Chromosomal location and expression of a herbicide safener-regulated glutathione S-transferase gene in Triticum aestivum and linkage relations in Hordeum vulgare

The chomosomal location of a glutathione S-transferase (GST) gene was determined in both hexaploid wheat (Triticum aestivum) and barley (Hordeum vulgare). The GST cDNA used to map the gene was cloned from the diploid wheat Triticum tauschii. GST loci were located on the short arms of chromosomes 6A, 6B, and 6D in T. aestivum and also on the short arm of chromosome 6H in H. vulgare. The GST locus in barley was absolutely linked to the RFLP marker E148A and was located 0.8 cM proximal to the RFLP marker ABC169B on barley chromosome 6H. At least two copies of the GST gene were present in each of the T. aestivum A, B, and D genomes, and a homologous GST gene was present as a single-copy gene in the barley genome. GST mRNA transcripts were not detected in RNA isolated from shoots of control (unsafened) seedlings of T. tauschii or T. aestivum. It was determined that the expression of the GST gene was regulated by herbicide safenet treatment in T. tauschii and T. aestivum by detecting safener-increased GST mRNA transcript levels.