Biochemistry, Genetics and Molecular Biology › Molecular Biology

Plant Reproductive Biology

Works Count: 57932

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This cluster of papers explores the molecular mechanisms underlying pollen development, including pollen tube growth, self-incompatibility, pollen wall development, male gametophyte function, receptor kinases, tapetum development, pollen germination, S-RNase interactions, fertilization mechanisms, and pectin dynamics in flowering plants.

Keywords

Pollen Tube Growth; Self-Incompatibility; Pollen Wall Development; Male Gametophyte; Receptor Kinases; Tapetum Development; Pollen Germination; S-RNase; Fertilization Mechanisms; Pectin Dynamics

Expansion of the Receptor-Like Kinase/Pelle Gene Family and Receptor-Like Proteins in Arabidopsis

2003-06-01

Shin‐Han Shiu , Anthony B. Bleecker

Abstract Receptor-like kinases (RLKs) are a family of transmembrane proteins with versatile N-terminal extracellular domains and C-terminal intracellular kinases. They control a wide range of physiological responses in plants and … Abstract Receptor-like kinases (RLKs) are a family of transmembrane proteins with versatile N-terminal extracellular domains and C-terminal intracellular kinases. They control a wide range of physiological responses in plants and belong to one of the largest gene families in the Arabidopsis genome with more than 600 members. Interestingly, this gene family constitutes 60% of all kinases in Arabidopsis and accounts for nearly all transmembrane kinases in Arabidopsis. Analysis of four fungal, six metazoan, and two Plasmodium sp. genomes indicates that the family was represented in all but fungal genomes, indicating an ancient origin for the family with a more recent expansion only in the plant lineages. The RLK/Pelle family can be divided into several subfamilies based on three independent criteria: the phylogeny based on kinase domain sequences, the extracellular domain identities, and intron locations and phases. A large number of receptor-like proteins (RLPs) resembling the extracellular domains of RLKs are also found in the Arabidopsis genome. However, not all RLK subfamilies have corresponding RLPs. Several RLK/Pelle subfamilies have undergone differential expansions. More than 33% of the RLK/Pelle members are found in tandem clusters, substantially higher than the genome average. In addition, 470 of the RLK/Pelle family members are located within the segmentally duplicated regions in the Arabidopsis genome and 268 of them have a close relative in the corresponding regions. Therefore, tandem duplications and segmental/whole-genome duplications represent two of the major mechanisms for the expansion of the RLK/Pelle family in Arabidopsis.

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Programmed cell death involved in the schizolysigenous formation of the secretory cavity in Citrus sinensis L. (Osbeck)

2010-07-01

Ying Chen , Hong Wu

BRI1/BAK1, a Receptor Kinase Pair Mediating Brassinosteroid Signaling

2002-07-01

Kyoung Hee Nam , Jianming Li

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A procedure for mapping Arabidopsis mutations using co‐dominant ecotype‐specific PCR‐based markers

1993-08-01

Andrzej Konieczny , Frederick M. Ausubel

A set of mapping markers have been designed for Arabidopsis thaliana that correspond to DNA fragments amplifed by the polymerase chain reaction (PCR). The ecotype of origin of these amplified … A set of mapping markers have been designed for Arabidopsis thaliana that correspond to DNA fragments amplifed by the polymerase chain reaction (PCR). The ecotype of origin of these amplified fragments can be determined by cleavage with a restriction endo‐nuclease. Specifically, 18 sets of PCR primers were synthesized, each of which amplifies a single mapped DNA sequence from the Columbia and Landsberg erecta ecotypes. Also identifed was at least one restriction endonuclease for each of these PCR products that generates ecotype‐specific digestion patterns. Using these co‐dominant cleaved amplified polymorphic sequences (CAPS), an Arabidopsis gene can be unambiguously mapped to one of the 10 Arabidopsis chromosome arms in a single cross using a limited number of F 2 progeny.

SNARE-protein-mediated disease resistance at the plant cell wall

2003-10-01

Nicholas C. Collins , Hans Thordal‐Christensen , Volker Lipka +7 more

Induction of male sterility in plants by a chimaeric ribonuclease gene

1990-10-01

Celestina Mariani , Marc De Beuckeleer , Jessie S. Truettner +2 more

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floricaula: A homeotic gene required for flower development in antirrhinum majus

1990-12-01

Enrico Coen , J. Romero , Sandra Doyle +3 more

Fruits: A Developmental Perspective.

1993-10-01

Glenda E. Gillaspy , Hilla Ben-David , Wilhelm Gruissem

Embryonic development in many angiosperms occurs concomitantly with the development of the ovary into a specialized organ, the fruit, which provides a suitable environment for seed maturation and often a … Embryonic development in many angiosperms occurs concomitantly with the development of the ovary into a specialized organ, the fruit, which provides a suitable environment for seed maturation and often a mechanism for the dispersa1 of mature seeds, as Darwin observed. Despite centuries of intensive genetic selection of agriculturally valuable fruit, we still lack most information about how fruits develop, how this development is coordinated with embryonic development and seed formation, and the molecular, cellular, and physiological events that control fruit growth and differentiation. The last 10 years have seen a rapid surge of information on one commercially important aspect of fruit development, fruit ripening, including the genetic control of temporal events during the ripening phase (Theologis, 1992; Theologis et al., 1992). However, fewer advances have been made on temporal and spatial controls of fruit set and growth, although from the agricultura1 point of view, these aspects are of equally critical importance. We will provide a perspective on the molecular, cellular, and physiological mechanisms that must be considered as integral parts of the fruit developmental process. The discussion below will illustrate that fruit development is a potentially useful system to learn more about complex regulatory mechanisms that control the division, growth, and differentiation of plant cells.

Expression of engrailed proteins in arthropods, annelids, and chordates

1989-09-01

Nipam H. Patel , Enrique Martı́n-Blanco , Kevin Coleman +4 more

The FLP recombinase of yeast catalyzes site-specific recombination in the drosophila genome

1989-11-01

Kent G. Golic , Susan Lindquist

The rapid evolution of reproductive proteins

2002-02-01

Willie J. Swanson , Victor D. Vacquier

The No Apical Meristem Gene of Petunia Is Required for Pattern Formation in Embryos and Flowers and Is Expressed at Meristem and Primordia Boundaries

1996-04-01

Erik Souer , Adèle van Houwelingen , Daisy Kloos +2 more

Incompatibility in Angiosperms

1977-01-01

D. de Nettancourt

Differential Staining of Aborted and Nonaborted Pollen

1969-01-01

M. P. Alexander

A single staining solution was made by compounding it in the following order (dyes were from British Drug Houses): ethanol, 10 ml; 1% malachite green in 95% ethanol, 1 ml; … A single staining solution was made by compounding it in the following order (dyes were from British Drug Houses): ethanol, 10 ml; 1% malachite green in 95% ethanol, 1 ml; distilled water, 50 ml; glycerol 25 ml; phenol, 5 gm; chloral hydrate, 5 gm; acid fuchsin 1% in water, 5 ml; orange G, 1% in water 0.5 ml; and glacial acetic acid, 1–4 ml. For best results in differentiation to give green pollen walls and red protoplasm, the staining solution should be acidified with glacial acetic acid. The amount of acid to be added depends upon thickness of the pollen walls: for very thin-walled pollen, 1 ml; for moderately thin walls, 2 ml; and for thick-walled or spiny-walled pollen, 3 ml of acid. For pollen inside non-dehiscent anthers, 4 ml of acid should be used. Staining is hastened by flaming the slide (for loose thin-walled pollen) or by immersing thick-walled pollen or anthers for 24–48 hr at 50 C. In the typical stain, aborted pollen grains are green; nonaborted, red. The method is useful for pollen inside nondehiscent anthers if these are small and not too deeply coloured naturally. The stain is very durable, especially if the coverslips are sealed with param wax. The staining solution will keep well for about a month. It is useful both for angiosperms and gymnosperm microgametes.

