Abstract: Anthocyanins are water-soluble pigments which widely exist in plants. As strong free radical scavengers, they have many health benefical functions from anti-inflammatory, anti-oxidation, blood pressure lowering to hypoglycemic effect. The purple tea plants are a kind of specific tea germplasm rich in anthocyanins. More and more attentions had been focused on research and utilization of purple tea plants. In order to understand the molecular mechanism of anthocyanin biosynthesis in purple buds of tea, RNA-seq and bioinformatic analysis were performed using purple-buds cultivar 9803 and green-buds cultivar 9806 bred by Hunan Agricultural University, Changsha, China. Totally 42 unigenes were identified to be involved in anthocyanin biosynthetic pathway, including 34 genes registered in the GenBank database and 8 genes not reported. KEGG pathway analysis showed that differentially expression genes annotated to five metabolic pathways, including flavonoid biosynthetic pathway, lignin biosynthesis pathway, flavone and flavonol biosynthesis pathway, brassinosteroid biosynthesis pathway and encoding transcription factors. The expression profiles of differentially expressed genes by qRT-PCR were consistent with transcriptome sequencing results, demonstrating the sequencing results were reliable. In summary, many differentially expressed genes related to anthocyanin biosynthesis in the purple buds of tea were identified, which laid the foundation for further investigation of the molecular mechanism of purple bud formation in tea plants.

Key words: tea plant, anthocyanin, differentially expressed genes, transcriptome sequencing, bioinformatics analysis