外源硅缓解枸杞NaHCO3盐害的生理反应

Toxic Effects of NaHCO_3 on Lycium dasystemum Alleviated by Exogenous Si

为明确外源硅对木本植物的盐害是否具有缓解作用及其生理机制,研究了外源硅对不同强度NaH-CO3胁迫下枸杞(Lycium dasystemum)叶中超氧阴离子(O2-.)产生速率、丙二醛(MDA)质量摩尔浓度和电解质外渗率,以及保护酶(超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR))活性的影响。结果表明,与对照相比,轻度NaHCO3胁迫下枸杞叶中SOD和POD活性有所增加,而后随胁迫强度的增加,SOD和POD活性逐渐下降,CAT和GR活性则随胁迫强度的增加逐渐降低,同时NaHCO3胁迫导致了O2-.产生速率、MDA质量摩尔浓度和电解质外渗率的增加。外施硅明显提高了各胁迫处理下枸杞叶中SOD、POD、CAT和GR活性,并降低了叶中O2-.产生速率、MDA质量摩尔浓度和电解质外渗率。外源硅增强了枸杞对NaHCO3胁迫的抗性,并在一定程度上缓解了NaHCO3对枸杞的毒害。

To discuss the alleviation of soluble Si to woody plants, this study focuses on the changes in generation rate of O2, MDA content, electrolyte leakage and activities of protective enzymes （ SOD, POD, CAT and GR） in leaves of Lycium dasystemum under different intensities of NaHCO3 stress with exogenous Si. Results showed that, under single NaHCO3 stress, mild stress led to a slight increase in the activities of SOD and POD in the leaves of L. dasystemum compared to the control, and then the activities of SOD and POD decreased gradually. With increasing stress intensity, the activities of CAT and GR decreased gradually, while the generation rate of O2, MDA content and electrolyte leakage increased gradually. The activities of these protective enzymes （SOD, POD, CAT and GR） markedly increased with the addition of sprayed soluble Si under different stress intensities, but the generation rate of O2-, MDA content and electrolyte leakage decreased. Exogenous Si could enhance the tolerance of L. dasystemum to NaHCO3 exposure and mitigate the toxic effects of NaHCO3 on L. dasystemum to a certain extent.