harbor activating mutations in a transcription factor (Mrr1) that controls the gene encoding ABC transporter AtrB. MDR2 strains had undergone a unique rearrangement in the promoter region of the major facilitator superfamily transporter gene mfsM2, induced by insertion of a retrotransposon-derived sequence. MDR2 strains carrying the same rearranged mfsM2 allele have probably migrated from French to German wine-growing regions. The roles of atrB, mrr1 and mfsM2 were proven by the phenotypes of knock-out and overexpression mutants. As confirmed by sexual crosses, combinations of mrr1 and mfsM2 mutations lead to MDR3 strains with higher broad-spectrum resistance. An MDR3 strain was shown in field experiments to be selected against sensitive strains by fungicide treatments. Our data document for the first time the rising prevalence, spread and molecular basis of MDR populations in a major plant pathogen in agricultural environments. These populations will increase the risk of grey mould rot and hamper the effectiveness of current strategies for fungicide resistance management.

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Imidazolinones

1984-10-01

Dale L. Shaner , Paul C. Anderson , Mark A. Stidham

The imidazolinones, a new chemical class of herbicides, were shown to be uncompetitive inhibitors of acetohydroxyacid synthase from corn. This is the first common enzyme in the biosynthetic pathway for … The imidazolinones, a new chemical class of herbicides, were shown to be uncompetitive inhibitors of acetohydroxyacid synthase from corn. This is the first common enzyme in the biosynthetic pathway for valine, leucine, and isoleucine. The K(i) for the imidazolinones tested ranged from 2 to 12 micromolar. These results may explain the mechanism of action of these new herbicides.

Antimycotic imidazoles. Part 4. Synthesis and antifungal activity of ketoconazole, a new potent orally active broad-spectrum antifungal agent

1979-08-01

Jan Heeres , L. J. J. Backx , J. H. Mostmans +1 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAntimycotic imidazoles. Part 4. Synthesis and antifungal activity of ketoconazole, a new potent orally active broad-spectrum antifungal agentJ. Heeres, L. J. J. Backx, J. H. Mostmans, and … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAntimycotic imidazoles. Part 4. Synthesis and antifungal activity of ketoconazole, a new potent orally active broad-spectrum antifungal agentJ. Heeres, L. J. J. Backx, J. H. Mostmans, and J. Van CutsemCite this: J. Med. Chem. 1979, 22, 8, 1003–1005Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://doi.org/10.1021/jm00194a023RIGHTS & PERMISSIONSArticle Views1425Altmetric-Citations273LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (370 KB) Get e-Alerts Get e-Alerts

Review of strobilurin fungicide chemicals

2007-05-07

H. M. Balba

Abstract Strobilurins are natural products isolated and identified from specific fungi. Natural strobilurins were named in the order of their discovery as strobilurin-A followed by strobilurin-B, C, D etc. Their … Abstract Strobilurins are natural products isolated and identified from specific fungi. Natural strobilurins were named in the order of their discovery as strobilurin-A followed by strobilurin-B, C, D etc. Their discovery opened the door for new chemistry of synthetic fungicides. Applying Quantitative Structural Activity Relationship (QSAR) on the structures of the natural strobilurins, many pesticide companies were able to discover many synthetic analogues that are more efficacious and more stable fungicides. At present there are about eight synthetic strobilurins in the fungicides worldwide market. Some of these products are worldwide registered for use as agrochemical and some are in the process of registration. This class of fungicides is relatively new, as crop protection products and information about them is still fairly scarce. In this review, syntheses and chemistry of natural and synthetic strobilurins are discussed. Also, the mode of action, efficacy, biotic/abiotic degradation, analytical methods, and agricultural uses are discussed. Keywords: Fungicidestrobilurinmushroom natural productselectron transfer inhibitorsquinol oxidation (Qo)qoI fungicidesprotectant fungicidecurative fungicidestranslaminar fungicides. Acknowledgment The author would like to acknowledge the valuable review of Dr. Jeffrey Eberhard and Exponent Inc. for the financial support in the preparation of this review.

Antileishmanial Chalcones: Statistical Design, Synthesis, and Three-Dimensional Quantitative Structure−Activity Relationship Analysis

1998-11-01

Simon Feldbæk Nielsen , S. Brøgger Christensen , Gabriele Cruciani +2 more

A large number of substituted chalcones have been synthesized and tested for antileishmanial and lymphocyte-suppressing activities. A subset of the chalcones was designed by using statistical methods. 3D-QSAR analyses using … A large number of substituted chalcones have been synthesized and tested for antileishmanial and lymphocyte-suppressing activities. A subset of the chalcones was designed by using statistical methods. 3D-QSAR analyses using 67 (antileishmanial activity) and 63 (lymphocyte-suppressing activity) of the compounds for the training sets and 9 compounds as an external validation set were performed by using the GRID/GOLPE methodology. The Smart Region Definition procedure with subsequent region selection as implemented in GOLPE reduced the number of variables to approximately 1300 yielding 3D-QSAR models of high quality (lymphocyte-suppressing model, R2 = 0.90, Q2 = 0.80; antileishmanial model, R2 = 0.73, Q2 = 0.63). The coefficient plots indicate that steric interactions between the chalcones and the target are of major importance for the potencies of the compounds. A comparison of the coefficient plots for the antileishmanial effect and the lymphocyte-suppressing activity discloses significant differences which should make it possible to design chalcones having a high antileishmanial activity without suppressing the proliferation of lymphocytes.

Botrytis cinereavirulence factors: new insights into a necrotrophic and polyphageous pathogen

2007-10-05

Mathias Choquer , Elisabeth Fournier , Caroline Kunz +4 more

Botrytis cinerea is responsible for the gray mold disease on more than 200 host plants. This necrotrophic ascomycete displays the capacity to kill host cells through the production of toxins, … Botrytis cinerea is responsible for the gray mold disease on more than 200 host plants. This necrotrophic ascomycete displays the capacity to kill host cells through the production of toxins, reactive oxygen species and the induction of a plant-produced oxidative burst. Thanks to an arsenal of degrading enzymes, B. cinerea is then able to feed on different plant tissues. Recent molecular approaches, for example on characterizing components of signal transduction pathways, show that this fungus shares conserved virulence factors with other phytopathogens, but also highlight some Botrytis-specific features. The discovery of some first strain-specific virulence factors, together with population data, even suggests a possible host adaptation of the strains. The availability of the genome sequence now stimulates the development of high-throughput functional analysis to decipher the mechanisms involved in the large host range of this species.

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Host-selective toxins produced by the plant pathogenic fungusAlternaria alternata

2012-07-30

Takashi Tsuge , Yoshiaki Harimoto , Kazuya Akimitsu +6 more

Host-selective toxins (HSTs) produced by fungal plant pathogens are generally low-molecular-weight secondary metabolites with a diverse range of structures that function as effectors controlling pathogenicity or virulence in certain plant–pathogen … Host-selective toxins (HSTs) produced by fungal plant pathogens are generally low-molecular-weight secondary metabolites with a diverse range of structures that function as effectors controlling pathogenicity or virulence in certain plant–pathogen interactions. There are now seven known diseases caused by Alternaria alternata in which HSTs are responsible for fungal pathogenesis. The pathogens have been defined as pathotypes of A. alternata because of morphological similarity but pathological differences. Chemical structures of HSTs from six pathotypes have been determined. The role of A. alternataHSTs in pathogenesis has been studied extensively, and discovery of the release of HSTs from germinating conidia prior to penetration aids in understanding the early participation of HSTs to induce susceptibility of host cells by suppressing their defence reactions. Many attempts have been made to find the target sites of A. alternataHSTs, and four cellular components, plasma membrane, mitochondrion, chloroplast and a metabolically important enzyme, have been identified as the primary sites of each HST action, leading to elucidation of the molecular mechanisms of HST sensitivity in host plants. Studies of the molecular genetics of HST production have identified supernumerary chromosomes encoding HST gene clusters and have provided new insights into the evolution of A. alternata pathotypes.

Strobilurins: Evolution of a New Class of Active Substances

1999-05-17

Hubert Sauter , Wölfgang Steglich , Timm Anke

A fungus that grows on pinecones yields a compound with antifungal activity that has become the natural model for a significant innovation in crop protection. Variation and optimization of the … A fungus that grows on pinecones yields a compound with antifungal activity that has become the natural model for a significant innovation in crop protection. Variation and optimization of the lead structure of strobilurin A (1) and selection of derivatives which fulfill all practical requirements, for example, kresoxim-methyl (2), led to an exciting and pan-industrial competition for the development of the strobilurines as a new, highly active, and broadly applicable class of fungicides—a fascinating success story.

Advances in understanding molecular mechanisms of fungicide resistance and molecular detection of resistant genotypes in phytopathogenic fungi

2005-03-08

Zhonghua Ma , Themis J. Michailides

Progress in understanding molecular mechanisms and evolution of resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in phytopathogenic fungi

2010-04-05

Hervé F. Avenot , Themis J. Michailides

Addition of colchicine-tubulin complex to microtubule ends: The mechanism of substoichiometric colchicine poisoning

1977-08-01

Robert L. Margolis , Leslie Wilson

Colchicine blocks microtubule polymerization by an unusual substoichiometric poisoning mechanism. We have investigated the mechanism by which this poisoning occurs with several experimental approaches, and have found that colchicine acts … Colchicine blocks microtubule polymerization by an unusual substoichiometric poisoning mechanism. We have investigated the mechanism by which this poisoning occurs with several experimental approaches, and have found that colchicine acts by addition to microtubule ends as a colchicine-tubulin complex.

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Antifungal activity of chalcones: A mechanistic study using various yeast strains

2008-01-15

Kantcho Lahtchev , Daniela Batovska , St. Parushev +2 more

TOR1 and TOR2 are structurally and functionally similar but not identical phosphatidylinositol kinase homologues in yeast.

