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1.
BMC Plant Biol ; 19(1): 304, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291882

RESUMO

BACKGROUND: In flowering plants, proper seed development is achieved through the constant interplay of fertilization products, embryo and endosperm, and maternal tissues. Communication between these compartments is supposed to be tightly regulated at their interfaces. Here, we characterize the deposition pattern of an apoplastic lipid barrier between the maternal inner integument and fertilization products in Arabidopsis thaliana seeds. RESULTS: We demonstrate that an apoplastic lipid barrier is first deposited by the ovule inner integument and undergoes de novo cutin deposition following central cell fertilization and relief of the FERTILIZATION INDEPENDENT SEED Polycomb group repressive mechanism. In addition, we show that the WIP zinc-finger TRANSPARENT TESTA 1 and the MADS-Box TRANSPARENT TESTA 16 transcription factors act maternally to promote its deposition by regulating cuticle biosynthetic pathways. Finally, mutant analyses indicate that this apoplastic barrier allows correct embryo sliding along the seed coat. CONCLUSIONS: Our results revealed that the deposition of a cutin apoplastic barrier between seed maternal and zygotic tissues is part of the seed coat developmental program.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Lipídeos de Membrana/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Endosperma/genética , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
2.
Planta ; 250(2): 657-665, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31147828

RESUMO

MAIN CONCLUSION: The grapevine VvßVPE promoter is specifically expressed in the seed. The - 1306~- 1045 bp core region restricts expression in other tissues and organs. Vacuolar processing enzyme (VPE) is a cysteine proteinase regulating vacuolar protein maturation and executing programmed cell death (PCD) in plants. Vitis vinifera (Vv)ßVPE is a ß-type VPE showing seed-specific expression that processes seed proteins during ovule development. However, the regulation of the seed-specific gene expression is far from understood. In this study, we characterize VvßVPE promoter (pVvßVPE) from 12 seeded and seedless grape genotypes. 94.56% of the pVvßVPE coding sequence is consistent. Two ßVPE promoters were constructed and transformed into Arabidopsis thaliana via ß-glucuronidase (GUS) fused expression vectors, using cv. Pinot Noir and cv. Thompson as seed and seedless candidates. GUS staining in different tissues and organs revealed that VvßVPE expresses specifically in the embryo, including the cotyledon, hypocotyl and suspensor, but not in the leaf, stem, root or flowers of the seedling. Using promoter deletion analysis, we created four incomplete VvßVPE promoters and found each pVvßVPE deletion could drive GUS gene to express in seeds. Interestingly, seed specificity disappeared when the promoter missed the core - 1306~- 1045 bp region. All deletion promoters presenting various quantified GUS activities indicate that the region - 1704~- 1306 bp inhibits, and the region - 705~- 861 bp promotes gene expression of VvßVPE. Our results demonstrate that pVvßVPE is a seed-specific promoter in both seeded and seedless grapes. Moreover, the core region of pVvßVPE (- 1306~- 1045 bp) is the key one responsible for seed-specific expression.


Assuntos
Cisteína Endopeptidases/genética , Regiões Promotoras Genéticas/genética , Sementes/genética , Vitis/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Genes Reporter , Especificidade de Órgãos , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Plântula/genética , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Vitis/crescimento & desenvolvimento
3.
BMC Genomics ; 20(1): 421, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138116

