利用基因芯片筛选茶树芽叶紫化相关基因

Young Shoot Purple-Related Gene Screening in Tea Plant(Camellia sinensis) by Using cDNA Microarray

采用基因芯片技术对龙井群体中紫芽资源和绿芽资源进行分析,探索茶树紫化相关的差异表达基因。结果检测到差异表达基因43个,其中上调表达基因17个,下调表达基因26个。以基因芯片中紫芽资源上调基因TC0002e03和下调基因TL016D09、TL011D06,及不变基因TL022H08、TL024B05为材料,用实时荧光定量方法验证基因芯片的结果,二者完全相符。根据基因芯片的实验结果,采用数据库查询方式对43个差异表达基因进行功能注释,结果表明差异表达基因主要与能量代谢、次生代谢和转录调控等分子功能有关,特别是在差异表达基因中还包含两个与花青素代谢途径直接相关的基因,苯丙氨酸解氨酶和花青素还原酶基因,同绿芽资源相比,它们在紫色资源中分别下调3.44倍和上调2.09倍;同时还筛选到两个可能调控花青素合成的转录因子MYB蛋白和WD40蛋白,分别上调2.25倍和2.54倍。这些研究结果将为深入理解茶树芽叶的紫化机理,克隆相关基因打下基础。

Young shoots purple-related differentially expressed genes of tea plant have been found in purple and green shoots line of Longjing Qunti by cDNA microarray technique.There were 43 differentially expressed genes relating to purple shoots,among them 17 were up-regulated and 26 were down-regulated genes.Three differentially expressed genes and two no change genes were selected to verify the results of cDNA microarray hybridizations.The result of real time RT-PCR analysis was consistent with that of cDNA microarray.Then all of the differentially expressed genes were annotated functionally by Blast X search against the NCBI non-redundant protein databases.The molecular function of differentially expressed genes mainly included energy metabolism,secondary metabolism and transcriptional regulation.Especially two genes and two transcription factors involved in the biosynthesis pathway of anthocyanidin were selected from the results of cDNA microarray hybridizations.The phenylalanine ammonia lyase gene,MYB protein,WD40-like protein,and anthocyanidin reductase gene showed down-regulated 3.44,2.25,2.54 folds and up-regulated 2.09 folds,respectively.This study establishes a basis for further understanding the purple mechanism of tea young shoots and related gene cloning.