A gene controlling variation in Arabidopsis glucosinolate composition is part of the methionine chain elongation pathway.

Published

Journal Article

Arabidopsis and other Brassicaceae produce an enormous diversity of aliphatic glucosinolates, a group of methionine (Met)-derived plant secondary compounds containing a beta-thio-glucose moiety, a sulfonated oxime, and a variable side chain. We fine-scale mapped GSL-ELONG, a locus controlling variation in the side-chain length of aliphatic glucosinolates. Within this locus, a polymorphic gene was identified that determines whether Met is extended predominantly by either one or by two methylene groups to produce aliphatic glucosinolates with either three- or four-carbon side chains. Two allelic mutants deficient in four-carbon side-chain glucosinolates were shown to contain independent missense mutations within this gene. In cell-free enzyme assays, a heterologously expressed cDNA from this locus was capable of condensing 2-oxo-4-methylthiobutanoic acid with acetyl-coenzyme A, the initial reaction in Met chain elongation. The gene methylthioalkylmalate synthase1 (MAM1) is a member of a gene family sharing approximately 60% amino acid sequence similarity with 2-isopropylmalate synthase, an enzyme of leucine biosynthesis that condenses 2-oxo-3-methylbutanoate with acetyl-coenzyme A.

Full Text

Duke Authors

Cited Authors

  • Kroymann, J; Textor, S; Tokuhisa, JG; Falk, KL; Bartram, S; Gershenzon, J; Mitchell-Olds, T

Published Date

  • November 2001

Published In

Volume / Issue

  • 127 / 3

Start / End Page

  • 1077 - 1088

PubMed ID

  • 11706188

Pubmed Central ID

  • 11706188

Electronic International Standard Serial Number (EISSN)

  • 1532-2548

International Standard Serial Number (ISSN)

  • 0032-0889

Digital Object Identifier (DOI)

  • 10.1104/pp.127.3.1077

Language

  • eng