1994-01-01

Stephen B. Helliwell , Philipp Wagner , Jeannette Kunz +3 more

The Saccharomyces cerevisiae genes TOR1 and TOR2 were originally identified by mutations that confer resistance to the immunosuppressant rapamycin. TOR2 was previously shown to encode an essential 282-kDa phosphatidylinositol kinase … The Saccharomyces cerevisiae genes TOR1 and TOR2 were originally identified by mutations that confer resistance to the immunosuppressant rapamycin. TOR2 was previously shown to encode an essential 282-kDa phosphatidylinositol kinase (PI kinase) homologue. The TOR1 gene product is also a large (281 kDa) PI kinase homologue, with 67% identity to TOR2. TOR1 is not essential, but a TOR1 TOR2 double disruption uniquely confers a cell cycle (G1) arrest as does exposure to rapamycin; disruption of TOR2 alone is lethal but does not cause a cell cycle arrest. TOR1-TOR2 and TOR2-TOR1 hybrids indicate that carboxy-terminal domains of TOR1 and TOR2 containing a lipid kinase sequence motif are interchangeable and therefore functionally equivalent; the other portions of TOR1 and TOR2 are not interchangeable. The TOR1-1 and TOR2-1 mutations, which confer rapamycin resistance, alter the same potential protein kinase C site in the respective protein's lipid kinase domain. Thus, TOR1 and TOR2 are likely similar but not identical, rapamycin-sensitive PI kinases possibly regulated by phosphorylation. TOR1 and TOR2 may be components of a novel signal transduction pathway controlling progression through G1.

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The rising threat of fungicide resistance in plant pathogenic fungi: Botrytis as a case study

2014-05-27

Matthias Hahn

Botrytis cinerea — history of chemical control and novel fungicides for its management

2000-09-01

Hans-Juergen Rosslenbroich , Dietrich Stuebler

Triazole Fungicides Can Induce Cross-Resistance to Medical Triazoles in Aspergillus fumigatus

2012-03-01

Eveline Snelders , Simone M. T. Camps , Anna Karawajczyk +6 more

Background Azoles play an important role in the management of Aspergillus diseases. Azole resistance is an emerging global problem in Aspergillus fumigatus, and may develop through patient therapy. In addition, … Background Azoles play an important role in the management of Aspergillus diseases. Azole resistance is an emerging global problem in Aspergillus fumigatus, and may develop through patient therapy. In addition, an environmental route of resistance development has been suggested through exposure to 14α-demethylase inhibitors (DMIs). The main resistance mechanism associated with this putative fungicide-driven route is a combination of alterations in the Cyp51A-gene (TR34/L98H). We investigated if TR34/L98H could have developed through exposure to DMIs. Methods and Findings Thirty-one compounds that have been authorized for use as fungicides, herbicides, herbicide safeners and plant growth regulators in the Netherlands between 1970 and 2005, were investigated for cross-resistance to medical triazoles. Furthermore, CYP51-protein homology modeling and molecule alignment studies were performed to identify similarity in molecule structure and docking modes. Five triazole DMIs, propiconazole, bromuconazole, tebuconazole, epoxiconazole and difenoconazole, showed very similar molecule structures to the medical triazoles and adopted similar poses while docking the protein. These DMIs also showed the greatest cross-resistance and, importantly, were authorized for use between 1990 and 1996, directly preceding the recovery of the first clinical TR34/L98H isolate in 1998. Through microsatellite genotyping of TR34/L98H isolates we were able to calculate that the first isolate would have arisen in 1997, confirming the results of the abovementioned experiments. Finally, we performed induction experiments to investigate if TR34/L98H could be induced under laboratory conditions. One isolate evolved from two copies of the tandem repeat to three, indicating that fungicide pressure can indeed result in these genomic changes. Conclusions Our findings support a fungicide-driven route of TR34/L98H development in A. fumigatus. Similar molecule structure characteristics of five triazole DMIs and the three medical triazoles appear the underlying mechanism of cross resistance development. Our findings have major implications for the assessment of health risks associated with the use of triazole DMIs.

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Effects of pre- and post-harvest application of salicylic acid or methyl jasmonate on inducing disease resistance of sweet cherry fruit in storage

2005-02-15

Hongjie Yao , Shiping Tian

Mechanisms influencing the evolution of resistance to Qo inhibitor fungicides

2002-08-12

U. Gisi , Helge Sierotzki , Alison Cook +1 more

Abstract Fungicides inhibiting the mitochondrial respiration of plant pathogens by binding to the cytochrome bc1 enzyme complex (complex III) at the Qo site (Qo inhibitors, QoIs) were first introduced to … Abstract Fungicides inhibiting the mitochondrial respiration of plant pathogens by binding to the cytochrome bc1 enzyme complex (complex III) at the Qo site (Qo inhibitors, QoIs) were first introduced to the market in 1996. After a short time period, isolates resistant to QoIs were detected in field populations of a range of important plant pathogens including Blumeria graminis Speer f sp tritici, Sphaerotheca fuliginea (Schlecht ex Fr) Poll, Plasmopara viticola (Berk & MA Curtis ex de Bary) Berl & de Toni, Pseudoperonospora cubensis (Berk & MA Curtis) Rost, Mycosphaerella fijiensis Morelet and Venturia inaequalis (Cooke) Wint. In most cases, resistance was conferred by a point mutation in the mitochondrial cytochrome b ( cyt b ) gene leading to an amino‐acid change from glycine to alanine at position 143 (G143A), although additional mutations and mechanisms have been claimed in a number of organisms. Transformation of sensitive protoplasts of M fijiensis with a DNA fragment of a resistant M fijiensis isolate containing the mutation yielded fully resistant transformants, demonstrating that the G143A substitution may be the most powerful transversion in the cyt b gene conferring resistance. The G143A substitution is claimed not to affect the activity of the enzyme, suggesting that resistant individuals may not suffer from a significant fitness penalty, as was demonstrated in B graminis f sp tritici . It is not known whether this observation applies also for other pathogen species expressing the G143A substitution. Since fungal cells contain a large number of mitochondria, early mitotic events in the evolution of resistance to QoIs have to be considered, such as mutation frequency (claimed to be higher in mitochondrial than nuclear DNA), intracellular proliferation of mitochondria in the heteroplasmatic cell stage, and cell to cell donation of mutated mitochondria. Since the cyt b gene is located in the mitochondrial genome, inheritance of resistance in filamentous fungi is expected to be non‐Mendelian and, therefore, in most species uniparental. In the isogamous fungus B graminis f sp tritici , crosses of sensitive and resistant parents yielded cleistothecia containing either sensitive or resistant ascospores and the segregation pattern for resistance in the F1 progeny population was 1:1. In the anisogamous fungus V inaequalis , donation of resistance was maternal and the segregation ratio 1:0. In random mating populations, the sex ratio (mating type distribution) is generally assumed to be 1:1. Therefore, the overall proportion of sensitive and resistant individuals in unselected populations is expected to be 1:1. Evolution of resistance to QoIs will depend mainly on early mitotic events; the selection process for resistant mutants in populations exposed to QoI treatments may follow mechanisms similar to those described for resistance controlled by single nuclear genes in other fungicide classes. It will remain important to understand how the mitochondrial nature of QoI resistance and factors such as mutation, recombination, selection and migration might influence the evolution of QoI resistance in different plant pathogens. © 2002 Society of Chemical Industry

Tomato early blight (Alternaria solani): the pathogen, genetics, and breeding for resistance

2006-12-15

Chaerani Chaerani , Roeland E. Voorrips

Differential binding of methyl benzimidazol-2-yl carbamate to fungal tubulin as a mechanism of resistance to this antimitotic agent in mutant strains of Aspergillus nidulans

1977-01-01

L.C. Davidse

The antimitotic compound methyl benzimidazol-2-yl carbamate (MBC) formed a complex in vitro with a protein present in mycelial extracts of fungi. The binding protein of Aspergillus nidulans showed a set … The antimitotic compound methyl benzimidazol-2-yl carbamate (MBC) formed a complex in vitro with a protein present in mycelial extracts of fungi. The binding protein of Aspergillus nidulans showed a set of properties which is unique for tubulin. Binding occurred rapidly at 4 degrees C and was competitively inhibited by oncodazole and colchicine. Other inhibitors of microtubule function such as podophyllotoxin, vinblastine sulfate, melatonin, and griseofulvin did not interfere with binding of MBC. Electrophoretic analysis of partially purified preparations of the binding protein revealed the presence of proteins with similar mobilities as mammalian tubulin monomers. Hence it is concluded that the binding protein is identical with fungal tubulin. The effect of MBC on mycelial growth of mutant strains of A. nidulans was positively correlated with the affinity of the binding sites for this compound. The apparent binding constant for MBC and tubulin from a wild type was estimated at 4.5 X 10(5), from a resistant strain at 3.7 X 10(4), and from a strain with increased sensitivity to MBC at 1.6 X 10(6) liters/mol. Mutants showing resistance and increased sensitivity to MBC are candidates to have alterations in tubulin structure. Affinity of tubulin for MBC is probably a common mechanism of resistance to this compound in fungi. Low affinity of tubulin for MBC is probably a common mechanism of resistance binding constant of 2.5 X 10(3) liters/mol.

