Sodium nitroprusside modulates gene expression involved in glutathione synthesis in Zea mays leaves

To investigate a possible involvement of nitric oxide in gene regulation of glutathione and flavonoid synthesis pathways, maize seedlings were treated with sodium nitroprusside (SNP), a NO donor, and apocynin (APO), an inducer of NO production. After 12-h treatment, the transcripts of gamma-glutamylcysteine synthetase (gamma-ecs), glutathione synthetase (gsh-s), chalcone synthase (chs), phenylalanine ammonia lyase (pal.1), myb-related protein P (P1) and actin 1 (act) genes were quantified in maize leaves by real time PCR, using alpha-tubulin as standard transcript. The level of gamma-ecs and gsh-s transcripts in maize leaves were increased 9-fold and 12-fold, respectively, following SNP treatment, while after APO treatment, those transcripts were not significantly different from control plants. SNP-treated maize leaves did not show significant changes in pal.1 and chs expression. NO content in maize leaves was increased in SNP and APO treated plants in comparison to control plants. In conclusion, our experiments suggested that genes involved in glutathione synthesis could be modulated by SNP in maize leaves. On the other hand, APO had no effect on gamma-ecs and gshs gene expression.