RESUMO

BACKGROUND: Cotton is the most essential textile crop worldwide, and phytohormones are critical for cotton fiber development. One example is the role of auxin in fiber initiation, but we know little molecular basis. MicroRNAs (miRNAs) have a significant function in cotton development; nevertheless their role in fiber initiation remains unclear. Here, exogenous IAA was applied to cotton plant before anthesis. Utilizing small RNA sequencing, the mechanism underlying miRNA-mediated regulation of fiber initiation under exogenous IAA treatment was investigated. RESULTS: With exogenous IAA application, the endogenous IAA and GA contents of IAA treated (IT) ovules were higher than control (CK) ovules at the fiber initiation stage, while endogenous ABA content was lower in IT than CK. Using scanning electron microscopy, we found the fiber number and size were significantly promoted in IT at 0 DPA. Fiber quality analysis showed that fiber length, uniformity, strength, elongation, and micronaire of IT were higher than CK, though not statistically significant, while lint percent was significantly higher in IT. We generated six small RNA libraries using - 3, 0, and 3 DPA ovules of IT and CK, and identified 58 known miRNAs and 83 novel miRNAs together with the target genes. The differential expressed miRNAs number between IT and CK at - 3, 0, 3 DPA was 34, 16 and 24, respectively. Gene ontology and KEGG pathway enrichment analyses for the target genes of the miRNAs expressed in a differential manner showed that they were significantly enriched in 30 terms and 8 pathways. QRT-PCR for those identified miRNAs and the target genes related to phytohormones and fiber development was performed, and results suggested a potential role of these miRNAs in fiber initiation. CONCLUSIONS: The exogenous IAA application affected the relative phytohormone contents in ovule and promoted fiber initiation in cotton. Identification and profiling of miRNAs and their targets at the fiber initiation stage provided insights for miRNAs' regulation function of fiber initiation. These findings not only shed light on the regulatory network of fiber growth but also offer clues for cotton fiber amelioration strategies in cotton.


Assuntos
Gossypium/genética , Ácidos Indolacéticos/farmacologia , MicroRNAs/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Perfilação da Expressão Gênica , Genes de Plantas , Gossypium/efeitos dos fármacos , Gossypium/crescimento & desenvolvimento , Gossypium/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Óvulo Vegetal/efeitos dos fármacos , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/ultraestrutura , Reguladores de Crescimento de Planta/metabolismo , Análise de Sequência de RNA
4.
Genes (Basel) ; 10(5)2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31075950

RESUMO

Histone acts as the core for nucleosomes and is a key protein component of chromatin. Among different histone variants, histone H3 (HH3) variants have been reported to play vital roles in plant development. However, biological information and evolutionary relationships of HH3 genes in cotton remain to be elucidated. The current study identified 34 HH3 genes in Gossypium hirsutum. Phylogenetic analysis classified HH3 genes of 19 plant species into eight distinct clades. Sequence logos analysis among Arabidopsis, rice, and G. hirsutum amino acid residues showed higher conservation in amino acids. Using collinearity analysis, we identified 81 orthologous/paralogous gene pairs among the four genomes (A, D, At, and Dt) of cotton. Further, orthologous/paralogous and the Ka/Ks ratio demonstrated that cotton HH3 genes experienced strong purifying selection pressure with restricted functional divergence resulting from segmental and whole genome duplication. Expression pattern analysis indicated that GhHH3 genes were preferentially expressed in cotton ovule tissues. Additionally, GhHH3 gene expression can be regulated by abiotic stresses (cold, heat, sodium chloride (NaCl), and polyethylene glycol (PEG)) and phytohormonal (brassinolide (BL), gibberellic acid (GA), indole-3-acetic acid (IAA), salicylic acid (SA), and methyl jasmonate (MeJA)) treatments, suggesting that GhHH3 genes might play roles in abiotic and hormone stress resistance. Taken together, this work provides important information to decipher complete molecular and physiological functions of HH3 genes in cotton.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Gossypium/genética , Histonas/genética , Óvulo Vegetal/genética , Estresse Fisiológico/genética , Óvulo Vegetal/crescimento & desenvolvimento
5.
BMC Plant Biol ; 19(1): 202, 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31096905