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Mechanisms of resistance to fungicides in field strains of Botrytis cinerea

2002-08-12

Pierre Leroux , René Fritz , Danièle Debieu +5 more

Abstract Field strains of Botrytis cinerea Pers ex Fr, the causal agent of grey mould diseases, were collected from French vineyards between 1993 and 2000. Several phenotypes have been characterized … Abstract Field strains of Botrytis cinerea Pers ex Fr, the causal agent of grey mould diseases, were collected from French vineyards between 1993 and 2000. Several phenotypes have been characterized according to the inhibitory effects of fungicides towards germ‐tube elongation and mycelial growth. Two types of benzimidazole‐resistant strains (Ben R1 and Ben R2) could be detected; negative cross‐resistance to phenylcarbamates (eg diethofencarb) was only found in Ben R1. Benzimidazole resistance was related to point mutations at codon 198 (Ben R1) or 200 (Ben R2) of the β‐tubulin gene. Most dicarboximide‐resistant strains were also weakly resistant to aromatic hydrocarbon fungicides (eg dicloran) but remained sensitive to phenylpyrroles (eg fludioxonil). These resistant field strains (Imi R1) contained a single base pair mutation at position 365 in a two‐component histidine kinase gene, probably involved in the fungal osmoregulation. Three anilinopyrimidine‐resistant phenotypes have been identified. In the most resistant one (Ani R1), resistance was restricted to anilinopyrimidines, but no differences were observed in the amino‐acid sequences of cystathionine β‐lyase (the potential target site of these fungicides) from Ani R1 or wild‐type strains. In the two other phenotypes (Ani R2 and Ani R3), resistance extended to various other groups of fungicide, including dicarboximides, phenylpyrroles and sterol biosynthesis inhibitors. This multi‐drug resistance was probably determined by over‐production of ATP‐binding cassette transporters. The hydroxyanilide fenhexamid is a novel botryticide whose primary target site is the 3‐keto reductase involved in sterol C‐4 demethylations. Apart from the multi‐drug‐resistant strain Ani R3, three other fenhexamid‐resistant phenotypes have been recognized. For two of them (Hyd R1 and Hyd R2) fenhexamid‐resistance seemed to result from P450‐mediated detoxification. Reduced sensitivity of the target site could be the putative resistance mechanism operating in the third resistant phenotype (Hyd R3). Increased sensitivity to inhibitors of sterol 14 α‐demethylase recorded in Hyd R1 strains was related to two amino‐acid changes at positions 15 and 105 of this enzyme. © 2002 Society of Chemical Industry

The sections ofAlternaria: formalizing species-group concepts

2013-05-01

Daniel P. Lawrence , Philipp B. Gannibal , Tobin L. Peever +1 more

The systematics of Alternaria and allied genera traditionally has been based on the characteristics of conidia and the sporulation apparatus. This emphasis on morphology in the reconstruction of organismal relationships … The systematics of Alternaria and allied genera traditionally has been based on the characteristics of conidia and the sporulation apparatus. This emphasis on morphology in the reconstruction of organismal relationships has resulted in taxonomic uncertainty and flux for a number of taxa in Alternaria and the related genera Stemphylium, Embellisia, Nimbya and Ulocladium. The present study used a molecular phylogenetic approach for systematic resolution and incorporated extensive taxon sampling (n = 176 species) representing 10 genera and analyses of 10 protein-coding loci. Phylogenetic analyses based on five of these genes revealed eight distinct asexual lineages of Alternaria that cluster as the sister group to the asexual paraphyletic genus Ulocladium, while taxa with known teleomorphs currently circumscribed as Alternaria (the infectoria species-group) cluster among genera that also have representatives with known teleomorphs. This work proposes to elevate the eight well supported asexual lineages of Alternaria to the taxonomic rank of section. Evolutionary relationships among Alternaria and closely related genera are discussed.

A newly identified N-terminal amino acid sequence of human eIF4G binds poly(A)-binding protein and functions in poly(A)-dependent translation

1998-12-15

Hiroaki Imataka

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In vitro antifungal evaluation and structure–activity relationships of a new series of chalcone derivatives and synthetic analogues, with inhibitory properties against polymers of the fungal cell wall

2001-08-01

Silvia N. López , María Victoria Castelli , Susana Zacchino +7 more

In vitro Anthelmintic Properties of Buchholzia coriaceae and Gynandropsis gynandra Extracts

2001-01-01

E. O. Ajaiyeoba , P.A. Onocha , O.T. Olarenwaju

AbstractMethanol extracts from the leaves and stems of Gynandropsis gynandra and Buchholzia coriaceae were investigated for their activity against Fasciola gigantica, Taenia solium and Pheritima pasthuma, respectively. Five concentrations (10–100 … AbstractMethanol extracts from the leaves and stems of Gynandropsis gynandra and Buchholzia coriaceae were investigated for their activity against Fasciola gigantica, Taenia solium and Pheritima pasthuma, respectively. Five concentrations (10–100 mg/ml) of each extract were studied in the bioassay, which involved determination of time of paralysis and time of death of the worms. All the extracts exhibited considerable anthelmintic activities, and the order of sensitivity of the extracts to the worms was P. pasthuma > F. gigantica > T. solium. The most active of the extracts were B. coriaceae and G. gynandra stem methanol extracts. Piperazine citrate (10 mg/ml) and distilled water were included in the assay as standard reference drug and control, respectively.

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A century of fungicide evolution

2005-02-01

P. E. Russell

Up until the 1940s chemical disease control relied upon inorganic chemical preparations, frequently prepared by the user. Key areas of use were horticulture and vegetable production with key targets being … Up until the 1940s chemical disease control relied upon inorganic chemical preparations, frequently prepared by the user. Key areas of use were horticulture and vegetable production with key targets being diseases that caused easily recognized damage. After this era and as the damaging effects of more crop diseases became obvious by the use of chemical control, the crop protection industry expanded rapidly and research to discover new active materials began in earnest. As new areas of chemistry were introduced, each one aiming to offer advantages over the previous ones, chemical families were born with research-based companies frequently adopting patent-busting strategies in order to capitalize on the developing fungicides market. Systemic fungicides offered new opportunities in disease control. The rise in Research and Development (R & D) and the increase in the number and quantity of chemicals being applied led to the introduction of regulation in the 1950s, initially on a voluntary basis, but now strictly controlled by legal obligations. In the 1960s, the market switched from horticulture and vegetables to one in which the main agricultural crops dominated. The cereal market, initially based on barley, moved to the current dominant market of wheat. The costs of R & D have risen dramatically in recent years and have become dominated not by the discovery process per se but by the provision of all the extra data needed to obtain registration. These rising costs happened at a time when markets showed little growth and are currently showing some decline. This has resulted in an industry that is continually striving to cut costs, normally by mergers and take-overs. As a consequence, many plant disease problems are not now being targeted by the industry and special measures have been introduced to ensure adequate disease control is available for these minor markets. Plant disease control will remain a necessity and fungicides will remain as a key factor in such control, although it is predicted that integrated control using chemicals, biological controls and biotechnology approaches will begin to dominate.

Elucidating TOR Signaling and Rapamycin Action: Lessons from Saccharomyces cerevisiae

2002-12-01

José L. Crespo , Michael N. Hall

SUMMARY TOR (target of rapamycin) is a phosphatidylinositol kinase-related protein kinase that controls cell growth in response to nutrients. Rapamycin is an immunosuppressive and anticancer drug that acts by inhibiting … SUMMARY TOR (target of rapamycin) is a phosphatidylinositol kinase-related protein kinase that controls cell growth in response to nutrients. Rapamycin is an immunosuppressive and anticancer drug that acts by inhibiting TOR. The modes of action of TOR and rapamycin are remarkably conserved from S. cerevisiae to humans. The current understanding of TOR and rapamycin is derived largely from studies with S. cerevisiae. In this review, we discuss the contributions made by S. cerevisiae to understanding rapamycin action and TOR function.

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Tyrphostins: tyrosine kinase blockers as novel antiproliferative agents and dissectors of signal transduction

1992-11-01

Alexander Levitzki

Protein tyrosine kinases (PTKs) are members of a growing family of oncoproteins and protooncoproteins that play a pivotal role in normal and abnormal proliferative processes. This hallmark identifies these unique … Protein tyrosine kinases (PTKs) are members of a growing family of oncoproteins and protooncoproteins that play a pivotal role in normal and abnormal proliferative processes. This hallmark identifies these unique proteins as potential targets for antiproliferative therapy. This review discusses the current status of PTK inhibitors, with special emphasis on tyrphostins as antiproliferative agents and as potential drugs for cancers, leukemias, psoriasis, and restenosis as well as other proliferative conditions. The development of tyrphostins as selective signal blockers can be viewed as a first step toward the development of "smart" cocktails as antiproliferative agents. Each of these custom-made cocktails will be aimed at proliferative conditions whose transduction pathways can be characterized by molecular tools. The review also discusses the use of PTK blockers as tools to study signal transduction processes in which protein tyrosine kinases are implicated.— Levitzki, A. Tyrphostines: tyrosine kinase blockers as novel antiproliferative agents and dissectors of signal transduction FASEB J. 6: 3275-3282; 1992.

Fungicide Resistance in Cucurbit Powdery Mildew: Experiences and Challenges

2001-03-01

M. T. McGrath

A Review of Current Knowledge of Resistance Aspects for the Next-Generation Succinate Dehydrogenase Inhibitor Fungicides

2013-04-17

Helge Sierotzki , Gabriel Scalliet

The new broad-spectrum fungicides from the succinate dehydrogenase inhibitor (SDHI) class have been quickly adopted by the market, which may lead to a high selection pressure on various pathogens. Cases … The new broad-spectrum fungicides from the succinate dehydrogenase inhibitor (SDHI) class have been quickly adopted by the market, which may lead to a high selection pressure on various pathogens. Cases of resistance have been observed in 14 fungal pathogens to date and are caused by different mutations in genes encoding the molecular target of SDHIs, which is the mitochondrial succinate dehydrogenase (SDH) enzyme. All of the 17 marketed SDHI fungicides bind to the same ubiquinone binding site of the SDH enzyme. Their primary biochemical mode of action is the blockage of the TCA cycle at the level of succinate to fumarate oxidation, leading to an inhibition of respiration. Homology models and docking simulations explain binding behaviors and some peculiarities of the cross-resistance profiles displayed by different members of this class of fungicides. Furthermore, cross-resistance patterns among SDHIs is complex because many mutations confer full cross resistance while others do not. The nature of the mutations found in pathogen populations varies with species and the selection compound used but cross resistance between all SDHIs has to be assumed at the population level. In most of the cases where resistance has been reported, the frequency is still too low to impact field performance. However, the Fungicide Resistance Action Committee has developed resistance management recommendations for pathogens of different crops in order to reduce the risk for resistance development to this class of fungicides. These recommendations include preventative usage, mixture with partner fungicides active against the current pathogen population, alternation in the mode of action of products used in a spray program, and limitations in the total number of applications per season or per crop.

