水杨酸促进盐胁迫条件下水稻种子萌发的机理研究

Study on Mechanism of Salicylic Acid on the Promotion of Rice Seeds Germination under Salt Stress

以水稻为材料,研究了0,0.25,0.50,1.00,2.50,5.00 mmol/L 6个浓度梯度的水杨酸(SA)对盐胁迫下水稻种子萌发及其抗氧化能力的影响,以探讨SA调控植物响应盐胁迫的机理。结果表明,正常条件下,各浓度SA均延缓水稻种子萌发,且具有浓度依赖效应。但在盐胁迫(150 mmol/L NaCl)条件下,低浓度(0.25,0.50 mmol/L)SA能促进水稻萌发,而较高浓度(1.00,2.50,5.00 mmol/L)SA却延迟甚至抑制其萌发。其中,0.50 mmol/L SA明显降低了盐胁迫下萌发种子中的丙二醛和过氧化氢含量,提高了过氧化物酶和超氧化物歧化酶活性及谷胱甘肽含量。结果说明,低浓度SA通过提高盐胁迫下抗氧化能力来促进水稻种子萌发。

In order to explore the mechanism of salicylic acid （SA） in the regulation of plant responses to salt stress, the effects of 0,0.25,0.50,1.00,2.50,5.00 mmol/L SA on germination and antioxidant capacity of rice were studied. The results showed that seeds germination was delayed by various SA under natural growth condition. However,under salt stress,seeds germination was promoted by the lower concentration （0.25,0.50 mmol/L） SA but delayed by the higher concentration （1.00,2.50,5.00 mmol/L） SA 0.50 mmol/L SA decreased significantly malondialdehyde and hydrogen peroxide content and increased the activities of peroxidase and superoxide dismutase and glutathione content. The results suggested that the lower concentration SA could promote rice seeds germination under salt stress by increasing antioxidant capacity.