| الوصف: |
Nitric oxide (NO) plays an important role in plant growth, development, and stress responses. The exogenous NO donor sodium nitroprusside (SNP) increased the plant height, root length, and biomass of tomato seedlings under nitrate stress, especially 100 μM SNP. The reactive oxygen species (ROS) and malondialdehyde (MDA) contents were decreased, while the antioxidant enzyme activities, ascorbate and glutathione contents, and expression of SlTrxh, SlNTRB, SlTpx were increased in tomato after SNP and nitrate stress treatment, compared with nitrate stress. The tomato plants showed shorter root length, more MDA and ROS contents after the NADPH-dependent thioredoxin reductase (NTR) inhibitor Auranofin (ANF) was added, suggesting that ANF inhibited the alleviating effect of NO under nitrate stress. The NO and S-nitrosothiol (SNO) contents and the SlNR transcript levels were decreased and the expression of SlGLB, SlGSNOR was increased after NO and nitrate stress treatment. The S-nitrosylated level in tomato roots was increased after nitrate stress. The SlMDHAR, SlTrxh, and SlNTRB protein were S-nitrosylated after NO and nitrate stress treatment. These results suggested that key enzymes in ascorbate-glutathione cycle and Trx system played an important role in alleviating the effect of NO in tomato seedlings under nitrate stress involving the S-nitrosylation modification. |
