玉米矮杆基因及其调控网络的发掘

Plant height is one of the important breeding properties of maize, which is closely related to crop yield, economic coefficient, photosynthetic characteristics, and lodging resistance. Though a few genes which regulate maize plant height were cloned, the molecular mechanism under it was not elucidated yet due to the complicated genetic mechanism. We obtained a series of maize mutants with the phenotype of dwarf, lower ear position and wide leaves by insertion of Mu transposons. The mutants were grown in two different sites and the offspring inherited those properties stably, which is in agreement with the law of segregation ratio of a single gene. In this research, the stem cells within shoot apical meristem will be isolated by using the technique of laser capture microdissection. The genes regulating plant height in these cells will be analyzed by RNA-seq technique; Illumina sequence analysis was combined with genetic linkage for fine mapping and cloning genes and their biological functions will be completely clarified through a variety of techniques covering biochemistry, molecular and cellular biology, and genetics. Nested Association Mapping (NAM) Population was used for Mutant-Assisted Gene Identification and Characterization (MAGIC) to look for the enhancers and repressors of these genes. At the same time, the genes which involved in the regulation of plant height will be discovered through transcriptomics analysis, and the gene regulation network of plant height will be elucidated. Taken together, all of these cloned genes and important QTL will be the milestone and provide important markers for pyramid breeding.

玉米的株高与产量、经济系数、光合特征和抗倒伏性等重要农艺性状密切相关，是决定株型的关键性状。由于形成玉米株高的遗传学机理十分复杂，到目前为止仅少数几个调控玉米株高的基因被克隆，且其分子调控机理尚未被清晰阐述。本实验室通过Mu转座插入获得了一系列植株矮化、穗位超低、叶片宽大的突变体。两地点种植表明其性状稳定，符合单基因分离比例。本研究拟利用激光捕获显微切割急速分离突变体和正常玉米顶端分生组织单细胞，利用RNA-seq技术分析控制株高的相关基因，初步解析出控制株高的调控网络；采用Illumina测序结合遗传连锁分析的方法进行定位并克隆基因；同时利用生物化学、细胞生物学及遗传学方法阐明其生物学功能；利用现有的巢式关联作图（NAM）群体进行突变体辅助基因定位和表征分析（MAGIC），查找控制该基因的增强子和抑制子；所获得的关键基因和重要QTL将为聚合育种提供理论支撑和分子标记。

玉米的株高和穗位高与产量、经济系数、光合特征和抗倒伏性等重要农艺性状密切相关，是决定株型的关键性状。本研究以株高和穗位超低的突变体为研究对象，与B73构建F2、F3及回交群体，定位到控制株高、穗位高的候选基因ZmTLP。目前正在鉴定转基因植株的性状。对回交材料和对照材料B73进行转录组学测定，发现玉米中维管束形成相关的基表达量发生显著变化。