Nitric oxide alleviates freezing stress by reducing oxidative injury in Citrumelo leaves
By: Mojdeh Nazarpour, Fariborz Zare Nahandi, Mohammad Reza Dadpour
Key Words: Citrumelo, Freezing stress, Oxidative stress, Sodium nitroprusside.
J. Bio. Env. Sci. 9(1), 390-399, July 2016.
Freezing stress causes economical losses of citrus in the world. Nitric oxide could alleviate this stress. In this study the effects of sodium nitroprusside (SNP) as NO donor (0, 0.1 and 1 mM) on temperature treatments (+9, -3, -6 and -9°C) were evaluated. Application of 0.1 mM SNP decreased the electrolyte leakage and lipid peroxidation of Citrumelo leaves signiﬁcantly. The highest antioxidant activity was detected in 0.1 mM SNP at -6 °C. Maximum content of total phenolics was at -9 °C and 0.1 mM SNP application. SNP also had positive effects on antioxidant enzymes activity. Superoxide dismutase, catalase and peroxidase had highest activity at -6°C with 0.1 mM SNP, and the highest activity of APX was in 0.1 mM SNP at -9°C. The results showed nitric oxide released from SNP increased the antioxidant capacity of Citrumelo leaves against freezing induced oxidative stress.