III型AtOFPs转录因子对拟南芥荚果形态的调控

项目名称： III型AtOFPs转录因子对拟南芥荚果形态的调控

项目编号： No.31470297

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 王树才

作者单位： 东北师范大学

项目金额： 90万元

中文摘要： 拟南芥卵形蛋白家族（AtOFPs）是申请者发现的一个新型的转录抑制因子家族，可以调控植物多种器官的形态，但其作用机理尚不清楚。基于转基因植株表型差异，我们将AtOFPs分为3种类型，其中III型 AtOFPs过表达植株具有平末端荚果，与类受体蛋白激酶基因突变体er表型类似，且可被过表达ER所恢复，而ER已被证明可通过促分裂原活化蛋白激酶（MAPK）级联途径调控植物的生长发育。在此基础上，本项目拟综合利用分子生物学、遗传学、生物信息学等学科的技术和方法，以III型AtOFPs转录因子AtOFP15和16为主，从分析其与ER在调控荚果形态中的关系，鉴定其靶基因，探究MAPK级联途径是否参与调控其蛋白磷酸化等三个方面解析III型AtOFPs转录因子调控拟南芥荚果形态的机理。研究结果将丰富AtOFPs调控植物组织器官形态的作用机制的理论知识，为利用卵形蛋白家族基因进行农作物的性状改良提供理论依据。

中文关键词： 转录因子；卵形蛋白；荚果形态；基因表达调控；拟南芥

英文摘要： In Arabidopsis, there are 18 genes encoding Arabidopsis thaliana Ovate Family Proteins (AtOFPs). A couple of years ago, we identified AtOFPs as a novel transcription repressor family and found that AtOFPs regulate multiple aspects of plant growth and development including tissue and organ morphogenesis, however, the mechanisms underlining the functions of AtOFPs remain largely unknown. All the AtOFPs mutants identified so far including Atofp1, Atofp4, Atofp8, Atofp10, Atofp15 and Atofp16 single mutants, and Atofp1 Atofp4 and Atofp15 Atofp16 double mutants are morphologically similar to wild type plants, however, plants overexpressing AtOFPs displayed a number of abnormal phenotypes, which could be categorized into three distinct classes, indicating that AtOFPs have overlapping and diverse functions in regulating plant growth and development. Accordingly, AtOFPs were categorized into three classes, Class I, II and III AtOFPs. Plants overexpressing any of the four Class III AtOFPs genes including AtOFP13, AtOFP15, AtOFP16 and AtOFP18 have blunt-ended siliques, a phenotype that was also observed in er, a mutant of the receptor like protein kinase gene ERECTA (ER), and overexpression of ER in AtOFP15 or AtOFP16 overexpressing plants restored their blunt-ended siliques phenotypes. These results suggest that Class III AtOFPs and ER may work in the same signaling pathway in regulating silique morphology. ER has been shown to regulate plant growth and development through mitogen-activated protein kinase (MAPK) cascades, the universal signal transduction modules in eukaryotes including plants. MAPK cascades mediate intracellular transmission and amplification of extracellular stimuli through sequential protein phosphorylation, and both AOFP15 and AtOFP16 have predicated MAPK phosphorylation sites, so it is like MAPK cascades mediated protein phosphorylation also involved in Class III AtOFPs regulated silique morphology. In this proposal, a combination of plant molecular biology, genetics, biochemistry and bioinformatics approaches going to be use to study the mechanisms underneath the regulation of silique morphology by Class III AtOFPs transcription factor AtOFP15 and AtOFP16. Proposed studies include but may not limited to dissection of the relationship between Class III AtOFPs and ER, identification of target genes of Class III AtOFPs transcription factors, examination of the protein phosphorylation of Class III AtOFPs and test of the potential effects of protein phosphorylation on the transctiptional activities of Class III AtOFPs. Results gain from the proposed studies will enhance our knowledge of the regulation of plant tissue and organ morphogenesis by AtOFPs, and may lead to the improvement of crop quality by modification of AtOFP genes.

英文关键词： Transcription factor;Ovate proteins;Silique morphology;Gene expression;Arabidopsis