不同诱导因子对膜脂过氧化与对超微结构影响的关系

为了阐明诱导因子诱导系统获得性抗性机制,研究了百草枯PQ,钛铁试剂Tiron和稻白叶枯菌弱毒株XOO75-1等诱导因子对稻白叶枯病的系统获得抗性、诱导叶活性氧代谢及挑战接种叶超微结构的影响.结果表明,PQ和XOO75-1可诱导系统获得抗性.XOO75-1使处理稻叶SOD和CAT活性降低,使POD活性、O2i产生速率及MDA含量升高;PQ使SOD,CAT,POD活性、O2i产生速率及MDA含量升高;两者均使处理稻叶膜脂IUFA降低,饱和脂肪酸相对含量升高.PQ和XOO75-1使挑战接种叶病斑附近组织结构受保护,比未处理叶的细胞结构损伤小,较接近正常叶,细胞内结构以叶绿体变化最为显著.Tiron处理使PQ和XOO75-1诱导的系统获得抗性减弱,诱导局部的活性氧变化减小以及病斑附近的结构改变更显著.证明O2i在XOO系统获得抗性中起重要作用.

Effects of different induction factors on relation between peroxidation in membrane lipid and ultrastructure

This paper is an attempt to study the effects of three induction factors,paraqat (PQ) and Tiron and Xanthomonas oryzae pv. oryzae (XOO) 75-1(avirulent),on induced systemic acquired resistance to XOO,metabolism of active oxygen species (AOS) in treated leaves and ultrastructure in leaves challenged by XOO 76-25(virulent).The results showed that systemic resistance was induced by PQ and XOO 75-1;activities of SOD and CAT decreased and O 2i -generation rate and MDA content increased in leaves treated by XOO 75-1;activities of SOD and POD and CAT, O 2i -generation rate and MDA content increased in leaves treated by PQ;IUFA decreased and relative content of saturated fatty acid increased in membrane lipid;the cell structure near lesion on challenged leaves of seedling treated PQ and XOO 75-1 were protected and the changes of chloroplast were most obvious among all structure in cell near lesion;Tiron made systemic resistance were weakened,changes of AOS in treated leaves decreased,and changes of ultrastructure near lesion were more obvious in seedling induced by both factors. These results prove that O2i plays an important role on induced systemic acquired resistance to XOO.