Project description:In flowering plants, anther dehiscence and pollen release are essential for sexual reproduction. Anthers dehisce after cell wall degradation weakens stomium cell junctions in each anther locule, and desiccation creates mechanical forces that open the locules. Either effect or both together may break stomium cell junctions. The microRNA miR167 negatively regulates ARF6 and ARF8, which encode Auxin Response transcription Factors. Arabidopsis mARF6 or mARF8 plants with mutated miR167 target sites have defective anther dehiscence and ovule development. Null mir167a mutations recapitulated mARF6 and mARF8 anther and ovule phenotypes, indicating that MIR167a is the main miR167 precursor gene that delimits ARF6 and ARF8 expression in these organs. Anthers of mir167a or mARF6/8 plants overexpressed genes encoding cell wall loosening functions associated with cell expansion, and grew too large starting at flower stage 11. Experimental desiccation enabled dehiscence of miR167-deficient anthers, indicating competence to dehisce. Conversely, high humidity conditions delayed anther dehiscence in wild-type flowers. These results support a model in which miR167-mediated anther growth arrest permits anther dehiscence. Without miR167 regulation, excess anther growth delays dehiscence by prolonging desiccation.
Project description:The coordination of pollen viability, stamen filament elongation and anther dehiscence is essential for the successful pollination and reproduction in angiosperms. The hormone jasmonic acid (JA) are crucial for these processes. However, the tight regulation of JA biosynthesis during stamen development is still largely unknown. Here, we demonstrate that the rice (Oryza sativa) ERF-associated amphiphilic repression (EAR) motif-containing protein TCP INTERACTOR CONTAINING EAR MOTIF PROTEIN1 (OsTIE1) tightly regulates JA biosynthesis by repressing TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATINGCELLFACTORS (TCP) transcription factor OsTCP1/PCF5 during stamen development. The loss of OsTIE1 function in ostie1 mutants causes male sterility. The ostie1 mutants display inviable pollen, the early stamen filament elongation and the precocious anther dehiscence. JA biosynthesis is activated earlier and JA level is precociously increased in anthers of ostie1. The expression of OsTIE1 is developmentally regulated during stamen development. OsTIE1 is localized in nuclei and has transcriptional repression activity. We further show that OsTIE1 directly interacts with OsTCP1, and overexpression of OsTCP1 caused early anther dehiscence resembling that of ostie1. The expression of genes encoding key enzymes of JA biosynthesis including Oryza sativa lipoxygenase (OsLOX) genes is regulated by the OsTIE1-OsTCP1 complex. Our findings discover that the OsTIE1-OsTCP1 module plays critical roles in stamen development by finely tuning JA biosynthesis, and provides a new foundation to create male sterile plants for hybrid seed production.
Project description:We identified and characterized that the rice Dioxygenase for Auxin Oxidation (dao) mutant displays pleiotropic phenotypes, including indehiscent anthers, sterile pollens, and increased free IAA levels in anthers.We conclude that DAO-mediated auxin catabolism is essential for auxin homeostasis and later stages of plant reproductive development, including anther dehiscence, and pollen viability. We used microarrays to identify differentially expressed genes in dao.
Project description:Anther development is a complex process, and the study of its molecular mechanism has an important impact on plant breeding. This study aims to identify microRNA (miRNA), mRNA, long non-coding RNA (lncRNA), and circular RNA (circRNA) related to anther development of Chinese cabbage, so as to construct competitive endogenous RNA (ceRNA) regulatory networks and provide valuable knowledge for the exploration of pollen development mechanism of Chinese cabbage. A total of 9055 mRNA, 585 miRNA, 1344 lncRNA, and 165 circRNA were identified as differentially expressed in the anther of Chinese cabbage compared with Mix (roots, stems and leaves) by whole-transcriptome sequencing. The anther-related ceRNA-miRNA-target gene regulatory network through miRNA targeting relationships was constructed and 450 pairs of ceRNA relationships, including 97 DEmiRNA-DEmRNA, 281 DEmiRNA-DElncRNA, and 23 DEmiRNA-DEcircRNA interactions were obtained in Chinese cabbage. The genes in the ceRNA network were enriched in the pathways including starch and sucrose metabolism, carbon metabolism, pyruvate metabolism and carbon fixation in photosynthetic organisms, plant hormone signal transduction, and RNA degradation. This study identified some important genes and their interaction lncRNAs, circRNAs, and miRNAs involved in microsporogenesis (BraA06g035480.3C), tapetum and callose layer development (BraA09g009280.3C, BraA04g028920.3C, and BraA10g022680.3C etc), pollen wall formation (BraA06g000980.3C, BraA02g023130.3C, and BraA10g029650.3C etc), and anther dehiscence (BraA10g027200.3C, BraA04g023740.3C, and BraA04g030860.3C etc). Additionally, we analyzed the promoter activity of six anther predominant expression genes, and the results showed that they were all expressed specifically in the anther of Chinese cabbage. This study lay the foundation for further research on the molecular mechanism of anther growth and development.