RESUMO

BACKGROUND: The Fertilization-related kinases (FRK) form a class that belongs to the MEKK subfamily of plant MAPKKKs. It was recently shown that FRK class kinases expanded during angiosperm evolution, reaching their maximum numbers in the lineage leading to solanaceous species and culminating in the Solanum genus where they account for more than 40% of the total MEKKs. The first members studied, ScFRK1 and ScFRK2 were shown to play a pivotal role in gametophyte development in the wild potato species Solanum chacoense. RESULTS: ScFRK3 is also involved in gametophyte development. ScFRK3 is expressed in developing pollen and young ovules, reaching its highest level immediately after meiosis and during the mitosis steps in both gametophytes. Hence, three independent lines of ScFRK3 RNAi mutant plants showed decreased number of seeds per fruit. We also observed an important number of degenerated embryo sac in mature ovary. Analysis of ovule development showed that most embryo sac did not enter mitosis I in ScFRK3 RNAi mutant plants. Severe lethality was also observed during male gametophyte development, pollen being arrested before mitosis I, as observed in the female gametophyte. Obvious defects in vegetative organs were not observed, emphasizing the reproductive roles of the FRK class kinases. To isolate MAP kinases acting downstream of ScFRK3, a de novo S. chacoense transcriptome from male and female reproductive organs was assembled. Of the five ScMKKs and 16 ScMPKs retrieved, only the ScMKK3 interacted with ScFRK3, while only the ScMPK13 interacted with ScMKK3, leading to an apparent single three-tiered canonical MAP kinase cascade combination involving ScFRK3-ScMKK3-ScMPK13. CONCLUSIONS: The ScFRK3 MAPKKK is involved in a signaling cascade that regulates both male and female gamete development, and most probably act upstream of ScMKK3 and ScMPK13.


Assuntos
Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Proteínas Quinases/metabolismo , Solanum/crescimento & desenvolvimento , Hibridização In Situ , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Proteínas Quinases/genética , Proteínas Quinases/fisiologia , RNA de Plantas/metabolismo , Solanum/enzimologia , Solanum/genética , Técnicas do Sistema de Duplo-Híbrido
6.
Plant Reprod ; 32(3): 323-330, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31115664

RESUMO

KEY MESSAGE: The developmental morphology of male and female kiwifruit flowers is tracked to delimit a framework of events to aid the study of divergence in floral gene expression. The transition from hermaphrodite to unisexual development of kiwifruit (Actinidia chinensis Planch) flowers has been reported previously, but differences in gene expression controlling sexual development for this species have not been associated with the major developmental changes occurring within pistils. We investigated the key stages in male and female flower development to define the point at which meristematic activities diverge in the two sexes. A combination of scanning electron microscopy and light microscopy was used to investigate pistil development from the earliest stages. We identified seven distinct stages characterized by differences in ovary size and shape, macrosporogenesis, ovule primordium development, anther locule lengthening, microspore wall thickening, and pollen degeneration. Sex differences were evident from the initial stage of development, with a laterally compacted gynoecium in male flowers. However, the key developmental stage, at which tissue differentiation clearly deviated between the two sexes, was stage 3, when flowers were 3.5 to 4.5 mm in length at approximately 10 d from initiation of stamen development. At this stage, male flowers lacked evident carpel meristem development as denoted by a lack of ovule primordium formation. Pollen degeneration in female flowers, probably driven by programmed cell death, occurred at the late stage 6, while the final stage 7 was represented by pollen release. As the seven developmental stages are associated with specific morphological differences, including flower size, the scheme suggested here can provide the required framework for the future study of gene expression during the regulation of flower development in this crop species.


Assuntos
Actinidia/crescimento & desenvolvimento , Flores/crescimento & desenvolvimento , Actinidia/genética , Actinidia/ultraestrutura , Flores/genética , Flores/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/ultraestrutura , Microscopia Eletrônica de Varredura , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/ultraestrutura , Pólen/genética , Pólen/crescimento & desenvolvimento , Pólen/ultraestrutura , Reprodução
7.
Plant Reprod ; 32(3): 257-273, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30852671

RESUMO

KEY MESSAGE: PCD role in unisexual flowers. The developmental processes underlying the transition from hermaphroditism to unisexuality are key to understanding variation and evolution of floral structure and function. A detailed examination of the cytological and histological patterns involved in pollen and ovule development of staminate and pistillate flowers in the dioecious Opuntia robusta was undertaken, and the potential involvement of programmed cell death in the abortion of the sex whorls was explored. Flowers initiated development as hermaphrodites and became functionally unisexual by anthesis. Female individuals have pistillate flowers with a conspicuous stigma, functional ovary, collapsed stamens and no pollen grains. Male individuals have staminate flowers, with large yellow anthers, abundant pollen grains, underdeveloped stigma, style and an ovary that rarely produced ovules. In pistillate flowers, anther abortion resulted from the premature degradation of the tapetum by PCD, followed by irregular deposition of callose wall around the microsporocytes, and finally by microspore degradation. In staminate flowers, the stigma could support pollen germination; however, the ovaries were reduced, with evidence of placental arrest and ovule abortion through PCD, when ovules were present. We demonstrate that PCD is recruited in both pistillate and staminate flower development; however, it occurs at different times of floral development. This study contributes to the understanding of the nature of the O. robusta breeding system and identifies developmental landmarks that contribute to sexual determination in Cactaceae.


