外源硫化氢对镉胁迫下黄瓜胚轴和胚根生理生化特性的影响

 以黄瓜（Cucumis sativus L.）种子为试材，研究了外源H₂S预处理对镉胁迫下黄瓜胚轴和胚根生理生化特性的影响。结果表明：用浓度为300、600、900和1 200 μmol · L^-1的H₂S供体NaHS预处理黄瓜种子均能显著缓解镉胁迫对其胚轴和胚根的抑制作用，其中以900 μmol · L^-1 NaHS处理效果最好。NaHS处理显著提高了镉胁迫下黄瓜子叶中淀粉酶的活性及胚轴与胚根中SOD、POD、CAT和APX活性，提高了二苯代苦味酰基自由基（DPPH· ）清除能力和羟基自由基（OH· ）清除能力，从而降低了MDA和H₂O₂含量，而其他钠盐（Na₂S、Na₂SO₄、NaHSO₄、Na₂SO₃、NaHSO₃和NaAc）处理效果甚微，表明NaHS缓解镉胁迫对黄瓜胚轴和胚根生长的抑制作用归因于其释放出的H₂S。

Effects of Exogenous H_2S on the Physiological and Biochemical Characteristics of the Cucumber Hypocotyls and Radicles under Cadmium Stress

The effects of exogenous H₂S on physiological and biochemical characteristics of cucumber hypocotyls and radicles under cadmium stress were studied. The results showed that the inhibited growth of cucumber hypocotyls and radicles by cadmium was alleviated by different concentrations（300 μmol · L^-1，600 μmol · L^-1，900 μmol · L^-1，1 200 μmol · L^-1）of NaHS treatment，especially under the 900 μmol·L^-1 treatment. NaHS treatment significantly increased activities of amylase，SOD，POD，CAT and APX as well as the capacity of α，α-diphenyl-β-picrylhydrazyl radical（DPPH· ）and hydroxyl radical（OH· ）scavenging in both hypocotyls and radicles of cucumber，as the results，the accumulations of MDA and H₂O₂ were decreased. Otherwise，the treatments with other sodium salt including Na2S，Na₂SO₄，NaHSO₄，Na₂SO₃，NaHSO₃ and NaAc had no significant effects on the growth of cucumber hypocotyls and radicles. Based on these results，it could be concluded that the function of NaHS was attributed to H₂S from it.