外源GSH对盐胁迫下番茄幼苗生长及抗逆生理指标的影响

采用营养液栽培法,研究外源谷胱甘肽(GSH)对NaCl胁迫下番茄幼苗生长、根系活力、电解质渗透率和丙二醛(MDA)、脯氨酸(Pro)、可溶性糖含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响,为利用外源物质减轻盐胁迫伤害提供理论依据。结果显示:(1)NaCl胁迫显著抑制了番茄幼苗的生长、根系活力和SOD、POD、CAT活性,提高了电解质渗透率及MDA、Pro、可溶性糖含量;(2)外源喷施GSH能够诱导NaCl胁迫下番茄幼苗叶片抗氧化酶SOD、POD、CAT活性上调,电解质渗透率及MDA含量下降,Pro和可溶性糖含量恢复至对照水平;(3)外源喷施还原型谷胱甘肽抑制剂(BSO)使NaCl胁迫下番茄幼苗的根系活力以及抗氧化酶SOD、POD、CAT活性下降,脯氨酸含量提高;(4)喷施GSH可诱导BSO和NaCl共处理番茄植株的根系活力、SOD、POD、CAT活性提高,MDA和Pro含量降低。研究表明,外源GSH可通过提高促进盐胁迫下番茄幼苗植株渗透调节能力及清除活性氧的酶促系统的防御能力、降低细胞膜脂过氧化程度、保护膜结构的完整性,从而有效缓解NaCl胁迫对番茄幼苗生长的抑制,提高其耐盐性。

Effect of Exogenous GSH on Tomato Seedlings Growth and Physiological Indexes of Resistance Stress under Salt Stress

Hydroponic experiments were conducted to investigate the effects of exogenous GSH on plant growth and root activity,as well as electrolytic leakage rate,the contents of lipid peroxidation (MDA),proline (Pro) and soluble sugar and the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) in leaves of tomato seedlings under NaCl stress.The result shows that:1)NaCl stress significantly inhibited the growth and root activity of tomato seedlings and decreased the activities of SOD,POD and CAT,and increased electrolyte leakage rate and the contents of MDA,proline (Pro) and soluble sugar in leaves of tomato seedlings.2)The application of exogenous GSH induced the up regulation of POD,SOD and CAT activities,decreased the electrolyte leakage rate and MDA contents,and returned the contents of proline and soluble sugar to control level in leaves of NaCl stressed tomato seedlings.3)The application of exogenous BSO decreased root activity and POD,SOD and CAT activities,and increased proline contents in leaves of tomato seedlings under NaCl stress.4)Spraying GSH increased the root activity and SOD,POD and CAT activities,decreased the contents of MDA and Pro in combined stressed (NaCl and BSO) plants.These results suggested that GSH alleviated salt induced growth inhabitation and enhanced salt tolerance by promoting the osmotic adjustment capacity and the defense ability of antioxidant enzyme system to decrease membrane lipid peroxidation and protect the integrity of membrane structure in tomato seedlings under NaCl stress.