title: Shift in polyphenol profile and sublethal phenotype caused by silencing of anthocyanidin synthase in apple (Malus sp.).
abstract: We have investigated the consequences of blocking anthocyanin biosynthesis by silencing a key enzyme, anthocyanidin synthase, in transgenic plants of a red-leaved apple cultivar. This is complementary to a previous study of induction of anthocyanin biosynthesis by overexpressing a heterologous transcription factor. Analysis of these opposite phenotypes allows one to study anthocyanin functions in apple and to test the influence of the genetic manipulation on other, related metabolites. As expected, anthocyanin biosynthesis was almost completely blocked and this was accompanied by a shift in the profile of flavonoids and related polyphenols. Most interestingly, a rise in epicatechin was found. A severe reduction of viability by necrotic leaf lesions was also observed, suggesting an essential function of anthocyanins in apple.
authors.affiliation: Institute of Biological Production Systems, Leibniz University of Hannover, Herrenhaeuser Str. 2, 30419, Hannover, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Szankowski
authors.forename: Henryk
authors.initials: H
authors.lastname: Flachowsky
authors.forename: Houhua
authors.initials: H
authors.lastname: Li
authors.forename: Heidrun
authors.initials: H
authors.lastname: Halbwirth
authors.forename: Dieter
authors.initials: D
authors.lastname: Treutter
authors.forename: Ionela
authors.initials: I
authors.lastname: Regos
authors.forename: Magda-Viola
authors.initials: MV
authors.lastname: Hanke
authors.forename: Karl
authors.initials: K
authors.lastname: Stich
authors.forename: Thilo C
authors.initials: TC
authors.lastname: Fischer
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis / Q000502:physiology; D002392:Catechin / Q000378:metabolism; D005419:Flavonoids / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D027845:Malus / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D010105:Oxygenases / Q000235:genetics*; D010636:Phenols; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000378:metabolism; D059808:Polyphenols; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D005419:Flavonoids; D010636:Phenols; D010940:Plant Proteins; D059808:Polyphenols; D012333:RNA, Messenger; D002392:Catechin; D010105:Oxygenases; C118159:anthocyanidin synthase