两个黄瓜无毛突变体基因互作的遗传解析及分子机理研究

It lacks thorough research of molecular mechanism about gene interactions in cucumber because of no proper experimental materials and necessary genome sequence. Trichome is an important trait for plant. It involves many resistance metabolisms to diseases and stress in plant. Cucumber with no trichomes can resist to some insects and reduce pesticide residus.We preserve two cucumber glabrous mutants named 1945 and NCG-042. In this project, based on the primary conclusion of gene interactions between the genes of gl and gl-2 controlling development of trichome in cucumber, the functions of gl and gl-2 for trichome development will be studied. Fine mapping and gene cloning of the gl-2 gene will be conducted making full use of the whole genome sequence and re-sequencing of NCG-042. Functional analysis will be done for the gl-2 candidate genes through trans-gene technology. Using the information of gl candidate gene provided by our cooperation partner, interaction relations between gl and gl-2 gene will be made clear by sequence comparison, gene homology and expression analysis, and Yeast two-hybrid experiments. So, the hypothesis of "the compound of different gene products controlling the development of cucumber trichomes" will be made verified in the molecular level. This study aimed at mining the key genes controlling the development of cucumber trichomes and revealing the interactions between these genes. The results of the present study have significant impact on clarifying molecular mechanism of trichome development and regulation in cucumber, and it can provide academic guidance and practical molecular markers to the glabrous and insect resistance breeding program.

由于缺乏合适的试验材料和必要的基因组信息，对于黄瓜基因互作的分子机制缺乏深入研究。表皮毛是植物的重要性状，参与部分抗病抗逆过程，无毛黄瓜具有抗虫、减少农残等特点。本项目以发现两个黄瓜无毛突变体1945和NCG-042通过基因互作控制表皮毛发育这一科学问题为切入点，开展gl和gl-2基因在表皮毛发育过程中的功能研究。项目将充分利用全基因组测序及重测序信息，快速实现gl-2基因的精细定位及克隆，进行功能验证；利用合作者提供的gl候选基因，通过序列比较、同源性分析、转基因表达分析和酵母双杂交实验，对gl和gl-2的互作关系进行解析，从分子水平验证"不同基因产物组成的复合物控制黄瓜表皮毛发育"的假设。本研究拟通过高效率的技术路线挖掘黄瓜表皮毛形成的关键基因并揭示其互作关系，对于明确表皮毛发育的内在分子机制具有重要意义，同时可为创新无毛的抗虫黄瓜种质提供理论依据。

本研究以三个黄瓜无毛突变体gl1、gl2和gl3通过基因互作控制表皮毛发育这一科学问题为切入点，开展csgl1/csgl2/csgl3基因在表皮毛发育过程中的功能研究。完成了无毛基因csgl2和csgl3的精细定位、克隆及功能验证。其中黄瓜无毛基因csgl2定位在2号染色体上，与细胞分裂素生物合成、分生组织结构等生物进程具有一定的相关性。黄瓜无毛基因csgl3定位在6号染色体上，属于HD-Zip蛋白家族，与表皮细胞分化相关；遗传分析发现三个无毛突变基因csgl1、csgl2和csgl3两两之间存在基因互补作用；利用酵母双杂交系统发现csgl3基因的两个结构域START_ArGLABRA2_like 和 DNA binding分别与csgl1和csgl2基因发生蛋白互作，由此从分子水平说明三个黄瓜无毛基因csgl1/csgl2/ csgl3彼此之间确实存在互作。本研究对于明确表皮毛发育的内在分子机制具有重要意义，同时可为创新无毛抗虫黄瓜种质提供理论依据。