SlMAX2a/b在侧枝发育中的分子机制及SLs在番茄栽培中的应用研究

独脚金内酯（Strigolactones，SLs ）调控植物侧枝发育的分子机制尚未明确，在番茄分枝发育中的研究较少。本项目重点研究SlMAX2a和SlMAX2b基因在调控番茄侧枝发育中的生物学功能。拟通过利用基于tRNA加工系统的增强型CRISPR/Cas9基因编辑技术获得SlMAX2a/b的单突变体，同时利用VIGS技术获得SlMAX2a/b基因的双突变体。以突变体及超表达株系为材料，通过表型、组织特异性、亚细胞定位、内源独脚金内酯和生长素含量分析，以及利用酵母单、双杂文库筛选，凝胶阻滞分和免疫共沉淀验证，探索SlMAX2a和SlMAX2b调控番茄侧枝长发育的机制及独脚金内酯与生长素信号通路的关系。通过建立高效液相色谱串联质谱法测定SLs的种类和结构，并深入研究外源SLs处理对番茄生长发育的影响。本研究可为SLs调控番茄侧枝发育提供遗传学和分子生物学依据，为番茄栽培管理提供理论基础。

The molecular mechanism of strigolactones in regulation of plant lateral branch development remains unclear, and the research on tomato branch development is less. This project focuses on the biological function of SlMAX2a and SlMAX2b, the homologous gene of AtMAX2, in the regulation of collateral development in tomato. SlMAX2a and SlMAX2b are highly conserved genes. We are going to obtain the single mutant of SlMAX2a or SlMAX2b by using the boosting CRISPR/Cas9 multiplex editing capability with the endogenous tRNA-processing system, and the double mutants of SlMAX2a and SlMAX2b using VIGS technology. In this project, we will investige the function of SlMAX2a and SlMAX2b genes in regulation of collateral development using mutants and overexpression lines, and explore the relationship between strigolactones and auxin signaling pathway. The phenotype of the mutants and wild type, temporal and spiral location and subcellular localization of SlMAX2a and SlMAX2b will be carried out. Analysis of endogenous strigolactones and auxin content, the yeast single and two hybrid library screening, gel retardation assay and immune co-precipitation, will be used in this research. We will establish a HPLC-MS/MS method for the determination of the structure and the contents of the SL, and study the effect of GR24 treatment on the growth of the tomato. The project provides genetics and molecular biology basis for strigolactones regulating lateral branch development in tomato, and also provides a theoretical basis for the tomato cultivation and management.