缺钙玉米叶片的膜脂过氧化伤害

玉米幼苗在缺钙初期叶肉细胞能维持较高的ＳＯＤ活性，膜脂过氧化作用较弱；随缺钙时间延长，ＳＯＤ活性下降，尤其是Ｃｕ，Ｚｎ－ＳＯＤ活性急剧下降，膜脂过氧化作用加强，细胞器破坏．缺钙培养的叶片细胞超微结构的变化首先表现在叶绿体类囊体解体，随后质膜、线粒体膜、核膜和内质网膜等内膜系统紊乱和伤害，而膜系统的伤害可能是缺钙条件下受ＳＯＤ控制的膜脂过氧化作用增强的结果

Lipid peroxidation damage to leaves of Zea mays L. seedlings under calcium deficiency

Corn seedlings were cultured hydroponies until the 4th leaf emerged,then transfered some seedlings to Ca free media every four days until the eighth leaf stage.In the eight leaf corn seedlings,the correlation between lipid peroxidation destruction of membrane system and ultrastructure changes of mesophyll cells was studied. In early stage of Ca deficiency,the mesophyll cells maintained high superoxide dismutase activity and lower lipid peroxidation.With the development of Ca deficiency,the superoxide dismutase activity decreased,especially the Cu,Zn SOD activity,MDA content and membrane permeability increased,cell organelles were destroyed severely and even the whole cell structure was ruined.The ultrastructure damages of mesophyll cells were first observed in chloroplast,followed by the mitochondria, plasmolemma, nuclear membrane and endoplast membrane.The destruction of membrane system under calcium deficiency indicated that lipid peroxidation was enhanced by calcium deficiency.