S-nitrosylation of SlAPX Is Involved in Alleviating Oxidative Damage in Transgenic Tobacco under Nitrate Stress

Nitric oxide (NO) modulates plant response by post-translationally modifying proteins, mainly through S-nitrosylation. Ascorbate peroxidase (APX) in the ascorbate-glutathione (AsA-GSH) cycle participates removal of hydrogen peroxide (H2O2). However, relationship between S-nitrosylation and role tomato APX (SlAPX) under nitrate stress is still unclear. In this study, enzyme activity, mRNA expression, level SlAPX were significantly increased roots after treatment. protein could be S-nitrosylated S-nitrosoglutathione vitro, activity was The overexpressed tobacco plants grew better than wild type (WT) stress. Meanwhile, transgenic showed lower reactive oxygen species malondialdehyde content, higher APX, monodehydroascorbate reductase, glutathione reductase activities, ascorbic acid/dehydroascorbic acid, reduced glutathione/oxidized ratio, proline, soluble sugar contents those WT Moreover, seeds tolerance to methyl viologen induced oxidative compared with WT. NO accumulation Our results provide novel insights into mechanism modulation excess involving modification.