Isolation of a Zeta class wheat glutathione S-transferase gene

A new Zeta class glutathione S-transferases (GST) gene, pGST, has been clon ed from wheat for the first time by the differential display PCR (DD-PCR) m ethod. The genomic sequence of pGST, TA-GSTZ1, contains nine exons that enc ode a polypeptide of 213 amino acids and eight introns. The deduced amino a cid sequence of TA-GSTZ1 as well as the exon:intron placement are more simi lar to the GSTs of the Zeta class than to the two wheat GSTs reported earli er. The pGST cDNA gene product expressed in Escherichia coli and purified b y affinity chromatography showed typical Zeta class GST and glutathione per oxidase activities. Sequence polymorphism in the 3' untranslated region (UT R) of TA-GSTZ1 gene in wheat has been discovered. In this study, an 89 bp s equence is present in the 3' UTR of TA-GSTZ1 gene in 16 wheat cultivars but absent in the other five. Although the biological importance of this polym orphism is unknown, it can be useful as a genetic marker in wheat breeding. (C) 1999 Elsevier Science B.V. All rights reserved.