Comparison of antioxidant enzyme activity and gene expression in two new spring wheat cultivars treated with salinity

This study aimed to analyze element content, antioxidative response, and related gene expression in two new wheat (Tritium aestivum L.) cultivars Longchun 30 and Longchun 27 when exposed to different NaCl concentrations. Low NaCl concentration (25 mM) promoted root growth and decreased malondialdehyde (MDA) content and relative conductivity (REC) in Longchun 30. Differently, higher salinity stress (100 and 200 mM NaCl) inhibited root growth and increased MDA content and REC in both cultivars. Under salt stress, the increment of Na content in the roots and leaves and the reduction of Ca content in the roots were more remarkable in Longchun 27 than in Longchun 30. In contrast, the potassium content decreased in the roots but did not significantly change in the leaves in both cultivars under salinity. When the seedlings were exposed to salinity, the increases of superoxide dismutase (SOD) and catalase (CAT) activities in Longchun 27 roots were associated with high isoenzymes abundance and high TaCu/ZnSOD, TaMnSOD and TaCAT expression. Meanwhile, total peroxidase (POD) activity induced by NaCl treatment coincided with the changes of TaPOD expression and isoenzyme abundance in both cultivars. Besides, the inhibition of activities of apoplastic antioxidant enzymes, cell wall-bound POD, diamine oxidase, and polyamine oxidase was observed in salinity-stressed roots of both cultivars. Taken together, cv. Longchun 30 might be more suitable for growing in salinity environment in comparison with Longchun 27.