Transcriptome analysis identified genes involved in anthocyanin biosynthesis in Rainbow bamboo (Indosasa hispida MeClure cv. ‘Rainbow’)

Rainbow bamboo (Indosasa hispida) is an ornamental plant, which contains unique red to purple anthocyanin in its culm. However, the biosynthesis and function of anthocyanin in bamboo remains unclear. In this study, RNA-seq was used to investigate the transcriptome of the species and compare the gene expression profiles of red and white culms. The expression levels of genes involved in the anthocyanin biosynthesis pathway were detected using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). In total, 5.92 billion reads were obtained from the culm of Rainbow bamboo, which were assembled into 60,716 unigenes. qRT-PCR showed that the expression levels of anthocyanin biosynthesis-related genes in the red and white culms were higher than that in green leaves and that their levels in the red culm without sheath were higher than that in the white culm with sheath. Transcriptome analysis and qRT-PCR showed that the differences in the expression of genes encoding chalcone isomerase (CHI), dihydroflavonol reductase (DFR), flavonoid 3'-hydroxylase (F3'H), and anthocyanidin 3-O-glycosyltransferase (A3GT) between the culm and leaf were significant. This implies that CHI, DFR, F3'H, and A3GT play important roles in anthocyanin synthesis and accumulation in the culm of Rainbow bamboo.