Alternative Splicing Regulation of Anthocyanin Biosynthesis in var. Unveiled by PacBio Iso-Seq.

Although the pathway and transcription factor regulation of anthocyanin biosynthesis in tea plants [ (L.) O. Ktze] are known, post-transcriptional regulation mechanisms involved in anthocyanin accumulation have not been comprehensively studied. We obtained the full-length transcriptome of a purple cultivar ('Zijuan') and a normal green cultivar ('Yunkang 10#) of var. (Masters) showing different accumulation of anthocyanins and catechins through PacBio isoform sequencing (Iso-Seq). In total, 577,557 mapped full-length cDNAs were obtained, and 2,600 average-length gene isoforms were identified in both cultivars. After gene annotations and pathway predictions, we found that 98 key genes in anthocyanin biosynthesis pathways could have undergone alternative splicing (AS) events, and identified a total of 238 isoforms involved in anthocyanin biosynthesis. We verified expression of the , , , , , , , , , , , , , , , , , , , , genes and their AS transcripts using qRT-PCR. Correlation analysis of anthocyanin biosynthesis and gene expression results revealed that , , , , and are crucial AS transcripts for regulating anthocyanin biosynthesis in Our results reveal post-transcriptional regulation of anthocyanin biosynthesis in tea plants, and provide more new insights into the regulation of secondary metabolism.