THE ESSENTIAL ROLE OF CALCIUM ION IN POLLEN GERMINATION AND POLLEN TUBE GROWTH

1963-10-01

J. L. Brewbaker , B. H. Kwack

Brewbaker, James L., and Beyoung H. Kwack. (U. Hawaii, Honolulu.) The essential role of calcium ion in pollen germination and pollen tube growth. Amer. Jour. Bot. 50(9): 859–865. Illus. 1963.—A … Brewbaker, James L., and Beyoung H. Kwack. (U. Hawaii, Honolulu.) The essential role of calcium ion in pollen germination and pollen tube growth. Amer. Jour. Bot. 50(9): 859–865. Illus. 1963.—A pollen population effect occurs whenever pollen grains are grown in vitro. Small pollen populations germinate and grow poorly if at all, under conditions which support excellent growth of large pollen populations. The pollen population effect is overcome completely by a growth factor obtained in water extracts of many plant tissues. This factor is shown to be the calcium ion, and its action confirmed in 86 species representing 39 plant families. Other ions (K + , Mg ++ , Na + ) serve in supporting roles to the uptake or binding of calcium. The high requirement of calcium (300–5000 ppm, as Ca (NO 3 ) 2 ·4H 2 O, for optimum growth) and low calcium content of most pollen may conspire to give calcium a governing role in the growth of pollen tubes both in vitro and in situ. It is suspected that ramifications of this role extend to the self‐incompatibilities of plants and to the curious types of arrested tube growth distinguishing, for example, the orchids. A culture medium which proved its merit in a wide variety of pollen growth studies included, in distilled water, 10% sucrose, 100 ppm H 3 BO 3 , 300 ppm Ca (NO 3 ) 2 ·4H 2 O, 200 ppm MgSO 4 ·7H 2 O and 100 ppm KNO 3 .

Chromosome Atlas of Flowering Plants.

1956-11-01

C. A. Berger , C. D. Darlington , A. P. Wylie

The Arabidopsis GNOM ARF-GEF Mediates Endosomal Recycling, Auxin Transport, and Auxin-Dependent Plant Growth

2003-01-01

Niko Geldner , Nadine Anders , Hanno Wolters +7 more

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Evolutionary Significance of Phenotypic Plasticity in Plants

1965-01-01

A. D. Bradshaw

A "MICROTUBULE" IN PLANT CELL FINE STRUCTURE

1963-10-01

Myron C. Ledbetter , Keith R. Porter

This paper reports an electron microscope examination of the cortices of some plant cells engaged in wall formation. Previous studies of similar material fixed in OSO(4) alone have disclosed discontinuities … This paper reports an electron microscope examination of the cortices of some plant cells engaged in wall formation. Previous studies of similar material fixed in OSO(4) alone have disclosed discontinuities in the plasma membrane and other evidence of inadequate fixation. After glutaraldehyde, used as a fixative in this present study, the general preservation of cortical fine structure is greatly improved. This is shown, for example, by the first evidence of slender tubules, 230 to 270 A in diameter and of indeterminate length, in plant cells of this type. They have been found in the cortical regions of cells of two angiosperms and one gymnosperm, representing all the material so far studied following this method of fixation. The tubules are identical in morphology to those also observed here in the mitotic spindles of plant cells, except that the latter have a somewhat smaller diameter. It is noted that the cortical tubules are in a favored position to govern cytoplasmic streaming and to exert an influence over the disposition of cell wall materials. In this regard it may be of some significance that the tubules just beneath the surface of the protoplast mirror the orientation of the cellulose microfibrils of the adjacent cell walls.

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Identification of CRE1 as a cytokinin receptor from Arabidopsis

2001-02-01

Tsutomu Inoue , Masayuki Higuchi , Yukari Hashimoto +6 more

Receptor-like kinases from Arabidopsis form a monophyletic gene family related to animal receptor kinases

2001-08-28

Shin‐Han Shiu , Anthony B. Bleecker

Plant receptor-like kinases (RLKs) are proteins with a predicted signal sequence, single transmembrane region, and cytoplasmic kinase domain. Receptor-like kinases belong to a large gene family with at least 610 … Plant receptor-like kinases (RLKs) are proteins with a predicted signal sequence, single transmembrane region, and cytoplasmic kinase domain. Receptor-like kinases belong to a large gene family with at least 610 members that represent nearly 2.5% of Arabidopsis protein coding genes. We have categorized members of this family into subfamilies based on both the identity of the extracellular domains and the phylogenetic relationships between the kinase domains of subfamily members. Surprisingly, this structurally defined group of genes is monophyletic with respect to kinase domains when compared with the other eukaryotic kinase families. In an extended analysis, animal receptor kinases, Raf kinases, plant RLKs, and animal receptor tyrosine kinases form a well supported group sharing a common origin within the superfamily of serine/threonine/tyrosine kinases. Among animal kinase sequences, Drosophila Pelle and related cytoplasmic kinases fall within the plant RLK clade, which we now define as the RLK/Pelle family. A survey of expressed sequence tag records for land plants reveals that mosses, ferns, conifers, and flowering plants have similar percentages of expressed sequence tags representing RLK/Pelle homologs, suggesting that the size of this gene family may have been close to the present-day level before the diversification of land plant lineages. The distribution pattern of four RLK subfamilies on Arabidopsis chromosomes indicates that the expansion of this gene family is partly a consequence of duplication and reshuffling of the Arabidopsis genome and of the generation of tandem repeats.

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fw2.2 : A Quantitative Trait Locus Key to the Evolution of Tomato Fruit Size

2000-07-07

Anne Frary , Teresa Nesbitt , Amy Frary +7 more

Domestication of many plants has correlated with dramatic increases in fruit size. In tomato, one quantitative trait locus (QTL), fw2.2 , was responsible for a large step in this process. … Domestication of many plants has correlated with dramatic increases in fruit size. In tomato, one quantitative trait locus (QTL), fw2.2 , was responsible for a large step in this process. When transformed into large-fruited cultivars, a cosmid derived from the fw2.2 region of a small-fruited wild species reduced fruit size by the predicted amount and had the gene action expected for fw2.2 . The cause of the QTL effect is a single gene, ORFX , that is expressed early in floral development, controls carpel cell number, and has a sequence suggesting structural similarity to the human oncogene c-H- ras p21. Alterations in fruit size, imparted by fw2.2 alleles, are most likely due to changes in regulation rather than in the sequence and structure of the encoded protein.

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The CLAVATA1Gene Encodes a Putative Receptor Kinase That Controls Shoot and Floral Meristem Size in Arabidopsis

1997-05-01

Steven E. Clark , Robert W. Williams , Elliot M. Meyerowitz

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Molecular identification and isolation of the Waxy locus in maize

1983-11-01

Mavis Shure , Susan R. Wessler , Nina V. Fedoroff

Evaluation of Pollen Viability by Enzymatically Induced Fluorescence; Intracellular Hydrolysis of Fluorescein Diacetate

1970-01-01

J. S. Heslop‐Harrison , Y. Heslop-Harrison

AbstractViable pollen grains immersed in a solution of fluorescein diacetate, made up in a concentration of about 10−6 M in sucrose of suitable tonicity (usually about 0.5 M), rapidly accumulate … AbstractViable pollen grains immersed in a solution of fluorescein diacetate, made up in a concentration of about 10−6 M in sucrose of suitable tonicity (usually about 0.5 M), rapidly accumulate free fluorescein, which can be detected by its fluorescence. This fluorochromatic reaction (FCR) probably depends upon the entry of the nonpolar substrate into the vegetative cell where it is hydrolyzed by esterase to give the polar product, fluorescein, which is retained by the cell membrane. The test is primarily one for the integrity of the plasmalemma of the vegetative cell. Since this integrity is likely to be closely correlated with viability, the FCR provides an effective method for assessing pollen quality.

