Analysis of transcriptome sequencing and related genes of flavonoid biosynthesis from Anoectochilus roxburghii

Transcriptome sequencing was performed for the first time on Anoectochilus roxburghii(AR)in different harvesting periods using RNA-seq high-throughput sequencing technique, and the results were verified and analyzed by Q-PCR and HPLC. A total of 51, 370 genes were obtained by transcriptome sequencing and annotated to the database of Nr, GO, Swiss-Prot, KEGG and KOG. The species that were sequenced according to the homology sequence were the same as AR monocotyledon plants. Through comparison of AR transcriptome in different periods, it was found that the differences were mainly in flavonoid biosynthesis-related genes. The expression levels of flavonoid biosynthesis-related genes(trans-cinnamate 4-monooxygenase, caffeoyl-CoA O-methyltransferase, chalcone synthase, flavonol synthase, shikimate O-hydroxycinnamoyltransferase and flavonoid 3′, 5′-hydroxylase)were verified by Q-PCR, and the results were consistent with those of transcriptome sequencing. The contents of 6 flavonoids(rutin, isoquercitrin, narcissin, quercetin, kaempferol and isorhamnrtin)were determined by HPLC. The results showed that the expression of flavonoid synthetic gene in AR increased with the growth time, and the variation trend of flavonoid compound content and gene expression were basically consistent. Combined with transcriptome data, the biosynthetic pathway of flavonoid content in AR was plotted. This study provides important genetic resources for the key genes of flavonoid synthesis in AR and the biosynthesis of flavonoids, as well as the basis for the development of its medicinal value.