GAME9 regulates the biosynthesis of steroidal alkaloids and upstream isoprenoids in the plant mevalonate pathway

TitleGAME9 regulates the biosynthesis of steroidal alkaloids and upstream isoprenoids in the plant mevalonate pathway
Publication TypeJournal Article
Year of Publication2016
AuthorsCardenas, PD, Sonawane, PD, Pollier, J, Bossche, RVanden, Dewangan, V, Weithorn, E, Tal, L, Meir, S, Rogachev, I, Malitsky, S, Giri, AP, Goossens, A, Burdman, S, Aharoni, A
JournalNature Communications
Volume7
PaginationArticle Number: 10654
Date PublishedFEB
ISSN2041-1723
Abstract

Steroidal glycoalkaloids (SGAs) are cholesterol-derived molecules produced by solanaceous species. They contribute to pathogen defence but are toxic to humans and considered as anti-nutritional compounds. Here we show that GLYCOALKALOID METABOLISM 9 (GAME9), an APETALA2/Ethylene Response Factor, related to regulators of alkaloid production in tobacco and Catharanthus roseus, controls SGA biosynthesis. GAME9 knockdown and overexpression in tomato and potato alters expression of SGAs and upstream mevalonate pathway genes including the cholesterol biosynthesis gene STEROL SIDE CHAIN REDUCTASE 2 (SSR2). Levels of SGAs, C24-alkylsterols and the upstream mevalonate and cholesterol pathways intermediates are modified in these plants. Delta(7)-STEROL-C5(6)-DESATURASE (C5-SD) in the hitherto unresolved cholesterol pathway is a direct target of GAME9. Transactivation and promoter-binding assays show that GAME9 exerts its activity either directly or cooperatively with the SlMYC2 transcription factor as in the case of the C5-SD gene promoter. Our findings provide insight into the regulation of SGA biosynthesis and means for manipulating these metabolites in crops.

DOI10.1038/ncomms10654
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)11.329
Divison category: 
Biochemical Sciences