Transcriptome analysis for genes involved in fructan biosynthesis in the Jerusalem artichoke (Helianthus tuberosus L.)

Abstract

Jerusalem artichoke (Helianthus tuberosus L.) is a fructan-accumulating plant and an industrial raw material for fructan production. However, the genetic mechanism of fructan biosynthesis remains unclear. Therefore, this study performed transcriptome analysis to determine the genetic differences between two Jerusalem artichoke genotypes and different fructan contents. Approximately 19.73 Gb of clean data were obtained after filtering, and a total of 164,006 unigenes were annotated based on GO, KOG and KEGG functional classification. Then, seven homologous genes involved in fructan biosynthesis were obtained by homology comparison. CL11458.Contig2 and CL7122.Contig14 were candidate genes for sucrose:sucrose 1-fructosyl-transferase (1-SST) and fructan:fructan 1-fructosyl-transferase (1-FFT), respectively. The genetic relationship between SST and SST from artichoke in the phylogenetic tree are relatively close, and FFT is located in the same branch as FFT from ‘Qingyu No.1’ Jerusalem artichoke and Viguiera. SST and FFT were the main regulatory genes of fructan accumulation in Jerusalem artichoke. Therefore, this study successfully identified major genes involved in fructan biosynthesis. Future studies should aim to prove the role of each candidate gene in fructan biosynthesis in Jerusalem artichoke.