Brassinolide, a plant growth-promoting steroid isolated from Brassica napus pollen

1979-09-01

Michael D. Grove , Gayland F. Spencer , W. K. Rohwedder +6 more

The Origins of Genomic Duplications in Arabidopsis

2000-12-15

Todd Vision , Daniel G. Brown , Steven D. Tanksley

Large segmental duplications cover much of the Arabidopsis thaliana genome. Little is known about their origins. We show that they are primarily due to at least four different large-scale duplication … Large segmental duplications cover much of the Arabidopsis thaliana genome. Little is known about their origins. We show that they are primarily due to at least four different large-scale duplication events that occurred 100 to 200 million years ago, a formative period in the diversification of the angiosperms. A better understanding of the complex structural history of angiosperm genomes is necessary to make full use of Arabidopsis as a genetic model for other plant species.

A MADS-Box Gene Necessary for Fruit Ripening at the Tomato Ripening-Inhibitor ( Rin ) Locus

2002-04-12

Julia Vrebalov , Diane Ruezinsky , V. Padmanabhan +5 more

Tomato plants harboring the ripening - inhibitor ( rin ) mutation yield fruits that fail to ripen. Additionally, rin plants display enlarged sepals and loss of inflorescence determinacy. Positional cloning … Tomato plants harboring the ripening - inhibitor ( rin ) mutation yield fruits that fail to ripen. Additionally, rin plants display enlarged sepals and loss of inflorescence determinacy. Positional cloning of the rin locus revealed two tandem MADS-box genes ( LeMADS - RIN and LeMADS - MC ), whose expression patterns suggested roles in fruit ripening and sepal development, respectively. The rin mutation alters expression of both genes. Gene repression and mutant complementation demonstrate that LeMADS - RIN regulates ripening, whereas LeMADS - MC affects sepal development and inflorescence determinacy. LeMADS - RIN demonstrates an agriculturally important function of plant MADS-box genes and provides molecular insight into nonhormonal (developmental) regulation of ripening.

Signaling of Cell Fate Decisions by CLAVATA3 in Arabidopsis Shoot Meristems

1999-03-19

Jennifer C. Fletcher , Ulrike Brand , Mark Running +2 more

In higher plants, organogenesis occurs continuously from self-renewing apical meristems. Arabidopsis thaliana plants with loss-of-function mutations in the CLAVATA (CLV1 , 2 , and 3) genes have enlarged meristems and … In higher plants, organogenesis occurs continuously from self-renewing apical meristems. Arabidopsis thaliana plants with loss-of-function mutations in the CLAVATA (CLV1 , 2 , and 3) genes have enlarged meristems and generate extra floral organs. Genetic analysis indicates that CLV1 , which encodes a receptor kinase, acts with CLV3 to control the balance between meristem cell proliferation and differentiation. CLV3 encodes a small, predicted extracellular protein. CLV3 acts nonautonomously in meristems and is expressed at the meristem surface overlying the CLV1 domain. These proteins may act as a ligand-receptor pair in a signal transduction pathway, coordinating growth between adjacent meristematic regions.

The Role of Hybridization in Plant Speciation

2009-01-23

Pamela S. Soltis

The importance of hybridization in plant speciation and evolution has been debated for decades, with opposing views of hybridization as either a creative evolutionary force or evolutionary noise. Hybrid speciation … The importance of hybridization in plant speciation and evolution has been debated for decades, with opposing views of hybridization as either a creative evolutionary force or evolutionary noise. Hybrid speciation may occur at either the homoploid (i.e., between two species of the same ploidy) or the polyploid level, each with its attendant genetic and evolutionary consequences. Whereas allopolyploidy (i.e., resulting from hybridization and genome doubling) has long been recognized as an important mode of plant speciation, the implications of genome duplication have typically not been taken into account in most fields of plant biology. Recent developments in genomics are revolutionizing our views of angiosperm genomes, demonstrating that perhaps all angiosperms have likely undergone at least one round of polyploidization and that hybridization has been an important force in generating angiosperm species diversity. Hybridization and polyploid formation continue to generate species diversity, with several new allopolyploids having originated just within the past century or so. The origins of polyploid species—whether via hybridization between species or between genetically differentiated populations of a single species—and the immediate genetic consequences of polyploid formation are therefore receiving enthusiastic attention. The time is therefore right for a review of the role of hybridization in plant speciation.

Synteny and Collinearity in Plant Genomes

2008-04-24

Haibao Tang , John Bowers , Xiyin Wang +3 more

Correlated gene arrangements among taxa provide a valuable framework for inference of shared ancestry of genes and for the utilization of findings from model organisms to study less-well-understood systems. In … Correlated gene arrangements among taxa provide a valuable framework for inference of shared ancestry of genes and for the utilization of findings from model organisms to study less-well-understood systems. In angiosperms, comparisons of gene arrangements are complicated by recurring polyploidy and extensive genome rearrangement. New genome sequences and improved analytical approaches are clarifying angiosperm evolution and revealing patterns of differential gene loss after genome duplication and differential gene retention associated with evolution of some morphological complexity. Because of variability in DNA substitution rates among taxa and genes, deviation from collinearity might be a more reliable phylogenetic character.

Anther developmental defects in Arabidopsis thaliana male-sterile mutants

1999-01-22

P. Sanders , Anhthu Q. Bui , Koen Weterings +6 more

Functional markers in plants

2003-10-16

Jeppe Reitan Andersen , Thomas Lübberstedt

Teaching Sign Language to a Chimpanzee

1969-08-15

Rod Gardner , Beatrice T. Gardner

Speciation often involves the evolution of incompatible gene interactions that cause sterility or lethality in hybrids between populations. These so-called hybrid incompatibilities occur between two or more functionally divergent loci. … Speciation often involves the evolution of incompatible gene interactions that cause sterility or lethality in hybrids between populations. These so-called hybrid incompatibilities occur between two or more functionally divergent loci. We show that the nucleoporin 160kDa (Nup160) gene of the fruitfly Drosophila simulans is incompatible with one or more factors on the D. melanogaster X chromosome, causing hybrid lethality. Nup160 encodes a nuclear pore complex protein and shows evidence of adaptive evolution. Furthermore, the protein encoded by Nup160 directly interacts with that of another hybrid lethality gene, Nup96, indicating that at least two lethal hybrid incompatibility genes have evolved as byproducts of divergent coevolution among interacting components of the Drosophila nuclear pore complex.

POLLEN GERMINATION AND TUBE GROWTH

1997-06-01

Loverine P. Taylor , Peter K. Hepler

Many aspects of Angiosperm pollen germination and tube growth are discussed including mechanisms of dehydration and rehydration, in vitro germination, pollen coat compounds, the dynamic involvement of cytoskeletal elements (actin, … Many aspects of Angiosperm pollen germination and tube growth are discussed including mechanisms of dehydration and rehydration, in vitro germination, pollen coat compounds, the dynamic involvement of cytoskeletal elements (actin, microtubules), calcium ion fluxes, extracellular matrix elements (stylar arabinogalactan proteins), and control mechanisms of gene expression in dehydrating and germinating pollen. We focus on the recent developments in pollen biology that help us understand how the male gamete survives and accomplishes its successful delivery to the ovule of the sperm to effect sexual reproduction.

