|
|
||||||||
|
First published online September 29, 2006; 10.1104/pp.106.088104 Plant Physiology 142:1216-1232 (2006) © 2006 American Society of Plant Biologists Light-Induced Expression of a MYB Gene Regulates Anthocyanin Biosynthesis in Red Apples1Commonwealth Scientific and Industrial Research Organization, Plant Industry, Adelaide Laboratory, Waite Campus, Urrbrae, SA 5064, Australia (A.M.T., F.W.J., J.B., S.P.R., A.R.W.); and Department of Agriculture and Food Western Australia, Manjimup Horticultural Research Institute, Manjimup, WA 6258, Australia (S.R.J.)
Anthocyanins are secondary metabolites found in higher plants that contribute to the colors of flowers and fruits. In apples (Malus domestica Borkh.), several steps of the anthocyanin pathway are coordinately regulated, suggesting control by common transcription factors. A gene encoding an R2R3 MYB transcription factor was isolated from apple (cv Cripps' Pink) and designated MdMYB1. Analysis of the deduced amino acid sequence suggests that this gene encodes an ortholog of anthocyanin regulators in other plants. The expression of MdMYB1 in both Arabidopsis (Arabidopsis thaliana) plants and cultured grape cells induced the ectopic synthesis of anthocyanin. In the grape (Vitis vinifera) cells MdMYB1 stimulated transcription from the promoters of two apple genes encoding anthocyanin biosynthetic enzymes. In ripening apple fruit the transcription of MdMYB1 was correlated with anthocyanin synthesis in red skin sectors of fruit. When dark-grown fruit were exposed to sunlight, MdMYB1 transcript levels increased over several days, correlating with anthocyanin synthesis in the skin. MdMYB1 gene transcripts were more abundant in red skin apple cultivars compared to non-red skin cultivars. Several polymorphisms were identified in the promoter of MdMYB1. A derived cleaved amplified polymorphic sequence marker designed to one of these polymorphisms segregated with the inheritance of skin color in progeny from a cross of an unnamed red skin selection (a sibling of Cripps' Pink) and the non-red skin cultivar Golden Delicious. We conclude that MdMYB1 coordinately regulates genes in the anthocyanin pathway and the expression level of this regulator is the genetic basis for apple skin color.
1 This work was supported by a grant from the Department of Agriculture and Food Western Australia and Horticulture Australia Ltd. 2 Present address: Heidelberger Institut fuer Pflanzenwissenschaften, Im Neuenheimer Feld 360, D69120 Heidelberg, Germany. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Amanda R. Walker (mandy.walker{at}csiro.au). www.plantphysiol.org/cgi/doi/10.1104/pp.106.088104 * Corresponding author; e-mail mandy.walker{at}csiro.au; fax 61883038601. Received August 9, 2006; accepted September 7, 2006; published October 13, 2006. This article has been cited by other articles:
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ASPB Publications | PLANT PHYSIOLOGY | THE PLANT CELL | |
|---|---|---|---|