外源抗坏血酸引发对NaCl胁迫下燕麦种子萌发及幼苗抗氧化性能的影响OA

To investigate the effects of priming with exogenous ascorbic acid(AsA)on the antioxidant per-formance of oat(Avena sativa)seedlings under different degrees of salt stress,oat seeds were primed with AsA solutions at concentrations of 0(CK),1,2,and 4 mmol/L for 24 h.Standard germination test was conducted subsequently under NaCl stress(0,75,and 150 mmol/L),and on the 10th day of germination,the activities of antioxidant enzymes and the levels of lipid peroxidation in the seedlings were measured.The results showed that germination percentage,germination index,and seedling vigor index of oat seeds were inhibited under 75 and 150 mmol/L NaCl stress,while mean germination time was prolonged,and H2O2 and malondialdehyde(MDA)contents increased significantly.The effect of exogenous AsA priming was concentration dependent.Treatment with 1 mmol/L AsA effectively promoted germination of oat seeds and enhanced antioxidant capac-ity of the seedlings under NaCl stress,whereas the 4 mmol/L treatment had the opposite effect.Compared with CK,priming with 1 mmol/L AsA significantly increased the germination percentage and germination index of oat seeds under 75 mmol/L NaCl stress.Meanwhile,the activities of antioxidant enzymes in the seed-lings were significantly enhanced,and H2O2 and MDA content were significantly reduced.Therefore,priming with 1 mmol/L exogenous AsA can be used as an effective approach to improve the germination of oat seeds and the antioxidant performance of the seedlings under 75 mmol/L NaCl stress.