Gibberellin Metabolism and its Regulation

2008-01-03

Shinjiro Yamaguchi

Bioactive gibberellins (GAs) are diterpene plant hormones that are biosynthesized through complex pathways and control diverse aspects of growth and development. Biochemical, genetic, and genomic approaches have led to the … Bioactive gibberellins (GAs) are diterpene plant hormones that are biosynthesized through complex pathways and control diverse aspects of growth and development. Biochemical, genetic, and genomic approaches have led to the identification of the majority of the genes that encode GA biosynthesis and deactivation enzymes. Recent studies have highlighted the occurrence of previously unrecognized deactivation mechanisms. It is now clear that both GA biosynthesis and deactivation pathways are tightly regulated by developmental, hormonal, and environmental signals, consistent with the role of GAs as key growth regulators. In some cases, the molecular mechanisms for fine-tuning the hormone levels are beginning to be uncovered. In this review, I summarize our current understanding of the GA biosynthesis and deactivation pathways in plants and fungi, and discuss how GA concentrations in plant tissues are regulated during development and in response to environmental stimuli.

CHROMOSOME ORGANIZATION AND GENIC EXPRESSION

1951-01-01

Barbara McClintock

During the past six years, a study of the behavior of a number of newly arisen mutable loci in maize has been undertaken. This study has provided a unique opportunity … During the past six years, a study of the behavior of a number of newly arisen mutable loci in maize has been undertaken. This study has provided a unique opportunity to examine the mutation process at a number of different loci in the chromosomes. For some of these loci, several independent inceptions of instability have occurred during the progress of this study. The types of mutation that appear, and the types of instability expression, need not be the same at any one locus. In fact, comparisons of the behavior of these different mutable conditions at a particular locus have shown striking diversity, not only with regard to the changes in phenotypic expression that result from mutations at the locus, but also with regard to the manner in which mutability is controlled. Knowledge of the genetic constitutions, with respect to mutable loci already present in the plants in which new mutable...

Variation and Evolution in Plants

1950-12-31

G. Ledyard Stebbins

BRASSINOSTEROIDS: Essential Regulators of Plant Growth and Development

1998-06-01

Steven D. Clouse , Jenneth M. Sasse

Brassinosteroids (BRs) are growth-promoting natural products found at low levels in pollen, seeds, and young vegetative tissues throughout the plant kingdom. Detailed studies of BR biosynthesis and metabolism, coupled with … Brassinosteroids (BRs) are growth-promoting natural products found at low levels in pollen, seeds, and young vegetative tissues throughout the plant kingdom. Detailed studies of BR biosynthesis and metabolism, coupled with the recent identification of BR-insensitive and BR-deficient mutants, has greatly expanded our view of steroids as signals controlling plant growth and development. This review examines the microchemical and molecular genetic analyses that have provided convincing evidence for an essential role of BRs in diverse developmental programs, including cell expansion, vascular differentiation, etiolation, and reproductive development. Recent advances relevant to the molecular mechanisms of BR-regulated gene expression and BR signal transduction are also discussed.

Ectopic Expression of BABY BOOM Triggers a Conversion from Vegetative to Embryonic Growth

2002-07-18

Kim Boutilier , Remko Offringa , Vijay K. Sharma +7 more

The molecular mechanisms underlying the initiation and maintenance of the embryonic pathway in plants are largely unknown. To obtain more insight into these processes, we used subtractive hybridization to identify … The molecular mechanisms underlying the initiation and maintenance of the embryonic pathway in plants are largely unknown. To obtain more insight into these processes, we used subtractive hybridization to identify genes that are upregulated during the in vitro induction of embryo development from immature pollen grains of Brassica napus (microspore embryogenesis). One of the genes identified, BABY BOOM (BBM), shows similarity to the AP2/ERF family of transcription factors and is expressed preferentially in developing embryos and seeds. Ectopic expression of BBM in Arabidopsis and Brassica led to the spontaneous formation of somatic embryos and cotyledon-like structures on seedlings. Ectopic BBM expression induced additional pleiotropic phenotypes, including neoplastic growth, hormone-free regeneration of explants, and alterations in leaf and flower morphology. The expression pattern of BBM in developing seeds combined with the BBM overexpression phenotype suggests a role for this gene in promoting cell proliferation and morphogenesis during embryogenesis.

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The Arabidopsis Receptor Kinase FLS2 Binds flg22 and Determines the Specificity of Flagellin Perception

2005-12-23

Delphine Chinchilla , Zsuzsa Bauer , Martin Regenass +2 more

Abstract Flagellin, the main building block of the bacterial flagellum, acts as a pathogen-associated molecular pattern triggering the innate immune response in animals and plants. In Arabidopsis thaliana, the Leu-rich … Abstract Flagellin, the main building block of the bacterial flagellum, acts as a pathogen-associated molecular pattern triggering the innate immune response in animals and plants. In Arabidopsis thaliana, the Leu-rich repeat transmembrane receptor kinase FLAGELLIN SENSITIVE2 (FLS2) is essential for flagellin perception. Here, we demonstrate the specific interaction of the elicitor-active epitope flg22 with the FLS2 protein by chemical cross-linking and immunoprecipitation. The functionality of this receptor was further tested by heterologous expression of the Arabidopsis FLS2 gene in tomato (Lycopersicon esculentum) cells. The perception of flg22 in tomato differs characteristically from that in Arabidopsis. Expression of Arabidopsis FLS2 conferred an additional flg22-perception system on the cells of tomato, which showed all of the properties characteristic of the perception of this elicitor in Arabidopsis. In summary, these results show that FLS2 constitutes the pattern-recognition receptor that determines the specificity of flagellin perception.

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Staining and Observing Pollen Tubes in the Style by Means of Fluorescence

1959-01-01

Franklin W. Martin

AbstractPollen tubes in the styles of the tomato and of other flowering plants can be observed by using the following technic. Styles are fixed in formalin-acetic-80% alcohol (1:1:8) and cleared … AbstractPollen tubes in the styles of the tomato and of other flowering plants can be observed by using the following technic. Styles are fixed in formalin-acetic-80% alcohol (1:1:8) and cleared and softened in a strong (8 N) sodium hydroxide solution. Staining is accomplished in a 0.1% solution of water-soluble aniline blue dye dissolved in 0.1 N, K3PO4. The styles are smeared or are observed whole under a conventional or dissecting microscope by direct illumination with ultraviolet light of a wavelength of about 356 m°. Observations are made in a darkened room. Under these conditions callose fluoresces bright yellow-green and contrasts strongly with the bluish or grayish fluorescence of the stylar tissue. The pollen tubes are outlined by a callose lining and irregularly spaced callose plugs.

Quantitative analysis of major plant hormones in crude plant extracts by high-performance liquid chromatography–mass spectrometry

2010-05-06

Xiangqing Pan , Ruth Welti , Xuemin Wang

CYTOKININS: Activity, Biosynthesis, and Translocation

2006-02-01

Hitoshi Sakakibara

Cytokinins (CKs) play a crucial role in various phases of plant growth and development, but the basic molecular mechanisms of their biosynthesis and signal transduction only recently became clear. The … Cytokinins (CKs) play a crucial role in various phases of plant growth and development, but the basic molecular mechanisms of their biosynthesis and signal transduction only recently became clear. The progress was achieved by identifying a series of key genes encoding enzymes and proteins controlling critical steps in biosynthesis, translocation, and signaling. Basic schemes for CK homeostasis and root/shoot communication at the whole-plant level can now be devised. This review summarizes recent findings on the relationship between CK structural variation and activity, distinct features in CK biosynthesis between higher plants and Agrobacterium infected plants, CK translocation at whole-plant and cellular levels, and CKs as signaling molecules for nutrient status via root-shoot communication.

