Differential Regulation of Anthocyanins in Green and Purple Turnips Revealed by Combined De Novo Transcriptome and Metabolome Analysis

International Journal of Molecular Sciences

Huifang Liu¹  Qian Lou²  Hao Wang³  Hongmei Zhuang⁴  Zhonghua Tang⁴  Qiang Wang⁴  Hongwei Han⁴  Yanming Ma⁵ 

[1] F University, Yangling 712100, China;;College of Horticulture, Northwest A &Institute of Genetic Resources, Xinjiang Academy of Agricultural Science, Urumqi 830091, China;Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China;Key Laboratory of Plant Ecology, Northeast Forestry University, Harbin 150040, China;

关键词: pigment;    turnip;    gene expression;    antioxidant;    nutritional quality;   

DOI  :  10.3390/ijms20184387

来源: DOAJ

【 摘 要 】

Purple turnip Brassica rapa ssp. rapa is highly appreciated by consumers but the metabolites and molecular mechanisms underlying the root skin pigmentation remain open to study. Herein, we analyzed the anthocyanin composition in purple turnip (PT) and green turnip (GT) at five developmental stages. A total of 21 anthocyanins were detected and classified into the six major anthocynanin aglycones. Distinctly, PT contains 20 times higher levels of anthocyanins than GT, which explain the difference in the root skin pigmentation. We further sequenced the transcriptomes and analyzed the differentially expressed genes between the two turnips. We found that PT essentially diverts dihydroflavonols to the biosynthesis of anthocyanins over flavonols biosynthesis by strongly down-regulating one flavonol synthase gene, while strikingly up-regulating dihydroflavonol 4-reductase (DFR), anthocyanidin synthase and UDP-glucose: flavonoid-3-O-glucosyltransferase genes as compared to GT. Moreover, a nonsense mutation identified in the coding sequence of the DFR gene may lead to a nonfunctional protein, adding another hurdle to the accumulation of anthocyanin in GT. We also uncovered several key members of MYB, bHLH and WRKY families as the putative main drivers of transcriptional changes between the two turnips. Overall, this study provides new tools for modifying anthocyanin content and improving turnip nutritional quality.

【 授权许可】

Unknown