玉米株高控制基因DWARF AND STIFF 的克隆与功能研究

株高对提高农作物收获指数及抗倒伏能力等方面具有十分重要的作用，绿色革命中小麦和水稻的半矮化育种极大推动了农业生产。大多数玉米矮化材料都伴随性别决定或产量等方面的不利影响，导致生产上的玉米品种普遍植株高大。本项目分离到一份玉米自发的矮生突变体dwarf and stiff (das)，该突变体节间数和节间长度均明显下降，但性别决定和育性并无异常，激素处理显示该突变体与赤霉素合成和信号通路无关。精细定位区间含有两个候选基因，均非已知玉米株高相关基因。目前正在进行编辑，以明确引起表型的基因。我们将通过不同植物激素报告株系对DAS基因参与的信号通路进行研究；利用转录组测序推断受该基因调控的下游基因；借助酵母双杂交和IP-MS技术鉴定互作蛋白；通过转基因和双突变体研究揭示与DAS的遗传学关系，解析控制玉米株高的新机制和分子网络，为玉米矮化株型分子设计育种提供基因原件和理论支持。

Plant height is important for harvest index and lodging resistance of corps. The application of semi-dwarf cultivars in Green Revolution had greatly promoted the production of wheat and rice. However, the mechanisms controlling the plant height of maize are not identical with that of wheat and rice. Due to the fact that most maize dwarf germplasms identified so far couple with disturbance including sex determination and yield, the popular maize cultivars are tall. In this project, we isolated a spontaneous maize dwarf mutant, stiff and dwarf (das)，which has no defects in sex determination and fertility. Treatment with hormones indicated that the mutant may not be involved in gibberellin pathway. Two candidate genes were identified by map-based cloning, and none of them had been reported to be related with plant height. Gene editing on these two candidates are underway to confirm the causative gene. Next, the gene function will be verified by allelism tests, transgenic complementation, and gene editing experiments; RNA expression and protein sub-cellular localization patterns will be also revealed; Whether and how DAS participate plant hormone pathways will be investigated by introducing various plant hormone reporters and comparing their expression patterns between the wild type das plant; The downstream genes regulated by DAS will be identified by transcriptome sequencing; and DAS interacting proteins will be revealed by yeast two hybrid screen and IP-MS; We expect that a novel molecular mechanism and the regulatory network controlling the plant height of maize could be revealed by the efforts of this project.