Assuntos
Apoptose , Opuntia/crescimento & desenvolvimento , Infertilidade das Plantas , Flores/crescimento & desenvolvimento , Flores/fisiologia , Opuntia/fisiologia , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/fisiologia , Melhoramento Vegetal , Pólen/crescimento & desenvolvimento , Pólen/fisiologia , Polinização , Reprodução
8.
PLoS Genet ; 15(2): e1007934, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30742622

RESUMO

Ovules contain the female gametophytes which are fertilized during pollination to initiate seed development. Thus, the number of ovules that are produced during flower development is an important determinant of seed crop yield and plant fitness. Mutants with pleiotropic effects on development often alter the number of ovules, but specific regulators of ovule number have been difficult to identify in traditional mutant screens. We used natural variation in Arabidopsis accessions to identify new genes involved in the regulation of ovule number. The ovule numbers per flower of 189 Arabidopsis accessions were determined and found to have broad phenotypic variation that ranged from 39 ovules to 84 ovules per pistil. Genome-Wide Association tests revealed several genomic regions that are associated with ovule number. T-DNA insertion lines in candidate genes from the most significantly associated loci were screened for ovule number phenotypes. The NEW ENHANCER of ROOT DWARFISM (NERD1) gene was found to have pleiotropic effects on plant fertility that include regulation of ovule number and both male and female gametophyte development. Overexpression of NERD1 increased ovule number per fruit in a background-dependent manner and more than doubled the total number of flowers produced in all backgrounds tested, indicating that manipulation of NERD1 levels can be used to increase plant productivity.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Arabidopsis/fisiologia , Genes de Plantas , Óvulo Vegetal/genética , Arabidopsis/crescimento & desenvolvimento , Contagem de Células , Fertilidade/genética , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Variação Genética , Estudo de Associação Genômica Ampla , Óvulo Vegetal/citologia , Óvulo Vegetal/crescimento & desenvolvimento , Filogenia , Plantas Geneticamente Modificadas , Polinização/genética , Polimorfismo de Nucleotídeo Único
9.
Protoplasma ; 256(4): 909-922, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30675653

RESUMO

Arabinogalactan proteins (AGPs) are hyperglycosylated members of the hydroxyproline-rich glycoprotein (HRGP) superfamily and are widely distributed throughout the plant kingdom. In Oryza sativa (rice), the gene expression and biological function of AGPs only have received minimal research attention. Here, we used qRT-PCR to detect the expression patterns of OsAGP genes in various organs, and found that six genes were preferentially expressed in panicles, three genes were specifically expressed in anthers, and one gene in the stigma. Furthermore, using four specific monoclonal antibodies (JIM8, JIM13, LM2, MAC207), we observed the distribution of AGPs in rice anthers, ovules, and embryos. In anthers, the strong fluorescence signals of AGPs were present in tapetum cells, pollen mother cells, and mature pollens, suggesting that AGPs might be related to the development of anther and pollen. In ovules, signals of AGPs were specifically distributed in the three micropylar megaspores of the tetrad, and with intense signals in the egg cell and synergid cells in the mature embryo sac. This suggests that AGPs may be involved in megaspore determination and double fertilization. In embryos, the immunological signals of AGPs appeared in peripheral and inner cells at the early stage, and in the scutellum, plumule, and radicle at the late stage, indicating that AGPs may be associated with organ differentiation and maturation of embryos. In this study, we revealed that AGPs were widely distributed in rice anthers, ovules, and embryos, which lays a foundation for the functional investigation of AGPs in various processes of sexual reproduction.


