黄瓜果刺基座大小基因CsSBS的功能分析与调控机制研究

The size of fruit spines is one of the important indicators for evaluating the commodity quality of cucumber fruits. Usually, the spine is composed of a stalk and a base, and the size of the spine is determined by the multi-cellular base. Therefore, the size of the spine base is of great significance for the commodity quality of cucumber fruits. However, the mechanisms of molecular regulation in the formation of spine base are still unclear. Previously, one pair of mutants on spine base size from near isogenic lines was created by the group, and we isolated the Spine Base Size gene (CsSBS) by map-based cloning. Therefore, in this project we focus our study on the CsSBS, we will analyze its temporal and spatial expression patterns, and explore its expression patterns in cucumber lines with different spine base. Further, we will generate the CsSBS overexpression, RNAi and CRISPR-CAS9 constructs and introduce them into cucumber plants, analyze the biological function of CsSBS through phenotype characterization in the transgenic plants. Besides, yeast two-hybrid screening assay, BIFC and yeast two-hybrid assays will be used to screen the interacting proteins of CsSBS, and to elucidate its molecular mechanisms. We hope the expected results will be useful to reveal more about the molecular mechanisms of cucumber fruit spine base development, and to enrich the theory of plant epidermal differentiation. In addition, a better understanding of fruit spine base development might contribute to molecular marker-assisted breeding in cucumber.

果刺大小是评价黄瓜果实商品品质的重要指标之一，其由上部杆状刺和下部球状基座组成，而下部多细胞球状基座决定果刺大小。因此，果刺基座大小对黄瓜商品品质具有重要意义。但迄今，有关黄瓜果刺基座大小的分子机制及其调控途径尚不清楚。课题组前期构建了1对果刺基座大小不同的近等基因系，并以此为材料，通过图位克隆的方法分离到黄瓜果刺基座大小基因CsSBS。本研究拟在此基础上，首先，分析CsSBS基因的时空表达模式，并检测其在不同果刺大小的黄瓜材料中的表达差异；其次，构建过表达、干扰表达和CRISPR-CAS9基因编辑载体，对黄瓜进行遗传转化，通过表型观察和分析探讨CsSBS基因的生物学功能；再次，通过酵母文库筛选和酵母双杂与双分子荧光互补验证，明确CsSBS的互作蛋白，阐明其调控路径。预期结果将有助于揭示黄瓜果刺基座形成的分子机制，丰富植物表皮分化理论，同时为以果刺为目标性状的黄瓜分子育种提供理论基础。

果刺大小是评价黄瓜果实商品品质的重要指标之一，其由上部杆状刺和下部球状基座组成，而下部多细胞球状基座决定果刺大小。因此，果刺基座大小对黄瓜商品品质具有重要意义。但迄今，有关黄瓜果刺基座大小的分子机制及其调控途径尚不清楚。在本项目中，我们构建了1对果刺基座大小不同的近等基因系，并以此为材料，通过图位克隆的方法分离到黄瓜果刺基座大小基因CsSBS1。对果刺基座大小基因CsSBS1进行了表达模式分析、功能验证和分子机制解析，最终获得一个相对完善的调控黄瓜果刺基座发育的分子模式，对于以果实光滑度为育种目标的黄瓜品质育种具有重要的理论指导意义。