Pattern and Process in the Plant Community

1947-12-01

A. S. Watt

Secretory Tissues in Plants:

1980-01-01

M. Y. Stant

Plant Speciation

2007-08-16

Loren H. Rieseberg , John H. Willis

Like the formation of animal species, plant speciation is characterized by the evolution of barriers to genetic exchange between previously interbreeding populations. Prezygotic barriers, which impede mating or fertilization between … Like the formation of animal species, plant speciation is characterized by the evolution of barriers to genetic exchange between previously interbreeding populations. Prezygotic barriers, which impede mating or fertilization between species, typically contribute more to total reproductive isolation in plants than do postzygotic barriers, in which hybrid offspring are selected against. Adaptive divergence in response to ecological factors such as pollinators and habitat commonly drives the evolution of prezygotic barriers, but the evolutionary forces responsible for the development of intrinsic postzygotic barriers are virtually unknown and frequently result in polymorphism of incompatibility factors within species. Polyploid speciation, in which the entire genome is duplicated, is particularly frequent in plants, perhaps because polyploid plants often exhibit ecological differentiation, local dispersal, high fecundity, perennial life history, and self-fertilization or asexual reproduction. Finally, species richness in plants is correlated with many biological and geohistorical factors, most of which increase ecological opportunities.

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Incompatibility and Incongruity in Wild and Cultivated Plants

2001-01-01

D. de Nettancourt

Female gametophyte development, pollen‒pistil interactions and embryogenic patterns in chicory (Cichorium intybus): a self-incompatibility perspective

2025-06-25

Samela Draga , Fabio Palumbo , Damiano Riommi +6 more | Plant Cell Reports

Cytological and molecular investigations in chicory revealed crucial aspects related to female gametophyte development, pollen‒stigma interactions, and self-incompatibility responses. The Asteraceae family, one of the largest of angiosperms, comprises approximately … Cytological and molecular investigations in chicory revealed crucial aspects related to female gametophyte development, pollen‒stigma interactions, and self-incompatibility responses. The Asteraceae family, one of the largest of angiosperms, comprises approximately 24,000 species and exhibits considerable variation in reproductive biology. Cichorium intybus (commonly known as chicory) is among the most well-known and widespread species of the family. In addition to its economic and commercial value, chicory is considered one of the most interesting species in its family for the study of sporophytic self-incompatibility (SSI). Information regarding megasporogenesis, megagametogenesis, pollen tube development, and embryogenesis in this species is almost entirely absent in the scientific literature. Using confocal laser scanning microscopy (CLSM), we conducted a detailed investigation of female gametophyte development, providing a comprehensive characterization of the cytological stages involved in megasporogenesis and megagametogenesis. To investigate the dynamics and timing of pollen tube development and pollen rejection, we microscopically examined the interactions between pollen and stigmas in both cross- and self-pollinated plants. The response was similar to those documented in other Asteraceae species with a 'semidry' type of stigma. Integrated RNA-seq analyses further highlighted transcriptional changes during self- and non-self-pollen recognition and led to the identification of potential candidate genes involved in pollen tube development and callose deposition (in the case of self-incompatibility reactions). In parallel, for the first time, we characterized both the embryogenesis process and embryo sac degeneration in a compatible and incompatible crosses, respectively.

Whole genome duplication enables rapid evolution of male-biased sex allocation inGalax urceolata

2025-06-25

Joseph H. Williams | bioRxiv (Cold Spring Harbor Laboratory)

Sex allocation in hermaphrodites is thought to evolve to a balance between fitness gained through male and female function. Whole genome duplication (WGD) might disrupt such gradually evolved patterns, since … Sex allocation in hermaphrodites is thought to evolve to a balance between fitness gained through male and female function. Whole genome duplication (WGD) might disrupt such gradually evolved patterns, since it has relatively instantaneous effects on sizes, but not numbers, of cells and organs. Here we ask whether sex allocation patterns differ between young neo-autotetraploid populations and their diploid progenitors within Galax urceolata . Floral organ sizes and numbers were measured using light microscopy and genome sizes verified with flow cytometry. Both cytotypes had the same number of flowers, anthers, and ovules per inflorescence, but floral organ sizes were proportionally longer in autotetraploids relative to diploid progenitors. Whole-plant allocation to volume of anthers increased by 176%, but of ovules only 70%. Autotetraploids produced 33% larger and 88% more pollen. WGD is known to double pollen volume, but pollen is biased to size reduction in young natural autotetraploids. In WGD-enlarged anthers, pollen size reduction allows increased pollen number to evolve without changing anther size. A literature review shows that higher pollen production in autopolyploid species is common, but not inevitable. Thus, we conclude that polyploidy can provide a pathway to increased pollen production, which may enhance male fitness during their early evolution.

Angiosperms (Flowering plants)

2025-06-24

| Princeton University Press eBooks

Comparative plastomes of five Psittacanthus species: genome organization, structural features, and patterns of pseudogenization and gene loss

2025-06-24

Saddan Morales‐Saldaña , Andrea I Barraza-Ochoa , Emanuel Villafán +4 more | AoB Plants

Abstract The evolution of heterotrophic lifestyle entails varying degrees of plastome degradation. Yet, the evolutionary trajectory of plastome degradation associated with parasitism remains poorly explored in hemiparasites. We sequenced, assembled … Abstract The evolution of heterotrophic lifestyle entails varying degrees of plastome degradation. Yet, the evolutionary trajectory of plastome degradation associated with parasitism remains poorly explored in hemiparasites. We sequenced, assembled and annotated the complete plastomes of five species of Psittacanthus mistletoes. In addition, publicly available plastomes of 58 species in Loranthaceae were obtained and reannotated for phylogenetic and comparative analyses. We used a comparative-phylogenetic approach to evaluate whether patterns of pseudogenization and gene loss differ among lineages of hemiparasites in Loranthaceae. Gene order was highly conserved, with higher sequence similarity and structural conservation between closely-related Psittacanthus species but with considerable plastome size variation (from 121,238 bp to 125,427 bp). The expansion and contraction at the borders of inverted repeats and intergenic regions variation greatly contribute to size variations among Psittacanthus plastomes. Phylogenetic analysis of plastomes of 60 species in Loranthaceae including five Psittacanthus species of the previously unsampled tribe Psittacantheae were largely congruent with previous phylogenetic studies. The loss of most of the ndh complex (10 out of 11 genes), rpl32, rps15, and rps16 genes, were identified in all studied Psittacanthus species. Also, the loss and pseudogenization of rpl33 and rpl36 genes in Psittacanthus was uncommon in other Loranthaceae species. The structural variation uncovered in Psittacanthus plastomes reveals that, despite high synteny, significant size variation exists among species. This variation can be attributed to processes such as variations in the length of intergenic regions and the expansion/contraction of inverted repeat borders, traits that have been comparatively understudied in earlier Loranthaceae works.

Relationship among carbohydrates content, viability and germinability in pollen of European hazelnut (Corylus avellana L.) cultivars

2025-06-24

Claudio Brandoli , Giacomo Dito , Sergio Tombesi +3 more | Horticulture Environment and Biotechnology

Gymnosperms

2025-06-24

| Princeton University Press eBooks

In Vitro Live Cell Imaging Reveals Nuclear Dynamics and Role of the Cytoskeleton During Asymmetric Division of Pollen Mitosis I in <scp>Nicotiana Benthamiana</scp>

2025-06-24

Yoko Mizuta , Masako Igarashi , Tomomi Shinagawa +3 more | Cytoskeleton

Pollen is a male gametophyte of angiosperms. Following meiosis, the microspore undergoes an asymmetric division called pollen mitosis I (PMI), which produces two cells of different sizes: a large vegetative … Pollen is a male gametophyte of angiosperms. Following meiosis, the microspore undergoes an asymmetric division called pollen mitosis I (PMI), which produces two cells of different sizes: a large vegetative cell and a small generative cell. Polarized nuclear migration and positioning during PMI are important for successful pollen development and cell differentiation. However, analyzing the pollen development process in real-time is challenging in many model plants with tricellular pollen, including Arabidopsis and rice. In this study, we established a method for live confocal imaging of microtubule and actin dynamics using suspension cultures with biolistic delivery of plasmid DNAs during PMI in Nicotiana benthamiana (Bentham's tobacco), containing bicellular pollen. Pharmacological studies have indicated that actin filaments are crucial for microspore nuclear positioning before PMI, cell plate expansion during cytokinesis, and chromatin dispersion in the vegetative cell nucleus after PMI. By contrast, the inhibition of microtubule assembly resulted in abnormal chromosome segregation and nuclear behavior after PMI, although nuclear positioning and asymmetric division were observed. Our in vitro live cell imaging system for PMI provides insights into the importance of cytoskeletal regulation in asymmetric division and differentiation during pollen development.

