اثرهای حفاظتی سدیم نیتروپروساید بر تنش اکسیداتیو ناشی از نیکل در برگ‌های گیاهان گوجه فرنگی

In the present research, the interactive effects of nickel and sodium nitroprusside (SNP), a donor of nitric oxide (NO) on tomato plants were examined. 25-day-old tomato plants were exposed to different concentrations of NiCl2 . 6H2O (0, 0.25, 0.5 mM) and SNP (0, 0.1 mM) for 10 days. Treatment with Ni decreased dry weight of roots and shoots and reduced chlorophyll content in leaves. In Ni-treated plants, activity of antioxidant enzymes such as catalase, guaiacol peroxidase and ascorbate peroxidase significantly decreased in leaves, while, level of lipoxygenase (LOX) activity and malondialdehyde (MDA) content increased. The results indicated that Ni caused an oxidative stress in tomato plants. In Ni-stressed plants, application of SNP reduced root-to-shoot translocation of Ni and improved growth and chlorophyll content. Adding of SNP in the nutrient solution, increased the antioxidant enzymes activities and decreased LOX activity and MDA content in leaves of Ni-treated plants. Consequently, SNP markedly reduced Ni induced oxidative damage on tomato plants.