Assuntos
Flores/genética , Mucoproteínas/genética , Mucoproteínas/metabolismo , Oryza/crescimento & desenvolvimento , Óvulo Vegetal/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
10.
BMC Genomics ; 20(1): 90, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691391

RESUMO

BACKGROUND: As important female reproductive tissues, the rice (Oryza sativa L.) ovule and female gametophyte is significant in terms of their fertility. Long noncoding RNAs (lncRNAs) play important and wide-ranging roles in the growth and development of plants and have become a major research focus in recent years. Therefore, we explored the characterization and expression change of lncRNAs during ovule development and female gametophytic abortion. RESULTS: In our study, whole-transcriptome strand-specific RNA sequencing (ssRNA-seq) was performed in the ovules of a high-frequency female-sterile rice line (fsv1) and a wild-type rice line (Gui99) at the megaspore mother cell meiosis stage (stage 1), functional megaspore mitosis stage (stage 2) and female gametophyte mature stage (stage 3). By comparing two rice lines, we identified 152, 233, and 197 differentially expressed lncRNAs at the three ovule developmental stages. Functional analysis of the coherent target genes of these differentially expressed lncRNAs indicated that many lncRNAs participate in multiple pathways such as hormone and cellular metabolism and signal transduction. Moreover, there were many differentially expressed lncRNAs acting as the precursors of some miRNAs that are involved in the development of ovules and female gametophytes. In addition, we have found that lncRNAs can act as decoys, competing with mRNAs for binding to miRNAs to maintain the normal expression of genes related to ovule and female gametophyte development. CONCLUSION: These results provide important clues for elucidating the female gametophyte abortion mechanism in rice. This study also expands our understanding about the biological functions of lncRNAs and the annotation of the rice genome.


Assuntos
Regulação da Expressão Gênica de Plantas , Células Germinativas Vegetais/metabolismo , Oryza/genética , Óvulo Vegetal/genética , RNA Longo não Codificante/metabolismo , Perfilação da Expressão Gênica , Genoma de Planta , Sequenciamento de Nucleotídeos em Larga Escala , MicroRNAs/química , MicroRNAs/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Precursores de RNA/química , Precursores de RNA/metabolismo , RNA Longo não Codificante/química , RNA Longo não Codificante/fisiologia , RNA Mensageiro/metabolismo , Análise de Sequência de RNA
11.
Plant Physiol ; 179(3): 1080-1092, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30659067

RESUMO

Ovule development is critical for seed development and plant reproduction. Multiple transcription factors (TFs) have been reported to mediate ovule development. However, it is not clear which intracellular components regulate these TFs during ovule development. After their synthesis, TFs are transported into the nucleus a process regulated by karyopherins commonly known as importin alpha and ß. Around half of Arabidopsis (Arabidopsis thaliana) importin ß-coding genes have been functionally characterized but only two with specific cargos have been identified. We report here that Arabidopsis IMPORTIN ß4 (IMB4) regulates ovule development through nucleocytoplasmic transport of transcriptional coactivator growth regulating factors-interacting factors (GIFs). Mutations in IMB4 impaired ovule development by affecting integument growth. imb4 mutants were also defective in embryo sac development, leading to partial female sterility. IMB4 directly interacts with GIFs and is critical for the nucleocytoplasmic transport of GIF1. Finally, functional loss of GIFs resulted in ovule defects similar to those in imb4 mutants, whereas enhanced expression of GIF1 partially restored the fertility of imb4 The results presented here uncover a novel genetic pathway regulating ovule development and reveal the upstream regulator of GIFs.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Transporte Ativo do Núcleo Celular , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Núcleo Celular/metabolismo , Citocininas/metabolismo , Citoplasma/metabolismo , Ácidos Indolacéticos/metabolismo , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/metabolismo , Transativadores/metabolismo
12.
Curr Top Dev Biol ; 131: 373-399, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30612624

RESUMO

Ovules are the precursors to seeds and as such are critical to plant propagation and food production. Mutant studies have led to the identification of numerous genes regulating ovule development. Genes encoding transcription factors have been shown to direct ovule spacing, ovule identity and integument formation. Particular co-regulators have now been associated with activities of some of these transcription factors, and other protein families including cell surface receptors have been shown to regulate ovule development. Hormone levels and transport, especially of auxin, have also been shown to play critical roles in ovule emergence and morphogenesis and to interact with the transcriptional regulators. Ovule diversification has been studied using orthologs of regulatory genes in divergent angiosperm groups. Combining modern genetic evidence with expanding knowledge of the fossil record illuminates the possible origin of the unique bitegmic ovules of angiosperms.


