DOI：https://doi.org/10.1016/j.indcrop.2022.115529

发表期刊：Industrial Crops & Products

链接：https://doi.org/10.1016/j.indcrop.2022.115529

Sainan Ma¹, Ruchang Hu¹, Jieyu Ma, Jinwan Fan, Feifei Wu, Yang Wang, Linkai Huang, Guangyan Feng, Dandan Li, Gang Nie *, Xinquan Zhang *

Abstract:Anthocyanin and proanthocyanidin (PA) are plant natural products beneficial to human and livestock health.In particular, the legume forage with proper PA contents canprevent lethal pasture bloat in ruminant animals.‘Purple’ white clover shows abundant purple pigment and a higher PA content than that of green‘Haifa’ white clover. To studythe mechanism underlying anthocyanin and PA biosynthesis in white clover, comparative transcriptomics and metabolomicsanalyses were performed with‘Purple’ and ‘Haifa’ white clover.Metabolic analyses revealed that pelargonidin may be the most important source of color in ‘Purple.’Cyanidin-3-O-(6''-O-p-coumaroyl)-glucoside, petunidin-3-O-(6''-O-p-coumaroyl)-rutinoside, and delphinidin-3-O-rutinoside-7-O-glucosidemightcontribute to PA biosynthesis. Additionally, 67 differentially expressed genes in anthocyanin and PA biosynthetic pathways were discovered between ‘Purple’ and ‘Haifa.’Among them,DFR(dihydroflavonol-4-reductase),LDOX/ANS(leucoanthocyanidin oxygenase/anthocyanidin synthase), (leucoanthocyanidin reductase),ANR(anthocyanidin reductase),andUFGT(UDPglucose:flavonoid-3-O-glucosyltransferase) may be keydeterminants of the differences in anthocyanin and PA biosynthesis.Finally,A hypothetical model of gene expression regulating the synthesis of PAs and anthocyanins in white clover was proposed, which couldprovide a molecular genetic basis for future candidate genes validation and breeding high-PA white clovercultivars.

A hypothetical model of gene expression regulating the synthesis of PAs and anthocyanins in white clover. (A) In white clover inflorescences. (B) In white clover leaves. The color of the arrow indicates the expression level of structural genes; the arrow on the left and the arrow below represent ‘Haifa’ and the arrow on the right and the arrow above represent ‘Purple.’ The black dotted line indicates that the direct correlation was uncertain.