Abstract:In order to explore different anthocyanidins and their synthesis regulator genes in Gynura bicolor leaves, we sequenced the transcriptomes of 2 G. bicolors including the purple leaves and the green leaves in control by Illumina HiSeq 2500 platform. At the same time, previously reported 6 kinds of anthocyanidins were detected by HPLC and 6 differential expressed genes were identified by the RTPCR.The aim is to reveal its unique anthocyanidins and key gene information for its synthesis and regulation in G. bicolor. The results showed that: (1) 14 unigenes related to anthocyanidins and 34 unigenes related to their synthesis regulator genes were obtained. There were 6 differential expressed genes from all of these genes between the 2 G. bicolors with purple and green leaves, which were 4 significant downregulated genes including pelargonidin (c11692), cyanidin (c42112), anthocyanidin synthase (c38551), flavonoid 3Oglucosyltransferase (c9064) and 2 significant upregulated genes including dihydroflavonol (c35961), flavonoid 3Oglucosyltransferase (c20283). (2) The up or downexpression trend of these 6 genes agreed very well with the testing by the RTPCR. However, the expression trend by transcriptome sequencing was more significantly different than that by qRTPCR. (3) According to the HPLC detection, the result showed that there were not 4 kinds of anthocyanidins such as delphinidin, peonidin, petunidin and malvidin in G. bicolor. However, the purple leaves had significantly higher content of cyanidin (62.21 mg/kg) than that in green leaves (6.86 mg/kg). At the same time, the content of pelargonidin was below 0.43 mg/kg in 2 G. bicolors. So this study inferred that the reason why the levels of the 2 kinds of anthocyanidins including cyanidin and pelargonidin were decreased significantly in green G. bicolor was the 4 anthocyanin synthesis regulator genes involved in positive regulatory genes like an anthocyanidin synthase and a flavonoid 3Oglucosyltransferase, negative regulatory genes like a dihydroflavonol and a flavonoid 3Oglucosyltransferase.