title: The Balance of Expression of Dihydroflavonol 4-reductase and Flavonol Synthase Regulates Flavonoid Biosynthesis and Red Foliage Coloration in Crabapples.
abstract: Red leaf color is an attractive trait of Malus families, including crabapple (Malus spp.); however, little is known about the molecular mechanisms that regulate the coloration. Dihydroflavonols are intermediates in the production of both colored anthocyanins and colorless flavonols, and this current study focused on the gene expression balance involved in the relative accumulation of these compounds in crabapple leaves. Levels of anthocyanins and the transcript abundances of the anthocyanin biosynthetic gene, dihydroflavonol 4-reductase (McDFR) and the flavonol biosynthetic gene, flavonol synthase (McFLS), were assessed during the leaf development in two crabapple cultivars, 'Royalty' and 'Flame'. The concentrations of anthocyanins and flavonols correlated with leaf color and we propose that the expression of McDFR and McFLS influences their accumulation. Further studies showed that overexpression of McDFR, or silencing of McFLS, increased anthocyanin production, resulting in red-leaf and red fruit peel phenotypes. Conversely, elevated flavonol production and green phenotypes in crabapple leaves and apple peel were observed when McFLS was overexpressed or McDFR was silenced. These results suggest that the relative activities of McDFR and McFLS are important determinants of the red color of crabapple leaves, via the regulation of the metabolic fate of substrates that these enzymes have in common.
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Tian
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: Zhen-yun
authors.initials: ZY
authors.lastname: Han
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: YuJing
authors.initials: Y
authors.lastname: Hu
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Song
authors.affiliation: 1] Department of Plant Science and Technology, Beijing University of Agriculture, Beijing, China [2] Key Laboratory of New Technology in Agricultural Application of Beijing, Beijing University of Agriculture, Beijing, China.
authors.forename: Yuncong
authors.initials: Y
authors.lastname: Yao
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000872:Anthocyanins; D053898:Biosynthetic Pathways / Q000235:genetics; D005419:Flavonoids / Q000096:biosynthesis*; D005638:Fruit / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D027845:Malus / Q000201:enzymology* / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010858:Pigmentation / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D005419:Flavonoids; D010940:Plant Proteins; D012333:RNA, Messenger; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C056570:dihydroflavanol 4-reductase; C085313:flavonol synthase