Open AccessRNA-sequencing analysis reveals betalains metabolism in the leaf of Amaranthus tricolor L.
Author(s) -
Shengcai Liu,
Xiao Zheng,
Junfei Pan,
Liyun Peng,
Chunzhen Cheng,
Wang Xiao,
Chunli Zhao,
Zihao Zhang,
Yuling Lin,
Xu XuHan,
Zhongxiong Lai
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0216001
Subject(s) - betalain , amaranth , biology , betanin , metabolic pathway , botany , transcriptome , amaranthaceae , chlorophyll , secondary metabolism , biological pigment , pigment , metabolism , biochemistry , gene , gene expression , biosynthesis , chemistry , organic chemistry , antioxidant
Amaranth plants contain large amounts of betalains, including betaxanthins and betacyanins. Amaranthin is a betacyanin, and its molecular structure and associated metabolic pathway differ from those of betanin in beet plants. The chlorophyll, carotenoid, betalain, and flavonoid contents in amaranth leaves were analyzed. The abundance of betalain, betacyanin, and betaxanthin was 2–5-fold higher in the red leaf sectors than in the green leaf sectors. Moreover, a transcriptome database was constructed for the red and green sectors of amaranth leaves harvested from 30-day-old seedlings. 22 unigenes were selected to analyze the expression profiles in the two leaf sectors. The RNA-sequencing data indicated that many unigenes are involved in betalain metabolic pathways. The potential relationships between diverse metabolic pathways and betalain metabolism were analyzed. The validation of the expression of 22 selected unigenes in a qRT-PCR assay revealed the genes that were differentially expressed in the two leaf sectors. Betalains were biosynthesized in specific tissues of the red sectors of amaranth leaves. Almost all of the genes related to betalain metabolism were identified in the transcriptome database, and the expression profiles were different between the red sectors and green sectors in the leaf. Amaranth plants consist of diverse metabolic pathways, and the betalain metabolic pathway is linked to a group of other metabolic pathways.