Monitoring of Transcriptional Responses in Roots of Six Wheat Cultivars during Mild Drought Stress

In order to study drought stress responses in roots during moderate water shortage, our group has designed an oligonucleotide microarray containing probes for genes annotated as either stress-related or general ones to examine six wheat cultivars. These include two drought-tolerant and four drought-sensitive genotypes, having different root morphology either during optimal or water-deficit stress conditions. After a two-week-long water withdrawal, no significant changes were detected in root weights but various trends were observed in the cultivars. These tendencies showed relevant correlations with expression kinetics of genes encoding proteins related to root growth and development. On the other hand, probes indicating variation in distinct genotypes mainly belonged to the group of stress-related genes which encode proteins that contribute to carbohydrate remodeling, osmoprotectant accumulation, amino acid metabolism, defense against oxidative stress, and regulation of transcription. Hence, these data allow us to focus on major metabolic processes involved in drought adaptation as well as provide a wide selection of candidate genes for further detailed studies.