Wurzel mit Riechfunktion

2025-06-23

Magga Corts | DO - Deutsche Zeitschrift für Osteopathie

Enantiostyly: clockwise or anticlockwise rotation ensures self-fertilization in mirror-image flowers

2025-06-22

Wei Jiang , Guang-Xi Wang , Yi Wang +1 more | New Zealand Journal of Botany

Reciprocal regulation between AtFH5‐labeled secretory vesicles and PI(4,5)P2 oscillation at the plasma membrane directs pollen germination

2025-06-20

Yuwan Zhao , Zijing Huang , Ting Wang +4 more | Journal of Integrative Plant Biology

ABSTRACT Phosphatidylinositol 4,5‐bisphosphate (PI(4,5)P 2 ) is known to be an instrumental anionic phospholipid in governing pollen germination and pollen tube growth. However, the precise functions and regulatory mechanisms of … ABSTRACT Phosphatidylinositol 4,5‐bisphosphate (PI(4,5)P 2 ) is known to be an instrumental anionic phospholipid in governing pollen germination and pollen tube growth. However, the precise functions and regulatory mechanisms of PI(4,5)P 2 in pollen polarity establishment and germination remain poorly understood. Our previous studies demonstrated the pivotal involvement of Arabidopsis formin homology 5 (AtFH5)‐dependent vesicle trafficking in polarity establishment of pollen. Here, we observed that PI(4,5)P 2 accumulated and oscillated at the prospective germination site, a process closely associated with the rotational movement of AtFH5‐labeled vesicles. Disruption of the mobility of AtFH5‐labeled vesicles, either through AtFH5 mutation or pharmacological treatment, significantly perturbed the accumulation of PI(4,5)P 2 at the plasma membrane. Subcellular localization and genetic analysis revealed that two phosphatidylinositol 4‐phosphate 5‐kinases, AtPIP5K1 and AtPIP5K4, are essential for PI(4,5)P 2 oscillation at the germination site prior to pollen germination. Furthermore, we found that the dynamics of AtPIP5K4 depended on the mobility of AtFH5‐labeled vesicles and reduced PI(4,5)P 2 in turn disturbed the attachment of AtFH5‐labeled secretory vesicles to the plasma membrane. In conclusion, these findings collectively highlight the reciprocal regulation of AtFH5‐labeled secretory vesicles and PI(4,5)P 2 oscillations at the plasma membrane, providing critical insights into the molecular mechanism underlying polarity establishment during pollen germination.

Genomic evidence unveils the genetic architecture and evolution of the S‐locus controlling heterostyly in Rubiaceae

2025-06-20

Shuai Yuan , Spencer C. H. Barrett , Chuqiao Tang +6 more | New Phytologist

Summary The S ‐locus supergene controlling heterostyly has multiple angiosperm origins and is characterized by convergent evolution in form and function. The genetic architecture of floral polymorphism has been studied … Summary The S ‐locus supergene controlling heterostyly has multiple angiosperm origins and is characterized by convergent evolution in form and function. The genetic architecture of floral polymorphism has been studied in several unrelated families, but not Rubiaceae, which has the largest number of heterostylous species. We assembled genomes of the long‐ and short‐styled morphs of distylous Mussaenda lancipetala and investigated the structure and evolution of the S‐locus in three Mussaenda species to evaluate evidence for convergence in genetic architecture and gene function in unrelated families. Genome assemblies and population genomics indicated that the S ‐locus in M. lancipetala is comprised of three hemizygous genes – MuIAA , MuGA3ox , and MuAPs – present only in the S‐morph. In each species, MuIAA , involved in the auxin response pathway, was highly expressed in pistils and floral tubes of the S‐morph, and is a likely candidate gene controlling style length. Molecular evolution analysis indicated that the S ‐haplotype has accumulated repetitive sequences, S ‐linked genes showed no evidence of relaxed purifying selection, and the evolutionary assembly of the S ‐locus involved stepwise duplication. Our findings provide support for the prevalence of hemizygosity in S ‐locus genes and have identified molecular pathways underpinning convergent morphological evolution of clear adaptive significance.

Gene Co‐Expression Network Analysis Reveals AsAMS as a Key Regulator of Gametophyte Fertility in Garlic

2025-06-20

Jie Ge , Guangyang Liu , Qin Yang +7 more | Plant Cell & Environment

ABSTRACT The reproductive cycle of plants features a crucial transition between diploid sporophytic and haploid gametophytic generations. In garlic ( Allium sativum L.), a lack of gametophyte fertility poses significant … ABSTRACT The reproductive cycle of plants features a crucial transition between diploid sporophytic and haploid gametophytic generations. In garlic ( Allium sativum L.), a lack of gametophyte fertility poses significant challenges for breeding. This study conducted a comprehensive comparative transcriptomic analysis across three developmental stages of garlic floral buds from three genotypes with varied fertility profiles to unravel the genetic underpinnings of gametophyte development. Through differential expression analysis and weighted gene co‐expression network analysis, we identified key pathways and genes influencing gametophyte fertility. Our findings provided a comprehensive framework that reveals both shared and sex‐specific regulatory mechanisms in garlic gametophyte development. Lipid metabolism appeared to be a common pathway influencing the fertility of both male and female gametes, whereas ribosome biogenesis was crucial for female gametophyte development. Furthermore, we identified the AsAMS gene as a key regulator of male gametophyte fertility, likely orchestrating tapetal development and microspore formation by modulating lipid metabolism through a conserved tapetum network. The first functional validation using virus‐induced gene silencing in garlic further substantiated the role of AsAMS , which demonstrated its critical impact on pollen viability and morphological integrity of reproductive structures. Taken together, these findings not only deepen our understanding of the genetic mechanisms underlying gametophyte development in garlic but also shed light on potential genetic interventions to overcome fertility barriers. By delineating the pathways and key regulators such as AsAMS , this study opens new avenues for enhancing reproductive efficiency in garlic.

The cytological basis of self-incompatibility in goji (Lycium barbarum) and the cloning of S-RNase gene

2025-06-19

Jiali Wu , Xiongxiong Nan , Ken Qin +5 more | Planta

Melatonin prolongs the shelf life of snow peas by regulating the antioxidant system

2025-06-19

Shuwei Nian , Yongjia Yang , Ifra Iqrar +6 more | Journal of Stored Products Research

Bioinspired Silica Nanoparticles for Enhanced Adhesion and Retention of Biomolecules: A Sustainable and Green Strategy for Disease Management

