基于高通量测序的“紫娟”茶树叶片miRNA分析

Analysis on mi RNA of Camellia sinensis(L.) O. Kuntze Using High-throughput Sequencing

＂紫娟＂是特异的茶树资源,含有丰富的次生代谢物儿茶素、花青素、黄酮等,其生物合成是由多条代谢途径通过相应的节点连在一起的网络途径,受到多种结构基因和调控基因的控制。Micro RNA又称miRNA,是一种非编码RNAs,能通过对基因表达的调控来调节植物生长、发育以及次生代谢等许多方面。本研究利用高通量测序技术分别构建了＂紫娟＂茶树芽、第二叶、开面叶、成熟叶的miRNA文库并进行测序,鉴定出已知的miRNA 126个,分为26个家族,预测到的新miRNA 119个。基于＂紫娟＂茶树转录组数据分析已知miRNA和新miRNA分的靶基因,分别预测到靶基因724条和2 285条。预测的靶基因大多为转录因子,包括调控次生代谢物花青素、黄酮类生物合成的MYB、b HLH转录因子等。这些注释信息的完成为后期研究miRNA在调控茶树叶片发育和次生代谢物的生物合成提供理论依据。

＂Zijuan＂is specific tea resource, is rich in secondary metabolites： anthocyanins, catechins, flavone,etc. The biosynthesis is a network pathway composed of multiple metabolic pathways by associated nodes, which is controlled by a variety of structural genes and regulatory genes. Micro RNAs（miRNAs）, a group of non-coding RNAs, play important roles in plant growth, development and secondary metabolism by regulating gene expression. In this study, four independent miRNA libraries of bud, second-leaf, open surface leaf and mature-leaf of Zijuan tea were constructed and sequenced with high-throughput sequencing. Further analysis identified 126 known miRNAs belonging to 26 families, and predicted 119 novel miRNAs. Based on the Camellia sinensis transcriptome data, 724 and 2 285 potential target genes were predicted for conserved and novel miRNAs, respectively. The predicted target genes were mostly transcription factors, which included MYB and b HLH transcription factors for regulating secondary metabolite anthocyanin and flavones biosynthesis. All the above results might lay the foundation for further studies on leaf development and biosynthesis of secondary metabolites of miRNA in tea plant.