Abstract

Comparative gene expression analysis was carried out to identify salt-stress responsive genes in T. aestivum and cytogentic stocks derived from T. aestivum x Lophopyrum elongatum crosses. A microarray consisting of 5728 cDNA amplicon probes was used in two gene expression profiling experiments. The first experiment examined the transcriptional profile of roots of the T. aestivum cultivar Norstar treated with 150 mM NaCl + 15mM CaCl 2 over a time course of 72 hours. The microarray analysis with Norstar revealed that there are 229 genes with significantly altered expression in salt treated plants. The second experiment compared gene expression profiles in wheat and wheat derivatives with different degrees of salt tolerance. Comparisons were made of roots of 150 mM NaCl + 150 mM CaCl 2 treated Chinese spring wheat, the amphiploid derived from a Chinese Spring Wheat x L elongatum cross and the disomic substitution line 3E(3A) of Chinese Spring in which chromosome 3A of wheat was replaced with chromosome 3E of L. elongatum. The analysis revealed that there are 212 genes that are significantly regulated in at least one genotype under salt stress and 42 genes have differences in regulation under salt stress between genotypes indicated by significant genotype by treatment interaction. Microarray analysis provided a practical tool for monitoring salt responsive genes in both experiments.