Assuntos
Evolução Biológica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Magnoliopsida/crescimento & desenvolvimento , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Magnoliopsida/genética , Óvulo Vegetal/genética
13.
Curr Top Dev Biol ; 131: 401-434, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30612625

RESUMO

Flowering plants constitute an indispensable basis for the existence of most organisms, including humans. In a world characterized by rapid population growth and climate changes, understanding plant reproduction becomes increasingly important in order to respond to the resource shortage associated with this development. New technologies enabling powerful forward genetic approaches, comprehensive genome and transcriptome analyses, and sophisticated cell isolation and imaging have advanced our understanding of the molecular mechanisms underlying gamete formation and fertilization. In addition, these techniques have allowed us to explore the fascinating cellular crosstalk, which coordinates the intra- and interorganismic interactions that secure reproductive success. Here we review the basic principles underlying development of the germ cell-harboring female gametophyte in flowering plants. We start with the selection of the founder cells and end with the formation of a few-celled, highly specialized structure that operates on the basis of division of labor in order to generate the next generation.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Magnoliopsida/crescimento & desenvolvimento , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Magnoliopsida/genética , Óvulo Vegetal/genética
14.
Plant Biol (Stuttg) ; 21(4): 571-584, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30468551

RESUMO

The prevention of Botrytis cinerea infection and the study of grape seedlessness are very important for grape industries. Finding correlated regulatory genes is an important approach towards understanding their molecular mechanisms. Ethylene responsive factor (ERF) gene family play critical roles in defence networks and the growth of plants. To date, no large-scale study of the ERF proteins associated with pathogen defence and ovule development has been performed in grape (Vitis vinifera L.). In the present study, we identified 113 ERF genes (VvERF) and named them based on their chromosome locations. The ERF genes could be divided into 11 groups based on a multiple sequence alignment and a phylogenetic comparison with homologues from Arabidopsis thaliana. Synteny analysis and Ka/Ks ratio calculation suggested that segmental and tandem duplications contributed to the expansion of the ERF gene family. The evolutionary relationships between the VvERF genes were investigated by exon-intron structure characterisation, and an analysis of the cis-acting regulatory elements in their promoters suggested potential regulation after stress or hormone treatments. Expression profiling after infection with the fungus, B. cinerea, indicated that ERF genes function in responses to pathogen attack. In addition, the expression levels of most ERF genes were much higher during ovule development in seedless grapes, suggesting a role in ovule abortion related to seedlessness. Taken together, these results indicate that VvERF proteins are involved in responses to Botrytis cinerea infection and in grape ovule development. This information may help guide strategies to improve grape production.


Assuntos
Botrytis , Etilenos/metabolismo , Genes de Plantas/genética , Óvulo Vegetal/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Vitis/genética , Arabidopsis/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/fisiologia , Estudo de Associação Genômica Ampla , Filogenia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/fisiologia , Alinhamento de Sequência , Sintenia/genética , Transcriptoma , Vitis/crescimento & desenvolvimento , Vitis/microbiologia , Vitis/fisiologia
15.
Plant Physiol Biochem ; 135: 9-18, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30496891

RESUMO

Arabinogalactan proteins (AGPs), i.e. a subfamily of hydroxyproline-rich proteins (HRGPs), are widely distributed in the plant kingdom. For many years, AGPs have been connected with the multiple phases of plant reproduction and developmental processes. Currently, extensive knowledge is available about their various functions, i.e. involvement in pollen grain formation, initiation of pollen grain germination, pollen tube guidance in the transmission tissue of pistil and ovule nucellus, and function as a signaling molecule during cell-cell communication. Although many studies have been performed, the mechanism of action, the heterogeneous molecule structure, and the connection with other extracellular matrix components have not been sufficiently explained. The aim of this work was to gather and describe the most important information on the distribution of AGPs in gametophyte development. The present review provides a summary of the first reports about AGPs and the most recent knowledge about their functions during male and female gametophyte formation.


