外源SA对盐胁迫下冬小麦幼苗生长的缓解效应及其机理

Effects and mechanisms of exogenous SA alleviating the growth of winter wheat seedlings under salt stress

为明确外源SA缓解冬小麦盐胁迫的适宜浓度。本研究以冬小麦(Triticum aestivum L.)品种‘山农22’为试验材料,水杨酸(SA)作为调控物质,采用室内营养液培养方法,研究5个浓度的SA(50,100,200,300和500μmol/L)对120mmol/L NaCl胁迫下冬小麦幼苗生长、生理特性的影响。结果表明:添加SA能够缓解盐胁迫对小麦造成的损害。200μmol/L SA可以显著提高小麦叶片光合色素含量、根系活力,促进小麦的生长发育;200μmol/L SA可显著提高抗氧化酶活性,增加游离脯氨酸和可溶性蛋白等渗透调节物质含量,缓解膜质过氧化伤害。本研究所采用的SA浓度中,以200μmol/L SA对冬小麦幼苗盐胁迫的缓解效果最佳。

In order to clarify the effects and mechanisms of exogenous SA on the growth of winter wheat seedlings under salt stress and optimize the concentration of exogenous SA alleviating the salt stress.In this study,a hydroponic experiment was carried out on cultivating wheat (Triticum aestivum L.) by using SA as regulatory substance to explore the effects of extraneous SA at 5 concentrations (50,100,200,300 and 500 μmol/L) on the growth and physiological properties of wheat under salt stress (120 mmol/L NaCl).The results showed that exogenous SA alleviated salt stress effects in winter wheat seedlings.The alleviating effects were not obvious at 50,100,300 and 500 μmol/L SA concentrations,while the concentration of 200 μmol/L SA significantly enhanced the chlorophyll content and root activity of wheat seedling.The 200 μmol/L SA treatment significantly improved antioxidant enzymes (SOD,POD,CAT) activities and improved proline content and soluble protein content to alleviate lipid peroxidation damage.In conclusion,the effect of 200 μmol/L SA was the best in alleviating salt stress effects of winter wheat seedlings.