Alternaria toxins and plant diseases: an overview of origin, occurrence and risks

2009-05-01

Antonio Logrieco , Antonio Moretti , Michele Solfrizzo

The genus Alternaria includes both plant-pathogenic and saprophytic species, which may affect crops in the field or cause harvest and postharvest decay of plant products. The taxonomy of the genus … The genus Alternaria includes both plant-pathogenic and saprophytic species, which may affect crops in the field or cause harvest and postharvest decay of plant products. The taxonomy of the genus Alternaria is not well-defined yet. A polyphasic approach based on morphological features, phylogeny and toxin profiles could be the key to a correct identification at species level and the evaluation of mycotoxin risks associated with fungal contamination. Species of Alternaria are known to produce many metabolites, mostly phytotoxins, which play an important role in the pathogenesis of plants. However, certain species, in particular the most common one A. alternata , are capable of producing several mycotoxins in infected plants and/or in agricultural commodities. The major Alternaria mycotoxins belong to three structural classes: the tetramic acid derivative, tenuazonic acid; the dibenzopyrone derivatives, alternariol, alternariol monomethyl ether and altenuene; and the perylene derivatives, the altertoxins. The toxic effects of the Alternaria toxins have not yet received the same attention as the biological activities of other mycotoxins. However, the Alternaria mycotoxins should not be underestimated since they are produced by several Alternaria species frequently associated with a wide range of diseases in many plants of a high agrifood value. The major problems associated with Alternaria mycotoxin contamination of agricultural products are illustrated by focusing on various crops and their relevant diseases, e.g. black rot of tomato, olive, and carrots; black and grey rot of citrus fruits; black point of small-grain cereals; and Alternaria diseases of apples.

The strobilurin fungicides

2002-05-23

Dave W Bartlett , John M. Clough , Jeremy Godwin +3 more

Abstract Strobilurins are one of the most important classes of agricultural fungicide. Their invention was inspired by a group of fungicidally active natural products. The outstanding benefits they deliver are … Abstract Strobilurins are one of the most important classes of agricultural fungicide. Their invention was inspired by a group of fungicidally active natural products. The outstanding benefits they deliver are currently being utilised in a wide range of crops throughout the world. First launched in 1996, the strobilurins now include the world's biggest selling fungicide, azoxystrobin. By 2002 there will be six strobilurin active ingredients commercially available for agricultural use. This review describes in detail the properties of these active ingredients – their synthesis, biochemical mode of action, biokinetics, fungicidal activity, yield and quality benefits, resistance risk and human and environmental safety. It also describes the clear technical differences that exist between these active ingredients, particularly in the areas of fungicidal activity and biokinetics. © 2002 Society of Chemical Industry

Botrytis cinerea: the cause of grey mould disease

2007-07-23

B. Williamson , Bettina Tudzynski , Paul Tudzynski +1 more

Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is an airborne plant pathogen with a necrotrophic lifestyle attacking over 200 crop hosts worldwide. Although there are fungicides for its control, many classes of … Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is an airborne plant pathogen with a necrotrophic lifestyle attacking over 200 crop hosts worldwide. Although there are fungicides for its control, many classes of fungicides have failed due to its genetic plasticity. It has become an important model for molecular study of necrotrophic fungi.Kingdom: Fungi, phylum: Ascomycota, subphylum: Pezizomycotina, class: Leotiomycetes, order: Helotiales, family: Sclerotiniaceae, genus: Botryotinia.Over 200 mainly dicotyledonous plant species, including important protein, oil, fibre and horticultural crops, are affected in temperate and subtropical regions. It can cause soft rotting of all aerial plant parts, and rotting of vegetables, fruits and flowers post-harvest to produce prolific grey conidiophores and (macro)conidia typical of the disease.B. cinerea produces a range of cell-wall-degrading enzymes, toxins and other low-molecular-weight compounds such as oxalic acid. New evidence suggests that the pathogen triggers the host to induce programmed cell death as an attack strategy. Resistance: There are few examples of robust genetic host resistance, but recent work has identified quantitative trait loci in tomato that offer new approaches for stable polygenic resistance in future.http://www.phi-base.org/query.php, http://www.broad.mit.edu/annotation/genome/botrytis_cinerea/Home.html, http://urgi.versailles.inra.fr/projects/Botrytis/, http://cogeme.ex.ac.uk.

Benzimidazole Fungicides: Mechanism of Action and Biological Impact

1986-09-01

L.C. Davidse

The wide application of benzimidazoles in agriculture and veterinary medi cine as fungicides and anthelminthic drugs, and their experimental use in cancer chemotherapy, has led to intensive research to elucidate … The wide application of benzimidazoles in agriculture and veterinary medi cine as fungicides and anthelminthic drugs, and their experimental use in cancer chemotherapy, has led to intensive research to elucidate their mode of action in detail. These studies show that bioactive benzimidazoles are specific inhibitors of microtubule assembly that act by binding to their heterodimeric subunit, the tubulin molecule. Most of the original literature on antifungal benzimidazoles has already been discussed in a number of reviews (4, 10, 1 3, 14, 19, 52). This chapter, therefore, does not give an extensive review of the complete literature but rather discusses those experiments that made essential contributions to the development of the research area. Much of our knowledge stems from research in fungal cell biology and molecular genetics that uses benzimidazoles as tools to study tubulin structure and the organization and function of microtubules. Rapid progress is being made in the latter areas, which ultimately will lead to a complete characterization of the benzimidazole binding site at the tubulin molecule and its role in microtubule assembly.

The Correlation of Biological Activity of Plant Growth Regulators and Chloromycetin Derivatives with Hammett Constants and Partition Coefficients

1963-09-01

Corwin Hansch , Robert Muir , Toshio Fujita +3 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Correlation of Biological Activity of Plant Growth Regulators and Chloromycetin Derivatives with Hammett Constants and Partition CoefficientsCorwin. Hansch, Robert M. Muir, Toshio. Fujita, Peyton P. Maloney, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Correlation of Biological Activity of Plant Growth Regulators and Chloromycetin Derivatives with Hammett Constants and Partition CoefficientsCorwin. Hansch, Robert M. Muir, Toshio. Fujita, Peyton P. Maloney, Fred. Geiger, and Margaret. StreichCite this: J. Am. Chem. Soc. 1963, 85, 18, 2817–2824Publication Date (Print):September 1, 1963Publication History Published online1 May 2002Published inissue 1 September 1963https://doi.org/10.1021/ja00901a033RIGHTS & PERMISSIONSArticle Views1218Altmetric-Citations444LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Botrytis – the Fungus, the Pathogen and its Management in Agricultural Systems

2015-12-16

Yigal Elad , Melané A. Vivier , Sabine Fillinger

The evolutionary origins of pesticide resistance

2018-07-03

Nichola J. Hawkins , Chris Bass , A. L. Dixon +1 more

Durable crop protection is an essential component of current and future food security. However, the effectiveness of pesticides is threatened by the evolution of resistant pathogens, weeds and insect pests. … Durable crop protection is an essential component of current and future food security. However, the effectiveness of pesticides is threatened by the evolution of resistant pathogens, weeds and insect pests. Pesticides are mostly novel synthetic compounds, and yet target species are often able to evolve resistance soon after a new compound is introduced. Therefore, pesticide resistance provides an interesting case of rapid evolution under strong selective pressures, which can be used to address fundamental questions concerning the evolutionary origins of adaptations to novel conditions. We ask: (i) whether this adaptive potential originates mainly from de novo mutations or from standing variation; (ii) which pre-existing traits could form the basis of resistance adaptations; and (iii) whether recurrence of resistance mechanisms among species results from interbreeding and horizontal gene transfer or from independent parallel evolution. We compare and contrast the three major pesticide groups: insecticides, herbicides and fungicides. Whilst resistance to these three agrochemical classes is to some extent united by the common evolutionary forces at play, there are also important differences. Fungicide resistance appears to evolve, in most cases, by de novo point mutations in the target-site encoding genes; herbicide resistance often evolves through selection of polygenic metabolic resistance from standing variation; and insecticide resistance evolves through a combination of standing variation and de novo mutations in the target site or major metabolic resistance genes. This has practical implications for resistance risk assessment and management, and lessons learnt from pesticide resistance should be applied in the deployment of novel, non-chemical pest-control methods.

