亚硫酸对紫丁香、皂角叶片膜质过氧化的影响及其磷酸缓冲液的防护作用

EFFECT OF SULPHUROUS ACID ON MEMBRANE LIPIDPEROXIDATION IN LEAVES OF SYRINGA VULGARISGLEDITSIA JAPONICA AND PROFECTIVE FUNCTION OFPHOSPHATE BUFFER

以紫丁香、皂角为材料研究亚硫酸对叶片膜质过氧化的影响，结果表明，低浓度（５ｍｍｏｌ／Ｌ）的ＮａＨＳＯ３，使叶片的ＳＯＤ活性上升，ＭＤＡ含量下降。高于５ｍｍｏｌ／Ｌ的ＮａＨＳＯ３使ＳＯＤ活性下降，ＭＤＡ含量升高；且ＮａＨＳＯ３浓度越大，ＳＯＤ、ＭＤＡ变化幅度越大，ＮａＨＳＯ３处理也使得叶绿素———蛋白质结合度下降。植物材料经磷酸缓冲液喷洒后，膜质过氧化程度降低，表现为在各种浓度ＮａＨＳＯ３处理中，叶片的ＳＯＤ活性、叶绿素———蛋白质结合度均高于未喷磷液者；而ＭＤＡ含量均低于未喷者。表明磷液对亚硫酸伤害具有防护作用，防护效果与植物材料、亚硫酸浓度和生理指标有关。

When leaves of Syringa vulgaris, Gleditsia japonica were treated with lower concentration sulphurous acid(5mmol/L),the acativities of superoxide dismutase(SOD)in leaves increased, while the levels of malondialdehyde(MDA)were reduced. After a higher concentration(>5mmol/L)sulphurous acid treatment, the SOD activities of leaves were found be reduced, while MDA contents were increased. Every concentration sulphurous acid could decrease the degree of chlorophyllprotein binding. After the plants were sprayed with phosphate buffer, they had an obvious protective function to the harm caused by sulphurous acid. The phosphate buffer could increase SOD activity, decrease MDA content and increase the degree of chlorophyllprotein binding. The protective effect of phosphate buffer was different with plant species, sulphurous acid concentration, and physiological index.