外源硫化氢缓解水稻盐胁迫的作用机理

Functional Mechanism of Exogenous H_2S to Relieve Salt Stress in Rice

为探明外源H_2S缓解水稻盐胁迫的作用机理,以水稻日本晴为材料,在水培条件下,研究H_2S对NaCl胁迫下5叶期水稻幼苗生长与活性氧(ROS)代谢和抗氧化酶系统的影响。结果表明:100mmol/L NaCl处理严重抑制水稻幼苗的生长,诱导ROS的产生,造成氧化损伤;盐胁迫下添加抗氧化酶抑制剂(二乙基二硫代氨基甲酸钠DDC或3-氨基-1,2,4-三唑AT),活性氧(ROS)得不到及时有效分解而高水平累积,加剧了氧化胁迫对植物的伤害;在盐胁迫条件下添加100μmol/L NaHS(外源H_2S供体)处理,能显著增加叶片内H_2S水平,加快活性氧的清除,从而减轻盐胁迫下的膜脂过氧化程度,促进植物生长。H_2S具有抗氧化作用,外施H_2S可提高植物耐盐性。

The effects of exogenous H2S on growth, reactive oxygen species（ROS） and antioxidase system of Oryza sativa L. var Nipponb seedlings at five-leave stage were studied under hydroponic culture and salt stress to verify the function mechanism of exogenous H2 S to relieve salt stress in rice. Results： 100 mmol/L NaCl inhibits growth of rice seedlings very significantly because of oxidative damage caused by induced reactive oxygen species（ROS）. Application of DDC and AT （ antioxidant enzymes inhibitors） inhibits scavenging of reactive oxygen species （ROS）under salt stress, which results in high ROS accumulation in leaves and intensifies seedling damage from oxidative stress. Application of 100μmol/L Naris （exogenous H2S） can increase H2S level in leaves of rice seedlings under salt stress significantly and speed up scavenging of reactive oxygen species （ROS）, which can decrease membrane lipid peroxidation degree and promote growth of rice seedlings. In conclusion, Applying exogenous H2 S with an antioxygenation can improve plant salt tolerance.