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Design, synthesis, and DNA binding properties of bifunctional intercalators. Comparison of polymethylene and diphenyl ether chains connecting phenanthridine

1985-04-01

Michael Cory , David D. McKee , J. Kagan +2 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign, synthesis, and DNA binding properties of bifunctional intercalators. Comparison of polymethylene and diphenyl ether chains connecting phenanthridineM. Cory, David D. McKee, J. Kagan, Henry D. W., … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign, synthesis, and DNA binding properties of bifunctional intercalators. Comparison of polymethylene and diphenyl ether chains connecting phenanthridineM. Cory, David D. McKee, J. Kagan, Henry D. W., and J. Allen MillerCite this: J. Am. Chem. Soc. 1985, 107, 8, 2528–2536Publication Date (Print):April 1, 1985Publication History Published online1 May 2002Published inissue 1 April 1985https://pubs.acs.org/doi/10.1021/ja00294a054https://doi.org/10.1021/ja00294a054research-articleACS PublicationsRequest reuse permissionsArticle Views767Altmetric-Citations396LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Habilitationsschrift

2009-04-24

Resistance of Alternaria spp. Causing Strawberry Black Spot to Boscalid in China

2025-06-24

Tao Li , Wenbin Yu , Feng Ji +4 more | Plants

Strawberry black spot, caused by Alternaria spp., is an emerging disease that threatens both leaves and fruits during strawberry growth and postharvest storage. This study investigated the boscalid sensitivity of … Strawberry black spot, caused by Alternaria spp., is an emerging disease that threatens both leaves and fruits during strawberry growth and postharvest storage. This study investigated the boscalid sensitivity of 49 Alternaria isolates collected from symptomatic strawberry leaves. Boscalid has been widely used to control diseases in strawberry in China for several years. The EC50 values for the tested isolates ranged from 0.0884 to 266.3289 µg/mL, indicating that most isolates exhibited varying levels of resistance to boscalid based on resistance ratio values. A substitution of SDHC-H134R was detected from most high-resistance isolates. Fitness cost assessment revealed that highly resistant isolates had a reduced conidial germination rate; however, their mycelial growth and conidia production were increased. No significant virulence deficiency was observed, suggesting low fitness cost in resistant isolates. Furthermore, the highly resistant isolates exhibited positive cross-resistance to fluopyram and fluxapyroxad. Molecular docking analysis revealed that the SDHC-H134R mutation reduced the binding affinity between boscalid and mitochondrial complex II. These findings suggest that resistance management strategies, such as fungicide rotation or combinations of fungicides with different action modes, should be implemented to control strawberry diseases, minimizing the development of fungicide resistance and improving overall disease control efficacy.

Transcriptome Analysis Reveals the Response Mechanism of Grape Leaves to Botrytis cinerea

2025-06-24

Chengnan Li , Yulei Zhao , Denghui Ma +3 more | Plant Molecular Biology Reporter

Kynurenine monooxygenase BcKMOL: a key regulator of growth, pathogenicity, and disease control in Botrytis cinerea

2025-06-24

Li Bai , Xiaoying Liu , Jinping Zang +5 more | Frontiers in Microbiology

Kynurenine monooxygenase, a vital rate-limiting enzyme in the kynurenine pathway metabolic branch, has shown promise as a drug target for treating human neurodegenerative diseases. However, the role of kynurenine monooxygenase … Kynurenine monooxygenase, a vital rate-limiting enzyme in the kynurenine pathway metabolic branch, has shown promise as a drug target for treating human neurodegenerative diseases. However, the role of kynurenine monooxygenase in plant pathogens and its potential as a molecular target have received limited attention. In this study, we identified a novel kynurenine monooxygenase gene, BcKMOL , in Botrytis cinerea . By generating mutants of this gene, it was found that the deletion of BcKMOL affected the changes of key metabolites in the kynurenine pathway in vivo , and the △ BcKMOL mutant exhibits reduced growth and fails to produce sclerotia. Additionally, changes were observed in the morphology of mycelium cells and spores, and the mutant’s pathogenicity was weakened. These findings indicate that BcKMOL positively regulates the growth, development, and pathogenic processes of B. cinerea . Furthermore, we screened two antibacterial peptides, CAMPQ3966 and CAMPQ4589, that target BcKMOL using MEGADOCK, HDOCK, and AlphaFold3. Both peptides effectively inhibited the pathogenicity of B. cinerea . These findings provide the foundation for developing novel drug targets for controlling gray mold.

Enantioseparation and Stereoselective Fungicidal Activity of Fenoxanil Stereoisomer against Magnaporthe oryzae

2025-06-23

Wei Zhao , Zhiqiang Lu , Shiyuan Yang +3 more | Journal of Agricultural and Food Chemistry

Fenoxanil is a chiral amide fungicide mixture that comprises two enantiomeric pairs. This study describes the baseline separation of fenoxanil stereoisomers via ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry … Fenoxanil is a chiral amide fungicide mixture that comprises two enantiomeric pairs. This study describes the baseline separation of fenoxanil stereoisomers via ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry using a Lux Cellulose-3 chiral column. The absolute configuration of the fenoxanil stereoisomers was confirmed via electronic circular dichroism. The elution sequence of the four fenoxanil stereoisomers was (1R,2R)-(+)-, (1R,2S)-(-)-, (1S,2R)-(+)-, and (1S,2S)-(-)-fenoxanil. The average recoveries of the fenoxanil stereoisomers in brown rice, rice husk, and rice plant ranged from 70.1% to 109.4%, with intraday and interday relative standard deviations of <9.4 and <11.7%, and a limit of quantitation of 0.05 mg/kg. Bioactivity assays against Magnaporthe oryzae revealed that (1R,2R)-(+)-fenoxanil is a highly bioactive stereoisomer, with 3.7- and 21.7-times higher bioactivity than the mix-fenoxanil (four stereoisomer mixture) and (1S,2S)-(-)-fenoxanil, respectively. The contribution rate of (1R,2R)-(+)-fenoxanil to the total bioactivity was 96.6%. The chiral carbon atom linked to the cyano group was identified as being crucial to the bioactivity of fenoxanil, with (1R,2RS)-fenoxanil exhibiting 2.2 times higher activity than the stereoisomer mixture. The findings of the study provide a basis for the reduction of fenoxanil use by using a single high-efficiency isomer, which is important for food safety and environmental protection.

Origins of new modes of action for fungicides, herbicides and insecticides: a review and analysis

2025-06-18

Thomas C. Sparks , Beth A. Lorsbach , Janine M. Sparks +1 more | Pest Management Science

Abstract New modes of action (MoAs) can be a key driver for the discovery of new crop protection compounds, facilitating resistance management programs and providing the basis for compounds with … Abstract New modes of action (MoAs) can be a key driver for the discovery of new crop protection compounds, facilitating resistance management programs and providing the basis for compounds with improved toxicological and environmental attributes. There are numerous approaches to the discovery of new crop protection compounds that can be grouped broadly into competitor inspired, next generation, natural products, and bioactive hypothesis. The latter group, bioactive hypothesis, is itself composed of an array of approaches that include exploring novel areas of chemistry, testing chemistries from other therapeutic areas, bioactive scaffolds, internal libraries, and many more. In theory, all of these approaches can lead to new crop protection compounds with new MoAs. Herein, we provide an analysis of the approaches that have been used to discover fungicides, herbicides, and insecticides with different MoAs. The goal of this analysis is to identify the approaches based on available data which are most likely to yield pest management compounds with new MoAs. © 2025 Society of Chemical Industry.

The Impact of Essential Oils Derived from Citrus Species to Control Botrytis cinerea and Their Potential Physiological Actions

2025-06-17

SILVIA LEITE DE CAMPOS , Javier Espinoza , J.M. Fuentes +7 more | Plants

Botrytis cinerea is one of the phytopathogenic fungi of the greatest economic importance worldwide. Essential oils (EOs) have been proposed as a sustainable alternative to reduce the growth of phytopathogenic … Botrytis cinerea is one of the phytopathogenic fungi of the greatest economic importance worldwide. Essential oils (EOs) have been proposed as a sustainable alternative to reduce the growth of phytopathogenic fungi. Nevertheless, few studies exist about its mechanisms of action. This study evaluated the antifungal activity of EOs from Citrus reticulata, Citrus limon, Citrus sinensis, and Citrus paradisi peels and their encapsulation inside solid lipid nanoparticles (SLNs). Accordingly, Citrus EOs were mainly constituted by monoterpene hydrocarbons, where limonene was the most abundant in all EOs. C. reticulata and C. limon EOs reduced the mycelial growth at above 54% after 96 h. The other EOs did not significantly impact the phytopathogen. C. reticulata EO increased the hyphae damage by 40%, but the spore germination was reduced by only 8.34%. It also significantly increased the pH, the electrical conductivity, and the release of intracellular absorbing material and soluble proteins in B. cinerea cultures. Contrary, the esterase, mitochondrial, and succinate dehydrogenase activities decreased at above 50%. C. reticulata EO into SLN reduced the mycelial growth of B. cinerea by 90-97%. These results show that the EO of C. reticulata alters the physiological and metabolic activities of B. cinerea to reduce its growth.

Transcriptomic analysis of genotypes derived from Rosa wichurana unveils molecular mechanisms associated with quantitative resistance to Diplocarpon rosae

2025-06-17

L. Lambelin , Tatiana Thouroude , Julien Jeauffre +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Black spot disease, caused by the hemibiotrophic fungus Diplocarpon rosae , is a major foliar disease of garden roses. Resistant cultivars offer an alternative to fungicides, but the genetic … Abstract Black spot disease, caused by the hemibiotrophic fungus Diplocarpon rosae , is a major foliar disease of garden roses. Resistant cultivars offer an alternative to fungicides, but the genetic basis of resistance is not well known. Understanding these mechanisms is essential for the effective and durable deployment of resistant cultivars. A hybrid of Rosa wichurana (RW) exhibits quantitative resistance to black spot. Analysis of an F1 progeny from a cross between RW and the susceptible cultivar Rosa chinensis ‘Old Blush’ showed that RW’s resistance mainly involves two Quantitative Trait Loci (QTLs), on linkage groups 3 (B3) and 5 (B5). This study aimed to better characterize the molecular mechanisms underlying these QTLs. RNA sequencing was performed on inoculated and non-inoculated samples of RW and four F1 genotypes with different QTL combinations, at 0, 3, and 5 days post-inoculation (dpi). The comparison of inoculated and non-inoculated samples revealed that most genes were differentially expressed at 3 dpi. For all the genotypes, we observed shifts in expression of genes involved in plant defense, as well as genes participating in hormonal pathways and calcium-mediated signaling. Genotypes harboring QTL B3 showed “classic” defense responses involving pathogen recognition, signaling, ROS production, callose deposition, and localized cell death. In contrast, QTL B5 was associated with few shared DEGs, making it harder to define its role. The quantitative nature of RW’s resistance may result in this complex regulation of gene expression.

