RESUMO
MAIN CONCLUSION: TaAGL66, a MADS-box transcription factor highly expressed in fertile anthers of KTM3315A, regulates anther and/or pollen development, as well as male fertility in wheat with Aegilops kotschyi cytoplasm. Male sterility, as a string of sophisticated biological processes in higher plants, is commonly regulated by transcription factors (TFs). Among them, MADS-box TFs are mainly participated in the processes of floral organ formation and pollen development, which are tightly related to male sterility, but they have been little studied in the reproductive development in wheat. In our study, TaAGL66, a gene that was specifically expressed in spikes and highly expressed in fertile anthers, was identified by RNA sequencing and the expression profiles data of these genes, and qRT-PCR analyses, which was localized to the nucleus. Silencing of TaAGL66 under fertility condition in KTM3315A, a thermo-sensitive male sterile line with Ae. kotschyi cytoplasm, displayed severe fertility reduction, abnormal anther dehiscence, defective pollen development, decreased viability, and low seed-setting. It can be concluded that TaAGL66 plays an important role in wheat pollen development in the presence of Ae. kotschyi cytoplasm, providing new insights into the utilization of male sterility.
Assuntos
Aegilops , Citoplasma , Fertilidade , Regulação da Expressão Gênica de Plantas , Infertilidade das Plantas , Proteínas de Plantas , Pólen , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Triticum/fisiologia , Citoplasma/metabolismo , Citoplasma/genética , Pólen/genética , Pólen/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Aegilops/genética , Infertilidade das Plantas/genética , Fertilidade/genética , Flores/genética , Flores/crescimento & desenvolvimento , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Genes de Plantas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
MAIN CONCLUSION: The loss of TaMYB305 function down-regulated the expression of jasmonic acid synthesis pathway genes, which may disturb the jasmonic acid synthesis, resulting in abnormal pollen development and reduced fertility. The MYB family, as one of the largest transcription factor families found in plants, regulates plant development, especially the development of anthers. Therefore, it is important to identify potential MYB transcription factors associated with pollen development and to study its role in pollen development. Here, the transcripts of an R2R3 MYB gene TaMYB305 from KTM3315A, a thermo-sensitive cytoplasmic male-sterility line with Aegilops kotschyi cytoplasm (K-TCMS) wheat, was isolated. Quantitative real-time PCR (qRT-PCR) and promoter activity analysis revealed that TaMYB305 was primarily expressed in anthers. The TaMYB305 protein was localized in the nucleus, as determined by subcellular localization analysis. Our data demonstrated that silencing of TaMYB305 was related to abnormal development of stamen, including anther indehiscence and pollen abortion in KAM3315A plants. In addition, TaMYB305-silenced plants exhibited alterations in the transcriptional levels of genes involved in the synthesis of jasmonic acid (JA), indicating that TaMYB305 may regulate the expression of genes related to JA synthesis and play an important role during anther and pollen development of KTM3315A. These results provide novel insight into the function and molecular mechanism of R2R3-MYB genes in pollen development.
Assuntos
Aegilops , Infertilidade , Oxilipinas , Ciclopentanos , Citoplasma/genética , Genes myb , Pólen/genética , TriticumRESUMO
MAIN CONCLUSION: The loss of TaGAMYB function in Arabidopsis results in abnormal pollen development and leads to decreased fertility. This process may be regulated by microRNAs, which suppress the expression of fatty acid pathway genes. Development of the anthers and pollen is significantly influenced by the transcription factor GAMYB. However, our knowledge of GAMYB in wheat is limited. Here, under fertility and sterility conditions, we identified the distinct transcripts TaGAMYB-d and TaGAMYB-g in thermosensitive genic sterile wheat YanZhan 4110S and confirmed their functions. TaGAMYB-g overexpression decreased the pollen vigor and germination rates, thereby reducing fertility. TaGAMYB-d overexpression lines exhibited early flowering. Due to aberrant pollen germination, the mutant homologous TaGAMYB genes in Arabidopsis thaliana also resulted in lower fertility. Our findings indicate that TaGAMYB controls the fertility and flowering time in transgenic Arabidopsis thaliana.
