一个新的玉米显性花器官发育缺陷基因克隆与功能分析

花器官发育是影响玉米产量及品质的重要因子。目前，对玉米花发育分子机制的研究仍较为薄弱。本课题组在玉米突变体库中筛选到一份花器官发育缺陷的显性突变体Silky3。该突变表型由一个单基因控制，且突变表型与突变基因的拷贝数相关，表现为剂量效应。Silky3突变体影响玉米早期的雌雄穗发育，主要表现为玉米雌雄花序各级分生组织的发育异常，以及雌雄穗小花的性别决定过程紊乱，最终导致额外小花的形成及雄穗顶端结实等异常表型。我们利用图位克隆的策略获得了候选基因，发现SILKY3是一个全新的花发育相关基因。由于转座子插入，该基因在突变体发育早期的雌雄穗中异位表达，特别是小穗分生组织顶端特异表达。本项目拟在前期的研究基础上，通过转基因、基因组学、蛋白组学等研究方法探索该基因在玉米花器官发育中的功能。研究将进一步丰富玉米花器官发育的分子调控机制，也可以为玉米品种改良提供理论支撑。

Flora organ development is an important factor affecting corn yield and quality. Currently, the research on the development of flower in maize is still limited. Our group obtained a dominant mutant, named Silky3, with defects in the flora organ development by screening the maize mutant library. A single gene controls the mutation phenotype, and its phenotype is in correlation to the copy number of the mutant gene, showing a dosage effect. The Silky3 mutation affects the early development of the male and female flower in maize. The mutant exhibits abnormal development of the meristems in male and female inflorescences, and disorder of the sex determination in tassel spikelet, which leads to the formation of extra florets and tassel-seed. We isolated the candidate gene by map-based cloning, and found that the SILKY3 is a novel flower development-related gene. A transposon insertion caused the ectopic expression of SILKY3 in young ear and tassel, especially in the spikelet meristem. Based on the previous research, this project will continue to explore the role of SILKY3 in the maize flower development through multiple research methods, such as transgenic, genomics and proteomics. This research will further improve our understanding of the molecular regulation mechanism of maize flora organ development, and provide theoretical support for the improvement of maize varieties.