IN-SILICO AND IN-VITRO EVALUATION OF FUNGICIDAL ACTIVITY OF AMINOMETHYLATED DERIVATIVES OF 1,2,4-TRIAZOLE, 2-NAPHTHOL AND INDOLE

2025-06-16

Nail S. Akhmadiev , N. F. Galimzyanova , E.M. Galimova +2 more | Izvestia Ufimskogo Nauchnogo Tsentra RAN

The interaction of the reagent N,N,Nʹ,Nʹ-tetramethyldiaminomethane with 1,2,4-triazole and 2-naphthol yielded compounds containing a monoaminomethylated fragment. Subsequent interaction of the aminomethylation products with methyl iodide led to the formation of … The interaction of the reagent N,N,Nʹ,Nʹ-tetramethyldiaminomethane with 1,2,4-triazole and 2-naphthol yielded compounds containing a monoaminomethylated fragment. Subsequent interaction of the aminomethylation products with methyl iodide led to the formation of quaternized salts. Using the molecular docking method, reasonable assumptions were made about the complementarity of the obtained series of compounds with the active center of lanosterol-14α-demethylase CYP51 from Saccharomyces cerevisiae. Primary screening of monoaminomethylated derivatives for fungicidal activity against the phytopathogenic fungi Bipolaris sorokiniana, Fusarium oxysporum and Rhizoctonia solani showed that compounds containing a substituent in the form of a quaternized form of nitrogen have greater fungicidal activity.

Flavonoid compounds as a way to identify sources of carrot resistance to Alternaria leaf blight

2025-06-01

Marie Louisa Ramaroson , Claude Koutouan , Angélina El Ghaziri +7 more | Molecular Breeding

Abstract Breeding varieties that are highly resistant to Alternaria leaf blight is crucial to enable carrot growers to drastically reduce their use of synthetic fungicides. Some sources of resistance have … Abstract Breeding varieties that are highly resistant to Alternaria leaf blight is crucial to enable carrot growers to drastically reduce their use of synthetic fungicides. Some sources of resistance have been identified in recent years, but in limited number and the genetic control as well as the screening for resistance remain complex and tedious. Flavonoid compounds have been reported to be involved in plant resistance to biotic or abiotic stresses. Their level of variation could therefore be a way of assisting screening activities for resistance. The aim of the study is to validate this link throughout the carrot growth cycle, in various environments and across a wide genetic diversity. A kinetic study showed that three flavonoid compounds are differentially accumulated between resistant and susceptible accessions as early as the 2-leaf stage and all along the plant development. Moreover, this differential is maintained throughout the potential infectious process in different environments. The analysis of a large range of accessions representing a very wide diversity of geographical origins, genetic structures, breeders and varietal types validates the link between resistance and the content in flavonoid compounds. These results open up extremely interesting prospects for the development of a marker-assisted early selection tool that would facilitate the screening and introgression of resistances into elite material, a complex task due to the polygenic control of resistance and biennial nature of the crop.

Advancing Control of Stemphylium vesicarium on Asparagus Fern Using TOMCAST and New Fungicides

2025-06-01

John Rocliffe Spafford , M. K. Hausbeck | Crop Protection

New point mutations in osmosensing two-component histidine kinase gene associated with iprodione resistance in Monilinia fructicola field isolates from China

2025-06-01

Long Qian , Yang Guo , Ming Yi +7 more | Pesticide Biochemistry and Physiology

Design, synthesis, antifungal evaluation and mechanism study of novel thiazolamide derivatives containing a diarylamine scaffold

2025-06-01

Zhongzhong Yan , Qianqian Han , Haowei Wang +7 more | Pesticide Biochemistry and Physiology

Synergistic effect and water dispersible tablet of propamidine and flusilazole against Botrytis cinerea

2025-05-28

Yong Wang , Yonghui Qiao , Guanyou Xu +4 more | Plant Disease

Propamidine exhibited potent fungicidal activity against Botrytis cinerea, and it has no cross resistance with other commercial fungicides. In this work, propamidine and flusilazole were combined to obtain synergistic effects … Propamidine exhibited potent fungicidal activity against Botrytis cinerea, and it has no cross resistance with other commercial fungicides. In this work, propamidine and flusilazole were combined to obtain synergistic effects against gray mold and delay the development of fungicide resistance. The results suggested that the optimal synergistic ratio (SR) of propamidine to flusilazole was 4:1, with a SR of 2.07. Based on this ratio, the optimized formulation of 50% Pro · Flu (4:1) water dispersible tablet (WDT) comprised 40% propamidine, 10% flusilazole, 4% BSA, 8% benzalkonium chloride, 7% glucose, and sufficient silica to achieve a total of 100%. The WDT met the standards for active ingredient (a.i.) content, suspension rate, disintegration time, heat stability, and other relevant indicators. Importantly, the WDT at 200 μg/mL displayed over 80% preventive and curative activity, which was comparable to that of propamidine or flusilazole at 400 μg/mL in controlling gray mold. In field trials, the efficacy of WDT was significantly higher than that of the single fungicide at the equivalent dosage. This formulation could dramatically reduce the dosage of flusilazole, alleviate the pressure of screening pathogenic fungi and the risk of plant pathogens developing resistance to fungicides, ultimately decreasing the total use of pesticides and environmental pollution.

Fungicide Resistance Management

2025-05-28

Ashutosh Bhaik , Mamadou Mboup , Jean‐Luc Genet +1 more | CRC Press eBooks

Discovery of novel 1,5‐diaryl‐3‐trifluoropyrazoles as antifungal pesticides for crop protection

2025-05-28

Yihui Ma , Dangwei Yang , Guangyu Qin +3 more | Pest Management Science

Abstract BACKGROUND Plant diseases caused by phytopathogenic fungi continue to threaten global food security, driving the urgent need for discovery of antifungal agrochemicals with novel modes of action. The motif … Abstract BACKGROUND Plant diseases caused by phytopathogenic fungi continue to threaten global food security, driving the urgent need for discovery of antifungal agrochemicals with novel modes of action. The motif of 1,5‐diaryl‐3‐trifluoropyrazole was found to be associated with potential antifungal effect and HNNK‐5 was such an agrochemical being developed in our lab with moderate potency. This study took HNNK‐5 as the parent compound for lead optimization to discovery novel fungicides. RESULT To further explore the antifungal potential of this class of compounds, a series of analogues of HNNK‐5 was designed and prepared. Among them, compound 7 was identified as the most potent member with much improved activity over the lead compound. Compound 7 almost completely inhibited the growth of all the tested fungal pathogens at 50 μg/mL with an EC 50 range of 6.2–11.5 μg/mL, multiple‐fold less potent than the positive control azoxystrobin. Scanning electronic microscope (SEM) observation and fatty acid analysis showed that compound 7 treatment caused morphological changes and altered the amount of fatty acids of Fusarium oxysporum . Furthermore, compound 7 at higher application rates showed pronounced controlling effects against peanut root rot disease caused by Fusarium oxysporum in field study, similar to those of positive control azoxystrobin. CONCLUSION This study indicated that the characteristic structure of 1,5‐diaryl‐3‐trifluoropyrazole could be employed as a potential skeleton for antifungal pesticides development and provided compound 7 as a promising pesticide candidate for further development. © 2025 Society of Chemical Industry.

Morphological and Molecular Characterization of a New Section and Two New Species of Alternaria from Iran

2025-05-28

Abdollah Ahmadpour , Youbert Ghosta , Zahra Alavi +3 more | Life

Alternaria is a large genus of fungi comprising approximately 400 species, currently classified into 29 sections. These fungi exhibit a cosmopolitan distribution, thriving in both natural and human-impacted environments with … Alternaria is a large genus of fungi comprising approximately 400 species, currently classified into 29 sections. These fungi exhibit a cosmopolitan distribution, thriving in both natural and human-impacted environments with saprophytic, endophytic, and parasitic lifestyles. As part of our ongoing studies on fungi associated with wetland plants in the families Cyperaceae and Juncaceae across various regions of Iran, we isolated 21 fungal strains displaying morphological traits of Alternaria. Multigene phylogenetic analysis and morphological examination of eight selected strains confirmed their placement within Alternaria with strong support. These isolates formed a basal clade distinct from the 29 previously recognized sections and six monotypic lineages, leading to the establishment of a new section, Alternaria section Iraniana, to accommodate them. Furthermore, two monophyletic lineages within this section were identified, representing two new species, A. avrinica and A. iraniana, which are described and illustrated in this study. The new section is distinguished by long, semi-macronematous to macronematous conidiophores with multiple geniculate and sympodial proliferations, as well as solitary, non-beaked conidia that have only transverse eu-septa to pseudo-septa. The newly described species are differentiated based on conidiophore and conidial characteristics and nucleotide sequence comparisons of genomic regions. These results contribute to a better understanding of the distribution and host range of Alternaria species, while highlighting the importance of ongoing research into fungal taxonomy and biodiversity in Iran, a region rich in potential for the discovery of new fungal species.

