title: In planta anthocyanin degradation by a vacuolar class III peroxidase in Brunfelsia calycina flowers.
abstract: In contrast to detailed knowledge regarding the biosynthesis of anthocyanins, the largest group of plant pigments, little is known about their in planta degradation. It has been suggested that anthocyanin degradation is enzymatically controlled and induced when beneficial to the plant. Here we investigated the enzymatic process in Brunfelsia calycina flowers, as they changed color from purple to white. We characterized the enzymatic process by which B. calycina protein extracts degrade anthocyanins. A candidate peroxidase was partially purified and characterized and its intracellular localization was determined. The transcript sequence of this peroxidase was fully identified. A basic peroxidase, BcPrx01, is responsible for the in planta degradation of anthocyanins in B. calycina flowers. BcPrx01 has the ability to degrade complex anthocyanins, it co-localizes with these pigments in the vacuoles of petals, and both the mRNA and protein levels of BcPrx01 are greatly induced parallel to the degradation of anthocyanins. Both isoelectric focusing (IEF) gel analysis and 3D structure prediction indicated that BcPrx01 is cationic. Identification of BcPrx01 is a significant breakthrough both in the understanding of anthocyanin catabolism in plants and in the field of peroxidases, where such a consistent relationship between expression levels, in planta subcellular localization and activity has seldom been demonstrated.
authors.affiliation: Department of Ornamental Horticulture, Agriculture Research Organization, The Volcani Center, PO Box 6, Beit Dagan, 50250, Israel.
authors.forename: Gadi
authors.initials: G
authors.lastname: Zipor
authors.forename: Patrícia
authors.initials: P
authors.lastname: Duarte
authors.forename: Inês
authors.initials: I
authors.lastname: Carqueijeiro
authors.forename: Liat
authors.initials: L
authors.lastname: Shahar
authors.forename: Rinat
authors.initials: R
authors.lastname: Ovadia
authors.forename: Paula
authors.initials: P
authors.lastname: Teper-Bamnolker
authors.forename: Dani
authors.initials: D
authors.lastname: Eshel
authors.forename: Yishai
authors.initials: Y
authors.lastname: Levin
authors.forename: Adi
authors.initials: A
authors.lastname: Doron-Faigenboim
authors.forename: Mariana
authors.initials: M
authors.lastname: Sottomayor
authors.forename: Michal
authors.initials: M
authors.lastname: Oren-Shamir
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000378:metabolism*; D001483:Base Sequence; D035264:Flowers / Q000201:enzymology / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009195:Peroxidase / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein; D019657:Solanaceae / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D009195:Peroxidase
keywords: Brunfelsia calycina; anthocyanin degradation; flower pigmentation; vacuolar localization; vacuolar peroxidase