Differential expression of rice GST genes in response to various abiotic and arsenate stress conditions. Hierarchical clustering of GST genes showing significant differential expression under at least one abiotic stress condition (A) or arsenate stress (B) is shown. The fold change values (Additional files 10, 11) in treated sample as compared to its corresponding mock-treated control sample were used for clustering. The color scale for fold change values is shown at the bottom. Venn diagram represents number of GST genes commonly or specifically regulated by various abiotic stress conditions. (C) Real-time PCR analysis of selected genes to validate their differential expression during various abiotic stress conditions. The mRNA levels for each gene in different tissue samples were calculated relative to its expression in control seedlings. The error bars represent standard deviation. DS, desiccation stress; SS, salt stress; CS, cold stress; ArS, arsenate stress. Azucena and Bala represent arsenate-sensitive and arsenate-resistant rice varieties, respectively.