Effect of long‐term salt stress on antioxidative enzyme activities of NyPa Forage (Distichlis spicata var.yensen‐4a)and tall fescue(Festuca arundinacea Schreb)

摘要

Salinization plays a major role in soil degradation.It affects 19.5% of irrigated and 2.1% of dry agriculture land existing on the globe, including 38.5 million ha that are salt‐affected to various degrees in China (FAO,2000).Na＋ imposes both ionic and osmotic stresses on plants, while the injurious osmotic effects and ionic toxicity lead to the generation of oxidative stress ( Hernandez and Almansa, 2002).To escape from the toxicity of activated oxygen species (AOS), plants have developed a complex antioxidative defense system, including antioxidant enzymes such as ascorbate peroxidase ( APX ), superoxide dismutase (SOD) and catalase (CAT).