Project description:Anther development is a complex process, and the study of its molecular mechanism has an important impact on plant breeding. This study aims to identify microRNA (miRNA), mRNA, long non-coding RNA (lncRNA), and circular RNA (circRNA) related to anther development of Chinese cabbage, so as to construct competitive endogenous RNA (ceRNA) regulatory networks and provide valuable knowledge for the exploration of pollen development mechanism of Chinese cabbage. A total of 9055 mRNA, 585 miRNA, 1344 lncRNA, and 165 circRNA were identified as differentially expressed in the anther of Chinese cabbage compared with Mix (roots, stems and leaves) by whole-transcriptome sequencing. The anther-related ceRNA-miRNA-target gene regulatory network through miRNA targeting relationships was constructed and 450 pairs of ceRNA relationships, including 97 DEmiRNA-DEmRNA, 281 DEmiRNA-DElncRNA, and 23 DEmiRNA-DEcircRNA interactions were obtained in Chinese cabbage. The genes in the ceRNA network were enriched in the pathways including starch and sucrose metabolism, carbon metabolism, pyruvate metabolism and carbon fixation in photosynthetic organisms, plant hormone signal transduction, and RNA degradation. This study identified some important genes and their interaction lncRNAs, circRNAs, and miRNAs involved in microsporogenesis (BraA06g035480.3C), tapetum and callose layer development (BraA09g009280.3C, BraA04g028920.3C, and BraA10g022680.3C etc), pollen wall formation (BraA06g000980.3C, BraA02g023130.3C, and BraA10g029650.3C etc), and anther dehiscence (BraA10g027200.3C, BraA04g023740.3C, and BraA04g030860.3C etc). Additionally, we analyzed the promoter activity of six anther predominant expression genes, and the results showed that they were all expressed specifically in the anther of Chinese cabbage. This study lay the foundation for further research on the molecular mechanism of anther growth and development.
Project description:In plants, secondary wall thickenings play important roles in various biological processes, although the factors regulating these processes remain to be characterized. We show that expression of chimeric repressors derived from NAC SECONDARY WALL THICKENINGS PROMOTING FACTOR1 (NST1) and NST2 in Arabidopsis resulted in an anther dehiscence defect due to loss of secondary wall thickening in anther endothecium. Plants with double, but not single, T-DNA-tagged lines for NST1 and NST2, had the same anther-indehiscent phenotype as transgenic plants that expressed the individual chimeric repressors, indicating that NST1 and NST2 are redundant in regulating secondary wall thickening in anther walls. The activity of the NST2 promoter was particularly strong in anther tissue, while that of the NST1 promoter was detected in various tissues in which lignified secondary walls develop. Ectopic expression of NST1 or NST2 induced ectopic thickening of secondary walls in various above-ground tissues. Epidermal cells with ectopic thickening of secondary walls had structural features similar to those of tracheary elements. However, among genes involved in the differentiation of tracheary elements, only those related to secondary wall synthesis were clearly upregulated. None of the genes involved in programmed cell death was similarly affected. Our results suggest NAC transcription factors as possible regulators of secondary wall thickening in various tissues. Keywords: transgenic vs wt comparison
Project description:In plants, secondary wall thickenings play important roles in various biological processes, although the factors regulating these processes remain to be characterized. We show that expression of chimeric repressors derived from NAC SECONDARY WALL THICKENINGS PROMOTING FACTOR1 (NST1) and NST2 in Arabidopsis resulted in an anther dehiscence defect due to loss of secondary wall thickening in anther endothecium. Plants with double, but not single, T-DNA-tagged lines for NST1 and NST2, had the same anther-indehiscent phenotype as transgenic plants that expressed the individual chimeric repressors, indicating that NST1 and NST2 are redundant in regulating secondary wall thickening in anther walls. The activity of the NST2 promoter was particularly strong in anther tissue, while that of the NST1 promoter was detected in various tissues in which lignified secondary walls develop. Ectopic expression of NST1 or NST2 induced ectopic thickening of secondary walls in various above-ground tissues. Epidermal cells with ectopic thickening of secondary walls had structural features similar to those of tracheary elements. However, among genes involved in the differentiation of tracheary elements, only those related to secondary wall synthesis were clearly upregulated. None of the genes involved in programmed cell death was similarly affected. Our results suggest NAC transcription factors as possible regulators of secondary wall thickening in various tissues. Experiment Overall Design: Total RNA was extracted from rosette leaves of two independent 2-week-old T1 plants over-expressing NST1 driven by 35S promoter and the whole transcriptome was compared with that of wild-type plant.
Project description:Pod dehiscence is an important agronomic trait. Pod dehiscence would cause huge yield losses before soybean maturity. Although some of soybean pod dehiscence associated genes have been identified, the underlying mechanism of pod dehiscence is still not comprehensively explained. In this study, we have identified differentially expressed genes (DEGs) between shattering-resistant and shattering-susceptible soybean accessions based on transcriptome analyses of 10 soybean accessions. Long non-coding RNAs (lncRNAs) that may be involved in soybean pod dehiscence were also identified, and we constructed co-expression networks between mRNAs and lncRNAs. RNA sequencing results were further verified by real-time PCR. Furthermore, DEGs were screened through analyzing positions of soybean pod dehiscence quantitative trait locus (QTLs) and phenotypes of soybean pod dehiscence for achieving pod-dehiscence candidate genes.