茶树MYB7转录因子功能的研究

Study on the function of MYB7 transcription factor from Camellia sinensis

MYB转录因子是一类类黄酮代谢途径的重要调控因子,但是茶树中相关研究依然很少。克隆1条第7亚族R2R3-MYB基因,其开放阅读框为994 bp,编码328个氨基酸。荧光定量分析表明,Cs MYB7-1在茶树各个组织中均有表达,其中在花中表达最高而在根中表达最低;Cs MYB7-1的表达受到甘露醇处理的诱导。过表达Cs MYB7-1的烟草花色和花的形态并没有表现出特殊的症状,但是LC-3Q/MS分析表明过表达Cs MYB7-1基因的烟草花中咖啡奎宁酸和芸香苷含量升高,而山奈酚-3-O-芸香苷的含量降低;荧光定量分析表明,转基因烟草中类黄酮代谢途径中的一些关键基因相对表达发生了变化。

MYB transcription factor is one of the important regulatory factors involved in the flavonoid bio- synthesis pathway; however, the function of MYBs in tea （Camellia sinensis） is less studied. In this study, we screened one MYB gene in tea genome, CsMYB7-1, which belongs to subgroup 7. We took tea leaves as material and obtained a full-length sequence. The open reading frame was 994 bp in length and encoded a protein of 328 amino acids. Real-time quantitative PCR analysis revealed that CsMYB7-1 expressed in all tissues of tea and the relative expression level of CsMYB7-1 was the highest in petals and the least in root tissues. The expression of CsMYB7-1 in tea seedlings was significantly upregulated after treated with 90 mmol/L mannitol. There was no significant difference in flower color and flower morphology of transgenic tobaccos after over-expression of CsMYB7-1, but LC-3Q/MS analysis of MYB7 over-expression tobacco flowers showed that the caffeoylquinic acid content and rutin content increased, while the kaempferol 3-O-glucosylrutinoside content decreased com- pared with the wild type. Real-time quantitative PCR analysis showed that the expression of several genes involved in the flavonoid synthetic pathway enhanced.