Assuntos
Mucoproteínas/metabolismo , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Mucoproteínas/fisiologia , Óvulo Vegetal/metabolismo , Proteínas de Plantas/fisiologia , Pólen/metabolismo
16.
J Exp Bot ; 69(21): 5169-5176, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30312436

RESUMO

Seeds derive from ovules upon fertilization and therefore the total number of ovules determines the final seed yield, a fundamental trait in crop plants. Among the factors that co-ordinate the process of ovule formation, the transcription factors CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 and the hormone cytokinin (CK) have a particularly prominent role. Indeed, the absence of both CUC1 and CUC2 causes a severe reduction in ovule number, a phenotype that can be rescued by CK treatment. In this study, we combined CK quantification with an integrative genome-wide target identification approach to select Arabidopsis genes regulated by CUCs that are also involved in CK metabolism. We focused our attention on the functional characterization of UDP-GLUCOSYL TRANSFERASE 85A3 (UGT85A3) and UGT73C1, which are up-regulated in the absence of CUC1 and CUC2 and encode enzymes able to catalyse CK inactivation by O-glucosylation. Our results demonstrate a role for these UGTs as a link between CUCs and CK homeostasis, and highlight the importance of CUCs and CKs in the determination of seed yield.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Citocininas/metabolismo , Óvulo Vegetal/crescimento & desenvolvimento , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Homeostase
17.
Planta ; 248(5): 1331-1337, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30209619

RESUMO

MAIN CONCLUSION: Transcription of soybean retrotransposon SORE-1 was temporally upregulated during ovule development. This transcriptional pattern was under intrinsic control conferred by the long terminal repeat of SORE-1. Transcriptionally active retrotransposons are capable of inducing random disruption of genes, providing a powerful tool for mutagenesis. Activation of retrotransposons in reproductive cells, in particular, can lead to heritable changes. Here, we examined developmental control of transcription of soybean retrotransposon SORE-1. Transgenic Arabidopsis plants that contain ß-glucuronidase (GUS) reporter gene fused with the SORE-1 long terminal repeat (LTR) had GUS staining in the ovule. Quantitative analysis of transcripts in plants with this DNA construct and those with the full-length SORE-1 element indicated a temporal upregulation of SORE-1 transcription during ovule development. A comparable phenomenon was also observed in soybean plants that had a recent insertion of this element in the GmphyA2 gene. These results provide evidence that the temporal upregulation of SORE-1 in the reproductive organ is sufficiently controlled by its LTR and indicate that the intrinsic expression pattern of SORE-1 is consistent with its mutagenic property.


Assuntos
Regulação da Expressão Gênica de Plantas , Óvulo Vegetal/metabolismo , Retroelementos , Soja/metabolismo , Arabidopsis , Óvulo Vegetal/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Soja/crescimento & desenvolvimento , Sequências Repetidas Terminais , Regulação para Cima
18.
Biochem Biophys Res Commun ; 505(1): 176-180, 2018 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-30243715

RESUMO

Protein phosphatase 2A (PP2A) is a heterotrimeric protein complex conserved among eukaryotes. The B subunit of PP2A determines the substrate specificity of the PP2A holoenzyme, and is classified into the B, B', B″ and B‴ families. Arabidopsis thaliana has two isoforms of the B-family subunit (ATBA and ATBB). A double knockout of their genes is lethal, but which developmental process is primarily impaired by the double knockout is unclear. Identifying such a process helps understand PP2A-mediated signaling more deeply. Here, genetic characterization of new knockout mutants for these genes shows that they are necessary for pollen development but not for female gametophyte development. Compared to wild-type pollen grains, the mutant pollen grains exhibited lower enzyme activities, germinated less frequently on stigmas, and exhibited the aberrant numbers of sperm cell nuclei, suggesting that ATBA and ATBB play pleiotropic roles in pollen development. The amino acids stabilizing the interaction between the human PP2A A and B-family subunits are conserved in an Arabidopsis A subunit (AtPP2AA2), ATBA and ATBB. His-tagged AtPP2AA2 co-immunoprecipitated with either Myc-tagged ATBA or Myc-tagged ATBB in vitro, confirming their interactions. Proteins that regulate pollen development and that undergo dephosphorylation are likely primary targets of ATBA and ATBB.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Isoenzimas/metabolismo , Óvulo Vegetal/metabolismo , Pólen/metabolismo , Proteína Fosfatase 2/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Isoenzimas/genética , Mutação , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Pólen/genética , Pólen/crescimento & desenvolvimento , Ligação Proteica , Proteína Fosfatase 2/genética
19.
Plant Sci ; 274: 420-431, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30080630

