钙离子结合蛋白基因BnA09.BA1调控油菜分枝角度的功能分析

分枝角度是影响油菜机械化收获效率的重要株型性状。本项目前期通过关联分析在A09染色体检测到一个新的分枝角度主效位点qBA.A9.2，区间长210 kb；通过基因共表达网络分析、候选基因关联分析和eQTL分析在该区间确定一个候选基因，命名为BnA09.BA1。BnA09.BA1编码一个钙离子结合蛋白，大分枝角度株系中第六外显子上一个4 bp缺失导致基因发生移码突变，翻译提前终止，蛋白缺失整个结合钙离子的EF-hand结构域和部分具有催化活性的EEP结合域。目前尚未见BnA09.BA1及其同源基因调控分枝角度的报道。在此基础上，本项目通过转基因验证BnA09.BA1并开发功能标记；对野生型和转基因植株的分枝进行生理学和细胞学分析；分析BnA09.BA1的时空表达模式、亚细胞定位及下游生长素途径基因的表达，解析BnA09.BA1调控分枝角度的生物学机制，为培育紧凑株型油菜提供基因资源。

Branch angle of rapeseed is a crucial plant-type trait conducive to mechanized harvesting. In our previous study, we detected one branch angle major locus qBA.A9.2 on chromosome A09 with a confidence interval of 210 kb by genome-wide association study (GWAS). By a combination of weighted correlation network analysis (WGCNA), candidate gene association study and eQTL analysis, we narrowed the candidate list down to one gene (BnA09.BA1), which encodes a calcium binding protein. For large branch angle accessions, one deletion of 4 bp within the 6th exon of their allele BnA09.ba1 resulted in a frameshift mutation, which caused a premature termination of translation, so BnA09.ba1 lost part of the catalytic EEP domain and the whole Ca2+-binding EF-hand domain. Based on the previous results, we plan to perform the genetic complementation test and develop a functional marker, followed by cytological and physiological observation, subcellular localization assays, as well as BnA09.BA1 and downstream auxin pathway genes expression analysis. This project will contribute to a better understanding of the genetic control of branch angle in rapeseed, and provide a valuable gene for breeding of new varieties with compact plant architecture.