A MYB gene from wheat (Triticum aestivum L.) is up-regulated during salt and drought stresses and differentially regulated between salt-tolerant and sensitive genotypes.

Crop adaptation to abiotic stresses requires alterations in expression of a large number of stress protection genes and their regulators, including transcription factors. In this study, the expression levels of ten MYB transcription factor genes from wheat (Triticum aestivum) were examined in two recombinant inbred lines contrasting in their salt tolerance in response to salt or drought stress. Quantitative RT-PCR analysis revealed that four MYB genes were consistently up-regulated in the seedling roots of both genotypes under short-term salt treatment. Three MYB genes were found to be up-regulated in both genotypes under long-term salt stress. One MYB gene was up-regulated in both genotypes under both short- and long-term salt stress. Of these salt up-regulated MYB genes, one MYB gene (TaMYBsdu1) was markedly up-regulated in the leaf and root of wheat under long-term drought stress. In addition, TaMYBsdu1 showed higher expression levels in the salt-tolerant genotype than in the susceptible genotype under salt stress. These data suggest that TaMYBsdu1 is a potentially important regulator involved in wheat adaptation to both salt and drought stresses.