2025-06-18

Anju Sangwan , Nitish Kumar , Neetu Singh | ACS Applied Bio Materials

The growing significance of sustainable agriculture is underscored by the escalating global demand for food and environmental degradation. Continuously adapting plant pathogens presents a significant challenge to sustainable agriculture, leading … The growing significance of sustainable agriculture is underscored by the escalating global demand for food and environmental degradation. Continuously adapting plant pathogens presents a significant challenge to sustainable agriculture, leading to substantial global crop losses. Botrytis cinerea is widely distributed and poses a menace to a diverse range of economically important crops. Conventional delivery strategies for active molecules have a low utilization rate, leading to decreased bioavailability, thus reducing the overall efficacy. Utilizing stimulus-responsive carriers for biomolecule delivery into plants enhances efficiency against target pathogens, minimizes risks to nontarget organisms and the environment, and plays a crucial role in increasing active ingredient bioavailability, reducing application frequency. Here, we have prepared a nanobiopesticide composition with foliage-adhesive properties that shows release in pathological conditions, utilizing biocompatible Guar gum/Salicylic acid (GG/SA) as the encapsulating agent on silica nanoparticles (MSNPs) as the carrier, loaded with tannic acid (TA). In comparison to the naked biomolecule, the GG/SA encapsulation improves the deposition of tannic acid, and the contact angle on tomato leaves is decreased by 28°. The enhanced antiwashing efficiency of TanMSNPGG/SA, compared to its naked biomolecule counterparts, can be attributed to low surface tension and van der Waals interactions. Different from free tannic acid, TanMSNPGG/SA exhibited a responsive release in pathological conditions, leading to sustained and steady biomolecule release and prolonged persistence time. Moreover, the control efficacy of TanMSNPGG/SA against B. cinerea was 94%. Also, they showed no cytotoxicity on NIH3T3 cells. This study anticipates improving the adhesion of biomolecules, maximizing the utilization efficiency with stimulus-responsive carriers, thereby addressing a significant application challenge in the field of agriculture, aligning with ecofriendly agricultural practices, presenting an economically viable option for farmers, and ensuring food safety.

Autopolyploidy exacerbates dominance masking under negative frequency-dependent selection : evidence from sporophytic self-incompatibility inArabidopsis arenosaandA. lyrata

2025-06-17

Xavier Vekemans , Uliana Kolesnikova , Jakub Vlček +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Polyploidy is a widespread phenomenon in flowering plants, with up to 30% of extant species being recent polyploids. Whether and how polyploidy modulates the action of natural selection remains … Abstract Polyploidy is a widespread phenomenon in flowering plants, with up to 30% of extant species being recent polyploids. Whether and how polyploidy modulates the action of natural selection remains debated, and the particular case of balancing selection has been poorly explored. This study investigates the impact of autopolyploidy on sporophytic self-incompatibility in plants, a striking example of a genetic system evolving under a special form of balancing selection (strong negative frequency-dependent selection). Numerical simulations reveal that under strict codominance, the number of S-alleles maintained in tetraploid populations is expected to double as compared to diploid populations. However, under a model with strict hierarchical dominance among alleles, the number of S-alleles increases only slightly, but gene diversity and observed heterozygosity are substantially lower in tetraploids as compared to diploids, due to enhanced dominance masking effects. Empirical data on Arabidopsis arenosa and A. lyrata confirm the latter predictions, showing similar levels of allelic diversity but dramatically lower observed and expected heterozygosity at the self-incompatibility locus in tetraploids compared to diploids. The study highlights the significant impact of autopolyploidy on patterns of diversity at the self-incompatibility locus, emphasizing the increased dominance effect in tetraploids. The results also allow us to reject a scenario of strong founder effects associated with evolution of the polyploid lineages.

Expression analyses of sweet cherry AUX/IAAs and involvements of PavAUX/IAA9/11 in regulating fruitlet abscission

2025-06-17

Qiandong Hou , Guang Qiao , Chunqiong Shang +4 more | Plant Cell Reports

Differential gene expression analysis identifies a group of defensin-like peptides from Solanum chacoense ovules with in vitro pollen tube attraction activity

2025-06-17

Yang Liu , Valentin Joly , Mohamed Sabar +2 more | Plant Molecular Biology

Ficha de Endecous apterus

2025-06-17

Márcio Perez Bolfarini , Rodrigo Lopes Ferreira , Marconi Souza‐Silva +2 more | Datasets - Sistema SALVE - ICMBio

Comprehensive Evaluation and Screening for Salt Tolerance Germplasms at Seedling Stage in Eggplant

2025-06-17

Fang Yu , Zhiguo Wang , Yu Du +7 more | Horticulturae

Salt stress presents a major environmental constraint to global agricultural productivity and crop yield stability. Eggplant (Solanum melongena L.) is one of the most extensively cultivated Solanaceae crops worldwide, and … Salt stress presents a major environmental constraint to global agricultural productivity and crop yield stability. Eggplant (Solanum melongena L.) is one of the most extensively cultivated Solanaceae crops worldwide, and the characterization of its germplasm for salt tolerance is essential to develop breeding programs to target its abiotic stress resilience. In this study, 200 mmol/L NaCl was identified as the initial screening concentration for the discrimination of salt tolerance levels in eggplant seedlings. Salt tolerance indices derived from 13 descriptors, including the plant height, stem diameter, and leaf number, were used to evaluate 165 germplasm resources (108 inbred lines and 57 commercial cultivars). These 165 germplasms were grouped into five groups, and six highly tolerant and eight highly sensitive germplasms were identified. Importantly, a stepwise multiple linear regression model incorporating the root surface area, leaf number, leaf water content, malondialdehyde content, and stem water content achieved 90.02% predictive accuracy, establishing a high-throughput screening protocol for germplasm selection. This systematic approach provides methodological advancements for precision breeding and identifies key physiological and morphological markers for salt tolerance improvement in eggplant.

CRABS CLAW‐independent floral nectary development in Penstemon barbatus

2025-06-16

Amanda M. Katzer , Carolyn A. Wessinger , Brooklyn M. Anaya +1 more | American Journal of Botany

Abstract Premise Plants secrete carbohydrate‐rich nectar from specialized floral nectary glands to attract pollinators. Arabidopsis and Petunia (rosid and asterid core eudicots, respectively) share genetic control of nectary development requiring … Abstract Premise Plants secrete carbohydrate‐rich nectar from specialized floral nectary glands to attract pollinators. Arabidopsis and Petunia (rosid and asterid core eudicots, respectively) share genetic control of nectary development requiring activation of CRABS CLAW by euAGAMOUS and PLENA . This module is conserved despite striking differences in nectary morphology between the two species. We tested whether the euAGAMOUS/PLENA‐CRABS CLAW module likely extends to an asterid species with novel nectary morphology, Penstemon barbatus . Methods To test conservation of the euAGAMOUS/PLENA‐CRABS CLAW module and nectar sugar metabolism in P. barbatus , we carried out comparative transcriptomics, leveraging Penstemon 's unique nectary morphology. Specifically, lateral and ventral stamen filaments develop with and without nectaries at their base, respectively, allowing straightforward differential expression analyses to uncover nectary‐specific gene expression. Results Many genes were differentially expressed between nectary and non‐nectary tissues, and pre‐ and post‐nectar‐removal. Differentially expressed genes pointed to key phloem, abaxial specification, and epidermal cell shape functions during nectary development. Differentially expressed genes pointed to regulation of sugar processing and secretion after nectary maturation. Conclusions Our results suggest that P. barbatus nectaries develop independently of the canonical core‐eudicot CRABS CLAW genetic module, despite being positioned within reproductive floral organ whorls, and that P. barbatus nectar production follows conserved sugar metabolic pathways.

Nivel de poliembrionía en semillas de lima mexicana y limón verdadero, estimado por conteo directo de embriones

2025-06-16

Marciano Manuel Robles González , S Carrillo , José C. García-Preciado +1 more | Brazilian Journal of Animal and Environmental Research

La poliembrionía es el resultado de un proceso biológico conocido como apomixis esporofítica, que implica el desarrollo autónomo de múltiples embriones de origen nucelar, además del embrión cigótico o sexual, … La poliembrionía es el resultado de un proceso biológico conocido como apomixis esporofítica, que implica el desarrollo autónomo de múltiples embriones de origen nucelar, además del embrión cigótico o sexual, en una misma semilla. El objetivo de esta investigación fue estimar el número potencial de embriones por semilla, el porcentaje de semillas poliembriónicas y el nivel de poliembrionía en las variedades ‘’Colimex’’ y ‘’Lise’’ de lima mexicana o limón mexicano (Citrus aurantifolia), y la variedad ‘’Rosenberger’’ de limón verdadero (C. limon). Se utilizó el método de conteo directo de embriones extraídos de semillas maduras obtenidas de frutos que aún tenían cáscara verde. Las variedades ‘’Colimex’’ y ‘’Lise’’ presentaron 80.65 y 78.27 % respectivamente, de semillas con dos o más embriones, resultando en un alto nivel de poliembrionía, mientras que ‘’Rosenberger’’, con 18.37 %, fue ligeramente poliembriónica.