RESUMO

Vacuolar processing enzymes (VPEs), belonging to cysteine protease, are responsible for processing seed protein during maturation. Stenospermocarpic grapes occur self-abortion in fertilized embryos during the ovule development, which affects the formation of matured seed proteins. However, little is known about VPE functions in ovule self-defeating. Here, we investigated the role of one seed-type VPE gene, VvßVPE. Sequence analysis showed that all ORFs (Open reading frames) of VvßVPE from 19 seed/seedless genotypes are highly conserved. At the transcriptional level, VvßVPE was specifically expressed during ovule development, with distinct expression patterns: it increased gradually in seeded grapes; while weakly expressed in seedless grapes. Whereas, at the translational level, 3 forms of VvßVPE were expressed during ovule development in seeded grape: precursor ßVPE (pßVPE), intermediate ßVPE (ißVPE) and finally, active mature ßVPE (mßVPE). By contrast, in seedless grape, VvßVPE only exists as pßVPE at whole developmental stage of ovule. for confirming these expression patterns, 12 seeded/seedless genotypes were sampled and analyzed. Furthermore, VPE enzyme activity was increased in Arabidopsis overexpressing VvßVPE, leading to faster germination. Our study indicated that VvßVPE is essential for grapevine ovule maturation through various forms and is involved in seed germination.


Assuntos
Cisteína Endopeptidases/metabolismo , Vitis/enzimologia , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Cisteína Endopeptidases/genética , Germinação , Óvulo Vegetal/enzimologia , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Vitis/genética , Vitis/crescimento & desenvolvimento , Vitis/fisiologia
20.
J Plant Physiol ; 230: 1-12, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30134217

RESUMO

Ovule and seed development in plants has long fascinated the scientific community given the complex cell coordination implicated in these processes. These cell events are highly conserved but are not necessarily representative of all plants. In this study, with the aim of obtaining information regarding the cellular patterns that follow the usual development of the ovule and the zygotic embryo, we carried out an integral anatomical study of the Capsicum chinense Jacq., floral buds and seeds at various days during maturation. This study allowed us to identify the main histo-morphological stages accompanying the transition of somatic cells into the macrospore, female gamete, and the zygotic embryogenesis. This knowledge is fundamental for future biotechnological research focused on solving the morphological recalcitrance observed during the in vitro induction of somatic or microspore embryogenesis in Capsicum. For the first time in C. chinense, we have described the hypostases, a putative source of plant growth regulators, and "the corrosion cavity", a space around the embryo. Additionally, the cell wall pectin-esterification status was investigated by immunohistology. At early stages of morphogenesis, the pectin is highly methyl-esterified; however, methyl-esterification decreases gradually throughout the process. A comparison of the results obtained here, together with the histo- and immunological changes occurring during the somatic and microspore embryogenesis, should help to elucidate the biochemical mechanisms that trigger the morphogenic events in Capsicum spp.


Assuntos
Capsicum/crescimento & desenvolvimento , Óvulo Vegetal/crescimento & desenvolvimento , Pectinas/metabolismo , Sementes/crescimento & desenvolvimento , Capsicum/anatomia & histologia , Capsicum/metabolismo , Esterificação , Flores/anatomia & histologia , Flores/crescimento & desenvolvimento , Flores/metabolismo , Imunofluorescência , Óvulo Vegetal/anatomia & histologia , Óvulo Vegetal/metabolismo , Sementes/anatomia & histologia , Sementes/metabolismo
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