黄瓜转录因子CsMADS-RIN调控脂氧合酶基因CsLOX09及CsLOX23参与醛类香气形成的分子机理

黄瓜果实清香味的浓淡取决于C9和C6醛的含量和比例。脂氧合酶基因CsLOX09及CsLOX23是决定C9及C6醛类含量的主效基因，但人们对调控它们的转录因子及机制知之甚少。通过对野生型和其醛类香气突变体发育果实的转录组数据分析表明，转录因子CsMADS-RIN在两者间差异显著且和C9醛类含量呈正相关，推测其在调控脂氧合酶基因表达中起重要作用。本项目拟通过酵母单杂交分析CsMADS-RIN对CsLOX09及CsLOX23的启动子活性，通过截短实验确定重要结构域并进行Chip-PCR验证；通过原生质体瞬时表达体系分析启动子重要结构域突变和在黄瓜自然材料中变异位点的作用；通过代谢组及Chip-seq分析CsMADS-RIN嵌合抑制子基因沉默、RNAi抑制表达及过表达分析对脂氧合酶途径和下游基因网络的影响，阐明CsMADS-RIN调控CsLOXs参与醛类形成的分子机制，为黄瓜风味品质改良奠定基础。

The content and ratio of C9 and C6 aldehydes denpends the deep or light odor of cucumber fruits. CsLOX09 and CsLOX23 are the major genes of aroma impact compounds of C9 and C6 aldehydes, which have the important effect on the flower-like odor, however, it was unknown to the transcription factors which involved in the synthesis of aldehydes and the molecular mechanism. The expression of transcription factor of CsMADS-RIN was significantly different between wild and it’s mutant of cucumber aroma and which had a positive correlation with the content of C9 aldehydes based on the analysis of the RNA-seq data of fruit during the development of the fruits from the mutant of M6347 and wild type No.26. It was assumed that CsMADS-RIN has an important regulation role on the synthesis of aldehydes. The promoter activity between CsMADS-RIN and CsLOXs will be analyzed using the method of yeast-one-hybrid, and the important motif of promoter was identified by truncating the promoter into different lengths and verified using Chip-PCR method.The chimeric repressor gene-silencing vector, RNAi vector and overexpression vector of CsMADS-RIN were constructed in order to study it’s effects to the lipoxygenase pathway and gene network of downstream, which will helpful to understand the molecular mechanism of cucumber transcription factor CsMADS-RIN participating in the regulation of CsLOX09 and CsLOX23 on the synthesis of fruit aldehydes, and which will put some basis for the improvement of cucumber flavor quality in the future.