Enhanced antioxidative responses of a salt-resistant wheat cultivar facilitate its adaptation to salt stress
Wheat cultivars capable of accumulating minerals under salt stress are of considerable interest for their potential to improve crop productivity and crop quality. This study addressed the role of antioxidative enzymes in the responses of a salt-resistant wheat cultivar Cang 6001 to high-salt stress compared to a salt-sensitive wheat cultivar Shi 4185. Under NaCl stress, oxidative damage was more severe and the potassium (K), calcium (Ca), zinc (Zn), and iron (Fe) accumulations were lower in Shi 4185 seedlings than in Cang 6001 seedlings. Supplementation with antioxidants such as ascorbic acid (AsA) and N-acetyl-L-cysteine (NAC) increased Zn/Fe contents in wheat seedlings, indicating that the increased accumulation of Zn and Fe under salt stress in Cang 6001 seedlings was at least partially related to the depressed level of reactive oxygen species (ROS). Under salt stress, the superoxide dismutase (SOD) activity was higher in Cang 6001 than in Shi 4185. Semi-quantitative real-time polymerase chain reaction (RT-PCR) analysis indicated that the transcripts of cytoplasmic Cu/Zn-SOD and Mn-SOD were higher in Cang 6001 than in Shi 4185 under salt stress. Our results indicate that during salt stress, elevated SOD activity protected seedlings from ROS damage and may improve micronutrition elements uptake. The possible involvement of SOD activity in Zn/Fe accumulations under salt stress was discussed.
Key words: Anti-oxidative enzymes, wheat, salt, micronutrition elements.