Kinases in Regulation of Anther and Pollen Development

2025-06-13

Shivam Sharma , Sanjay Kapoor , Akhilesh K. Tyagi | Critical Reviews in Plant Sciences

PpSKα boosts chilling tolerance by activating PpTrxh9 in peach fruit

2025-06-13

Caifeng Jiao , Jing Sun | Frontiers in Plant Science

Introduction The cold chain system is extensively used to lower the quality deterioration in postharvest fruits. However, the occurrence of chilling injury (CI) is a common phenomenon in peach fruits, … Introduction The cold chain system is extensively used to lower the quality deterioration in postharvest fruits. However, the occurrence of chilling injury (CI) is a common phenomenon in peach fruits, consequently compromising their market value. Methods and results Cold tolerance was boosted by glycine betaine (GB) supplementation. GB treatment promoted the thioredoxin h9 (PpTrxh9) expression and ameliorated oxidative injury. Using assays such as yeast two-hybrid, co-immunoprecipitation, pull-down, and bimolecular fluorescence complementation, SHAGGY-related protein kinase a (PpSKa) was verified as a protein interacting with PpTrxh9. GB treatment elevated the PpSKa expression. The overexpression of PpSKa in tomato fruits decreased the cold sensitivity and oxidative damage, whereas virus-induced gene silencing of PpSKa in peach fruits aggravated the CI progression and oxidative damage. PpSKa was found to phosphorylate PpTrxh9 in the kinase assay. Moreover, PpSKa-overexpressed tomato fruits exhibited higher SlTrxh9 expression, whereas the PpSKa-RNAi peach fruit exhibited lower PpTrxh9 expression. Discussion Taken together, PpSKa decreased the development of CI by improving the expression of PpTrxh9 in peach fruits.

Heterologous Expression and Antimicrobial Mechanism of a Cysteine-Rich Peptide from Barnacle Pollicipes pollicipes

2025-06-13

Zhicheng He , Zelin Fei , Huiting Shi +5 more | Microorganisms

The escalating crisis of antimicrobial resistance in aquaculture, driven by the indiscriminate use of antibiotics, underscores the urgent need to develop novel anti-infective agents. This study addresses this requirement by … The escalating crisis of antimicrobial resistance in aquaculture, driven by the indiscriminate use of antibiotics, underscores the urgent need to develop novel anti-infective agents. This study addresses this requirement by investigating cysteine-rich antimicrobial peptides (AMPs) in understudied crustacean species. A cysteine-rich AMP, designated PpRcys1, was identified and characterized from the genome of Pollicipes pollicipes. PpRcys1 comprises 104 amino acids, with 85 residues forming the mature peptide region, and exhibits random coils, a CSαβ-fold, and one β-sheet. Our findings demonstrated that recombinant PpRcys1 (rPpRcys1) possesses broad-spectrum antimicrobial activity against three Gram-positive bacteria (Staphylococcus aureus, Bacillus sp. T2, and Streptococcus agalactiae) and four Gram-negative bacteria (Aeromonas hydrophila, Escherichia coli, Vibrio alginolyticus, and Acinetobacter sp. L3), with minimum inhibitory concentrations ranging from 8 to 32 μM. It exerts antimicrobial effects by inducing membrane disruption without impacting bacterial protease activity, DNA migration, or respiratory chain reductase activity. Further investigation is warranted to determine whether it can target and interfere with intracellular bacterial processes. Our discovery and characterization of this novel AMP provide a promising foundation for its development as an alternative to antibiotics.

A highly screening system at seedling-stage for genic male sterility in pepper hybrid breeding

2025-06-12

Pan luzhao , Jin Wang , Peng Tang +7 more | Research Square (Research Square)

<title>Abstract</title> In pepper (<italic>Capsicum annuum</italic> L.), utilizing heterosis is a highly effective strategy to boost yield. While GMS lines offer advantages for seed production by avoiding the limitations associated with … <title>Abstract</title> In pepper (<italic>Capsicum annuum</italic> L.), utilizing heterosis is a highly effective strategy to boost yield. While GMS lines offer advantages for seed production by avoiding the limitations associated with cytoplasmic male sterile (CMS) lines, the use of GMS typically requires the labor-intensive removal of 50% of fertile plants during seed production. To address this challenge, we identified a <italic>anthocyanidin-absent (aa)</italic> mutant, with a green hypocotyl at seedling stage and yellow anthers.We further identified dihydroflavonol 4-reductase gene (<italic>CaDFR)</italic> as a key gene regulating anthocyanin biosynthesis in pepper based on gene fine localization and VIGS experiments. Genetic segregation analysis revealed that <italic>CaDFR</italic> and <italic>CaDYT1</italic> (a genic male sterile gene) had a closely linkage relationship. Building on this discovery, we developed an efficient hybrid seed production strategy using the green hypocotyl morphological marker from the <italic>aa</italic> mutant and the male sterile line <italic>gms1</italic> (<italic>CaDYT1</italic> locus). In conclusion, we successfully cloned <italic>CaDFR</italic>, a key gene controlling hypocotyl and anther color in pepper. Additionally, we further proposed an efficient seed propagation strategy to accelerate hybrid seed production in the utilization of heterosis. This study not only deepens mechanistic insights into the genetic regulation of pepper pigmentation, but also establishes a practical framework for optimizing hybrid breeding protocols, thereby contributing to simplifying the pepper breeding process and sustainable cultivation.

Conflicting selection on flowering time

2025-06-09

Tegan Armarego‐Marriott | Nature Climate Change

Genetic composition and heterozygosity of gibberellin-induced 2n gametes evaluated by SSR markers in Populus

2025-06-07

Yifan Zhao , Yunyun Xie , Bo Kong +7 more | BMC Plant Biology

The artificial induction of unreduced (2n) gametes, due to first division restitution (FDR) or second division restitution (SDR), is an important method to produce triploids in higher plants. It is … The artificial induction of unreduced (2n) gametes, due to first division restitution (FDR) or second division restitution (SDR), is an important method to produce triploids in higher plants. It is crucial to evaluate the genetic composition and heterozygosity transmission of induced 2n gametes with different formation mechanisms. Here, we produced 110 triploids by pollinating the female inflorescence of Populus alba × P. glandulosa with gibberellin-induced 2n pollen of Populus bolleana. The genetic composition and heterozygosity of the induced 2n pollen were inferred from SSR marker analysis of the triploid offspring, using 27 primer pairs distributed across nine Populus chromosomes. This revealed that, among the 110 hybrid triploids, 70 triploids did originate from FDR-type 2n pollen and the other 40 from SDR-type 2n pollen. The FDR-type and SDR-type 2n pollen transmitted a substantially different level of parental heterozygosity (0.7545 and 0.3167, respectively) in P. bolleana. Additionally, compared with the low coefficient of variation (CV = 12.82%) for heterozygosity transmitted by FDR-type 2n pollen, there was much higher coefficient of variation (CV = 48.82%) for that transmitted by SDR-type 2n pollen. Our findings provide a valuable reference point for bolstering suitable applications of 2n gametes in future research, and can help foster new strategies of triploid breeding in plants. Not applicable.

Genome-wide identification of the RALF gene family in Camellia oleifera Abel. and the potentiality of CoRALF50 in pollen tube growth

2025-06-06

Mengqi Lu , Junqin Zhou , Yiyang Gu +4 more | Plant Science