Functional Diversification of the Dihydroflavonol 4-Reductase from Camellia nitidissima Chi. in the Control of Polyphenol Biosynthesis

Genes

Xingwen Zhou¹  Zhengqi Fan²  Lina Jiang²  Jiyuan Li²  Ran Tong²  Hengfu Yin² 

[1] College of Biology and Pharmacy, Yulin Normal University, Yulin 537000, China;State Key Laboratory of Tree Genetics and Breeding, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China;

关键词: floral pigmentation;    dihydroflavonol 4-reduetase;    Camellia nitidissima Chi.;    polyphenols;    anthocyanins;   

DOI  :  10.3390/genes11111341

来源: DOAJ

【 摘 要 】

Plant secondary metabolism is complex in its diverse chemical composition and dynamic regulation of biosynthesis. How the functional diversification of enzymes contributes to the diversity is largely unknown. In the flavonoids pathway, dihydroflavonol 4-reductase (DFR) is a key enzyme mediating dihydroflavanol into anthocyanins biosynthesis. Here, the DFR homolog was identified from Camellia nitidissima Chi. (CnDFR) which is a unique species of the genus Camellia with golden yellow petals. Sequence analysis showed that CnDFR possessed not only conserved catalytic domains, but also some amino acids peculiar to Camellia species. Gene expression analysis revealed that CnDFR was expressed in all tissues and the expression of CnDFR was positively correlated with polyphenols but negatively with yellow coloration. The subcellular localization of CnDFR by the tobacco infiltration assay showed a likely dual localization in the nucleus and cell membrane. Furthermore, overexpression transgenic lines were generated in tobacco to understand the molecular function of CnDFR. The analyses of metabolites suggested that ectopic expression of CnDFR enhanced the biosynthesis of polyphenols, while no accumulation of anthocyanins was detected. These results indicate a functional diversification of the reductase activities in Camellia plants and provide molecular insights into the regulation of floral color.

【 授权许可】

Unknown