Development and validation of a standard area diagram (SAD) set for assessing Alternaria black spot severity in pecan leaves

2025-05-27

María Coronel , Franca Denise Carrasco , Ruth Mariela Kaen +5 more

<title>Abstract</title> Pecan (<italic>Carya illinoinensis</italic>) cultivation is expanding in Argentina, with Catamarca Province emerging as a significant production region. However, fungal diseases such as Alternaria black spot (ABS), caused by <italic>Alternaria</italic> … <title>Abstract</title> Pecan (<italic>Carya illinoinensis</italic>) cultivation is expanding in Argentina, with Catamarca Province emerging as a significant production region. However, fungal diseases such as Alternaria black spot (ABS), caused by <italic>Alternaria</italic> spp., pose an increasing threat to crop yield and health. Considering that disease quantification is crucial for epidemiological studies and management, this study aimed to design and validate a standard area diagram (SAD) set to improve the visual estimation of ABS severity on pecan leaves. Using 255 diseased leaves, an eight-image SAD set with severity levels that linearly ranged from 2.2–88.9% was designed. Thirty-four raters participated in the validation process using the online platform <italic>TraineR2</italic> in two phases: unaided and aided assessments. The use of the SAD set significantly improved accuracy metrics. Lin’s concordance correlation coefficient (CCC) increased from 0.93 to 0.97, while precision (r) rose from 0.92 to 0.97. Additionally, inter-rater reliability, measured using the intraclass correlation coefficient (ICC), improved from 0.86 to 0.93. This study demonstrates the effectiveness of the SAD set tool in enhancing the accuracy and consistency of ABS severity estimations, highlighting its potential as a practical resource for pecan producers and researchers.

Functional Outlook of Penicillium digitatum PdMFS6 Transporter to Elucidate Its Role in Fungicide Resistance and Virulence

2025-05-26

Paloma Sánchez‐Torres

A novel Penicillium digitatum MFS transporter, PdMFS6 (PDIP_42530), was recognized, and its function was studied to explain its relevance in the simultaneous development of resistance to different fungicide spectrums. No … A novel Penicillium digitatum MFS transporter, PdMFS6 (PDIP_42530), was recognized, and its function was studied to explain its relevance in the simultaneous development of resistance to different fungicide spectrums. No changes were detected after application of chemical fungicides in mutants with the deleted gene, but chemical susceptibility was severely impaired in overexpressing strains, that became persistent to different chemicals. Furthermore, P. digitatum deleted transformants showed less fungal virulence appraise upon citrus infection stored at 20 °C. In strains derived from Pd149-P. digitatum with low virulence and overexpressing PdMFS6, the signs of the disease were more evident. In addition, evaluation of gene transcription showed an increase in PdMFS6 gene expression over time in all P. digitatum strains tested. It is noteworthy that during citrus fruit infection, the wild-type Pd1 strain displayed an augmented level of transcription, indicating that this transporter plays a role in infectivity. The fungal transporter PdMFS6 could contribute to the susceptibility to chemicals commonly used in postharvest treatments, as well as to rise the virulence of P. digitatum during fruit infection.

Citral‐based amide derivatives improve the antifungal activity of Kresoxim‐methyl against <scp>Rhizoctonia solani</scp>

2025-05-26

Xiaoyi Pan , Guoxiang Liao , Hongfei Li +7 more

Abstract BACKGROUND Rhizoctonia solani , the fungal pathogen causing rice sheath blight, threatens global food security. Prolonged use of Kresoxim‐methyl (KM), a common fungicide, has led to resistance and reduced … Abstract BACKGROUND Rhizoctonia solani , the fungal pathogen causing rice sheath blight, threatens global food security. Prolonged use of Kresoxim‐methyl (KM), a common fungicide, has led to resistance and reduced effectiveness. This study investigates the synergistic effects of citral‐based amide derivatives with KM and explains the underlying mechanisms. RESULT Among the tested derivatives, compound d25 exhibited the most pronounced synergistic effect, achieving a peak synergistic ratio (SR = 2.66 ± 0.67) at a molar ratio of 25% in the mixture. At a molar ratio of 10%, the mixture (Mix) demonstrated significant antifungal activity both in vitro and in vivo , effectively reducing mycelial dry weight and enhancing rice leaf protection. Mechanistic studies revealed that Mix disrupted the tricarboxylic acid (TCA) cycle, thereby inhibiting energy metabolism. Additionally, d25 interfered with arachidonic acid metabolism, impairing cell membrane repair mechanisms and enhancing the fungicidal efficacy of KM. Toxicity assessments revealed that d25 exhibited minimal cytotoxicity against human cell lines and low acute toxicity toward Apis mellifera L. and zebrafish. CONCLUSION The findings elucidate the synergistic mechanisms of d25 and Mix, underscoring their potential as effective fungicide synergists. This study establishes a robust theoretical and practical foundation for enhancing the efficacy of chemical control strategies against R. solani , providing new insights into the development of safe and efficient fungicide formulations. © 2025 Society of Chemical Industry.

Fungicide Resistance and Pathogenicity of Monilinia laxa Isolates from Prunus Species in Türkiye

2025-05-26

Hamza Şenyurt , Dudu Demir , Cafer Eken

Spatial Distribution of Deudorix livia and Associated Predatory Insects on Pomegranate Manfaloty Cultivar at Assiut Governorate

2025-05-26

Ahmed M. M. Ahmed , F. A. Abdel-Galil , Sara E. Mousa +4 more | Egyptian Academic Journal of Biological Sciences

Editorial: Molecular interactions and control strategies for Botrytis cinerea in crop production

2025-05-26

Paulo Canessa , Simone Ferrari

Underutilized pulses: Quality evaluation and value addition

2025-05-24

E. Tamilselvi , G Sashidevi , S. Arokiamary +3 more

Underutilized pulses have significant potential for enhancing food and nutritional security while contributing to agricultural development. Quality assessment and value addition are important to promote underutilized pulses in an effective … Underutilized pulses have significant potential for enhancing food and nutritional security while contributing to agricultural development. Quality assessment and value addition are important to promote underutilized pulses in an effective way. This study evaluated the physical, cooking, nutritional and phytochemical profiles of moth bean and rice bean. The bulk density of moth bean and rice beans were found to be 892 kg/m3 and 846 kg/m3, respectively. The cooking time for unroasted moth bean was 60 min and for roasted moth bean it was nearly half the time reduced (≈35 min). Roasting of pulses had significant reduction of cooking time. Both moth bean and rice bean exhibited a favorable nutritional profile, with protein contents of 20.63 g/100g and 19.28 g/100g respectively. The fat content was less than 1 g in both pulses while fiber content was at 5.6 % for moth bean and 4.32 % for the rice bean. The phytochemicals such as phytic acid, tannins and saponins were present in both pulses. Moth bean and rice bean are highly suitable for the preparation of regular pulse based recipes and products with commercial value as well. Nutrimix prepared using underutilized pulses were highly acceptable by semi-trained panel of sensory evaluation with a shelf life of two months and is suitable for commercial production.

Pre and postharvest application of phenylalanine reduces Botrytis cinerea infection in strawberries during storage

2025-05-23

Coline Pons , Tangui Le Noan , Sandrine Laurent +3 more

Natural Furan-Carboxylic Acid (HHCA) and Its Derivatives: Synthesis, Characterization, Bioevaluation, and Structure–Activity Relationships as Potential Fungicidal Agents

2025-05-23

Lirong Guo , Hexiang Wang , Fuqiang Zheng +7 more

The exploration of natural products as lead scaffolds continues to serve as a valuable strategy for the development of novel antifungal agents. In this investigation, we focused on the natural … The exploration of natural products as lead scaffolds continues to serve as a valuable strategy for the development of novel antifungal agents. In this investigation, we focused on the natural furanoid compound 2-heptyl-5-hexylfuran-3-carboxylic acid (HHCA) and designed and synthesized four distinct series of multisubstituted furan carboxylic acid derivatives. Comprehensive structural characterization and biological evaluation were performed for all 48 compounds. In vitro antifungal screening against eight prevalent plant pathogens revealed that some of these derivatives exhibited significant inhibitory effects against Botrytis cinerea and Sclerotinia sclerotiorum. Structure-activity relationship analysis demonstrated that peptide-containing derivatives showed superior antifungal potency compared with their hydrazide, amide, and ester counterparts. The most promising candidate compound 5g was further evaluated for its in vivo efficacy against two plant pathogens, S. sclerotiorum and B. cinerea, indicating potent antifungal activity with EC50 values of 17.14 μg/mL and 19.63 μg/mL, respectively. Notably, these values were significantly lower than those of the natural product HHCA with an enhanced antifungal potency. These findings highlight the practical potential of compound 5g as a novel antifungal agent for agricultural applications. Mechanistic investigations employing microscopic analysis, molecular docking simulations, and density functional theory (DFT) calculations provided insights into the putative mode of action of 5g, particularly regarding its interaction with succinate dehydrogenase (SDH). These findings establish a foundation for the rational development of HHCA-derived furan derivatives as novel SDH-targeting fungicidal agents.

Optimizing Fungicide Application Timing to Control Olive Peacock Eye Disease: Impact on Current and Succeeding Growing Seasons

2025-05-22

David Ygzao , D. Shtienberg , ‪David Ezra‬‏

We recently provided new insights into the etiology of Venturia oleaginea, the causal agent of peacock eye disease in olive. We identified two distinct periods of infection events during each … We recently provided new insights into the etiology of Venturia oleaginea, the causal agent of peacock eye disease in olive. We identified two distinct periods of infection events during each growing season: the first in autumn and the second in spring. In addition, we reported the occurrence of two episodes of disease development: the first at the end of autumn/beginning of winter, and the second in the spring and early summer. The main goal of the current study was to experimentally examine the practical implementation of these new insights. Four experiments were performed in the 2021/2 and 2022/3 seasons in commercial groves under natural epidemics. The results demonstrated that application of 1 or 2 sprays before or after the first major rain event in the season (the presumed time of infections that generate the second disease episode) significantly reduces disease development. The level of disease suppression achieved by these sprays was not inferior to the level of disease control achieved by 9 consecutive sprays in a season. The effect of the application in one season on peacock eye development in the following season was evaluated in the same groves, and it was found that if the disease is not controlled during two consecutive seasons, its severity increases markedly in the succeeding season, but if the disease is properly managed in the first season, its severity in the succeeding season may be minute or even non-existent.

