AGL9型E类基因ZmSEP3-a和ZmSEP3-b在玉米花器官发育过程中的功能研究

玉米花器官的形态特征和数目是影响其产量和品质的关键因素，开展玉米花器官发育机制的研究，对玉米分子育种具有重要意义。申请人采用反向遗传学的研究方法，鉴定到一对潜在参与玉米花器官发育的AGL9型E类的重复基因ZmSEP3-a和ZmSEP3-b。前期研究发现，ZmSEP3-a单基因突变会导致部分雄穗小花的花器官身份异常，小花中的雄蕊会转化为花丝状结构。表达分析发现ZmSEP3-a基因主要在玉米花序的各类分生组织中表达，如小穗分生组织和小花分生组织等。本项目将在此基础上，继续创制ZmSEP3-b基因的突变体，并与ZmSEP3-a构建双突变体进行深入的花器官形态学分析。同时，结合分子生物学和生物信息学等研究方法，对ZmSEP3-a和ZmSEP3-b基因功能进行系统性解析。该研究将揭示AGL9亚家族的E类基因在玉米花器官发育中的作用机制，完善玉米花发育调控网络，也为玉米品种的进一步改良提供理论支持。

The morphological characteristics and number of floral organs are the key factors affecting the yield and quality in maize. Studying on the mechanism of floral organ development is of great significance to maize molecular breeding. Through reverse genetics strategy, the applicant identified a pair of AGL9-like E class duplicated genes ZmSEP3-a and ZmSEP3-b that potentially involved in the development of maize floral organs. Previous studies have found that single gene mutation of ZmSEP3-a could lead to abnormal identity of floral organs in some of the tassel florets, in which the stamen would transform into silk-like structure. Expression analysis showed that ZmSEP3-a gene was mainly expressed in various types of meristem on maize inflorescence, such as spikelet meristem and floral meristem. Based on the previous research, this project will further create the ZmSEP3-b mutant, and construct double mutant with ZmSEP3-a for in-depth morphological analysis of floral organs. Furthermore, we will combine the research methods of molecular biology and bioinformatics to systematically analyze the functions of ZmSEP3-a and ZmSEP3-b genes. This study will reveal the regulatory mechanism of E class gene of AGL9 subfamily in maize floral organ development, improve the regulatory network of maize flower development, and provide theoretical support for further improvement of maize varieties.