Determining the causal agents of Alternaria leaf blight and head rot affecting broccoli in the Eastern United States

2025-05-22

Roy L. Davis , D. García , Alberto Martı́n +7 more

Alternaria brassicicola is the causal agent typically associated with Alternaria leaf blight and head rot (ABHR) disease in broccoli and related crops in the Eastern United States. Recently a new … Alternaria brassicicola is the causal agent typically associated with Alternaria leaf blight and head rot (ABHR) disease in broccoli and related crops in the Eastern United States. Recently a new species, A. japonica, has been reported as causing disease in broccoli and other vegetables in this region. We conducted a multi-state pathogen survey during the growing seasons of 2022 and 2023 to assess the distribution and occurrence of A. japonica in relation to A. brassicicola in five broccoli-producing states. Our approach specifically targeted collection of broccoli leaves with lesions typical of ABHR within commercially grown fields managed using either organic or conventional approaches in Connecticut, Massachusetts, New York, Virginia, and Georgia. Only typical ABHR leaf lesions were selected for pathogen isolation and, subsequently, sequencing of the Alternaria major allergen a1 gene was used to identify Alternaria species. The predominant species isolated was A. brassicicola (88% in 2022 and 94% in 2023) and the second most common was A. alternata (12% in 2022 and 6% in 2023), which was obtained from fields in Connecticut and Massachusetts in 2022, and in Virginia in both years. Alternaria japonica was not found in either year. Symptoms of A. alternata were indistinguishable from A. brassicicola, as were colony morphologies. While A. alternata is considered a generalist and of little consequence for broccoli, it is considered a pathogen of significance on multiple crops (blueberry, citrus, pistachios), but there remains scant information on the disease etiology on broccoli. Therefore, we inoculated broccoli with A. alternata in controlled conditions in order to shed light on possible differences in infectivity of these species on broccoli. Results of our study showed that A. alternata is pathogenic on broccoli, capable of initiating infection and causing lesions typical of ABHR. This indicates that future disease surveys of ABHR should conclusively identify species of Alternaria that are causing disease. Additional research is needed to determine the significance of this finding in relation to yield impacts, epidemiology, fungicide resistance, and management recommendations.

Comparative Efficacy of Newly Registered Fungicides for the Management of Alternaria Leaf Spot of Cauliflower in Nepal

2025-05-21

Suraj Singh Gangai , Shishir Prakash Sharma

One of the major factor contributing to the decreased yield of cauliflower in Nepal is incorrect fungicide selection and dosages. Alternaria leaf spot (ALS) caused by Alternaria brassicicola, is a … One of the major factor contributing to the decreased yield of cauliflower in Nepal is incorrect fungicide selection and dosages. Alternaria leaf spot (ALS) caused by Alternaria brassicicola, is a devastating disease that significantly reduces the quantity and quality of cauliflower. In vitro evaluation of seven different fungicides was done in a completely randomized design with five replications at different doses i.e., 50 ppm, 100 ppm, 150 ppm, and 200 ppm. All the tested fungicides significantly reduced (P≤0.001) mycelial growth of the pathogen in the poisoned food technique. The greatest reduction in mycelium growth was observed with hexaconazole and azoxystrobin + tebuconazole at the lowest tested concentration (50 ppm). Maximum inhibition of A. brassicicola growth was demonstrated by azoxystrobin + propiconazole at 200 ppm, followed by azoxystrobin + difenoconazole and copper oxychloride. The fungicides that were found effective in inhibiting mycelial growth should be tested under field conditions with multi-location and multi-strains pathogens to ensure that they meet specific requirements related to host and environment interaction. This will help to confirm their efficacy and determine the best application doses.

Unlocking the Anti-Phytopathogenic Potential of Essential Oils: A Systematic Review of Plant-Based Botrytis cinerea Management for Regenerative Viticulture and Horticultural Products

2025-05-21

Matteo Radice , Andrea Durofil , Sandra M. Ríos‐Núñez +4 more

Identification and Characterization of Alternaria Species Causing Early Blight on Tomato in Kazakhstan

2025-05-21

Assel Yessimseitova , Aisha Abdrakhmanova , Zhursinkul Tokbergenova +4 more

Early blight, caused by fungi of the genus Alternaria, is one of the most destructive diseases affecting tomato plants, leading to a decrease in yield and commercial value. Studies so … Early blight, caused by fungi of the genus Alternaria, is one of the most destructive diseases affecting tomato plants, leading to a decrease in yield and commercial value. Studies so far on Alternaria spp. affecting tomato in Kazakhstan have been limited to morphological identification or molecular analysis, without an in-depth phylogenetic study and pathogenicity assessment. In this study, between 2023 and 2024, 61 isolates were obtained from tomato leaves with early blight symptoms and identified, based on conidial morphology and DNA sequencing, as A. tenuissima (54%) and A. alternata (46%). The pathogenicity assessment showed that the disease index for A. tenuissima was 21.7–53.3, while it was 41.7–60.0 for A. alternata, indicating greater aggressiveness of the latter species. The disease index varied by region, with the highest average value recorded for A. alternata from Almaty (55.7%), while 38.2% and 36.2% for A. tenuissima were recorded from Pavlodar and Akmola, respectively. Both species showed notable intraspecific variation in pathogenicity. To our knowledge, this is the first reported case of A. tenuissima detection as the causative agent of early blight in tomato plants in Kazakhstan. The results of this study may help facilitate the development of effective disease management strategies.

Revealing TCA Cycle Flow Dynamics in Fungicide-Adapted Botrytis cinerea through Anionic Chromatographic Simultaneous Separation

2025-05-20

Yanjun Zhao , Sijia Zhao , Xiaowei Wang +3 more

The exploration of new strategies to monitor Botrytis cinerea populations is critical for disease management. This study achieved efficient and simultaneous separation of all TCA cycle intermediates in mycelia treated … The exploration of new strategies to monitor Botrytis cinerea populations is critical for disease management. This study achieved efficient and simultaneous separation of all TCA cycle intermediates in mycelia treated with pyraclostrobin (PYR), tebuconazole (TEB), and carbendazim (CAR) using anionic chromatography. Resolutions of nine organic acids and six inorganic anions, including all TCA cycle intermediates, exceeded 1.5. The fungicides inhibited mycelial growth concentration-dependently, but prolonged exposure reduced the level of inhibition. TEB decreased fumarate and malate levels at 48 h, increased citrate, isocitrate, and oxalate levels and reduced α-ketoglutarate levels at 96 h. PYR showed biphasic effects, elevating fumarate, malate, and succinate at both time points but reducing citrate and succinate at 96 h. CAR attenuated TCA cycle flow, with isocitrate and α-ketoglutarate declining continuously. Moreover, TEB promoted oxalate accumulation, PYR had no effect, and CAR suppressed it. These findings enable precise TCA cycle assessment for fungicide adaption in B. cinerea, aiding Botrytis management.

Design, Synthesis, and antifungal activity of isochroman fused coumarins against Rhizoctonia solani**

2025-05-20

Kavita Kavita , Sumit Kumar , Parshant Kaushik +3 more

This study presents the synthesis and antifungal assessment of novel isochroman-fused coumarin derivatives against Rhizoctonia solani. The compounds were synthesized using an efficient and environmentally benign approach and demonstrated strong … This study presents the synthesis and antifungal assessment of novel isochroman-fused coumarin derivatives against Rhizoctonia solani. The compounds were synthesized using an efficient and environmentally benign approach and demonstrated strong in silico binding affinity to CYP51. In vitro assays further confirmed their antifungal activity, with compound 4e exhibiting the highest potency, achieving an ED50 value of 3.59 μM. These findings underscore the potential of isochroman-fused coumarins as eco-friendly rice sheath blight control agents.

One‐Pot Synthesis of Chiral Succinate Dehydrogenase Inhibitors and Antifungal Activity Studies

2025-05-19

Donghua Du , Yu Chen , Chao Yang +2 more

Abstract In this work, a series of novel chiral succinate dehydrogenase inhibitors (SDHIs) are synthesized through a one‐pot Rh‐catalyzed asymmetric hydrogenation‐condensation strategy. This method exhibits high efficiency (up to 1000 … Abstract In this work, a series of novel chiral succinate dehydrogenase inhibitors (SDHIs) are synthesized through a one‐pot Rh‐catalyzed asymmetric hydrogenation‐condensation strategy. This method exhibits high efficiency (up to 1000 Ton, 94% yield over two steps), high stereoselectivity (up to 99% ee), and broad substrate scope (68 examples in total), providing a superior pathway for the synthesis of such chiral fungicides. Mechanistic studies indicate that the amino group at the 2‐position of the phenyl ring acts as an activating group, enhancing the reactivity and stereoselectivity control of the reaction. Furthermore, these molecules exhibit broad‐spectrum and highly effective antifungal biological activity. Notably, enantiomers show significant differences in both in vitro and in vivo fungi‐inhibiting experiments. Especially, ( S )‐ 5f showcases an antifungal activity against Botrytis cinerea (EC 50 = 0.48 µ m ) that is much higher than that of its R enantiomer (EC 50 = 36.7 µ m ). Molecular docking calculations, molecular dynamic simulation, enzyme activity assays, and ligand‐target interaction experiments demonstrate that ( S )‐ 5f (ΔG MM‐PBSA = −18.86 kcal mol −1 , K D = 6.04 µ m ) inhibits succinate dehydrogenase more effectively than its R enantiomer (ΔG MM‐PBSA = −13.01 kcal mol −1 , K D = 8.5 µ m ). Moreover, the two enantiomers have significantly different effects on spore germination and the destruction of fungal phenotype.