外源硅对锈菌诱导下豇豆叶片不同细胞器中抗氧化特征的影响

Effects of exogenous silicon on antioxidant capacities in sub-cellular fractions of asparagus bean seedlings under rust stress

以长豇豆高抗锈病材料‘ZN016’和高感品种‘之豇282’为材料,通过基质栽培,研究锈菌胁迫下外源硅对长豇豆叶片细胞质、线粒体和叶绿体抗氧化酶活性与抗氧化物质含量的影响。结果表明:锈菌胁迫下,外源硅可显著提高豇豆细胞质、线粒体和叶绿体中过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)和苯丙氨酸解氨酶(PAL)的活性以及线粒体内的超氧化物歧化酶(SOD)活性;同时显著提高细胞质内的多酚含量和感病品种线粒体中抗坏血酸(AsA)的含量;外源硅可显著降低感病品种细胞质和叶绿体中的丙二醛(MDA)含量。推测锈菌胁迫下外源硅可能通过提高豇豆叶片细胞质和叶绿体的抗氧化能力,从而避免活性氧对细胞质膜和叶绿体膜系统的伤害,维持其正常的生理功能。

The effects of exogenous silicon （Si） on antioxidant ability of two asparagus bean cultivars, ‘ZN016’ （highly resistant） and ‘Zhijiang 282’ （susceptible）, were investigated at sub-cellular level （cytoplasm, chloroplast and mitochondria） under rust （Uromyces vignae） stress by suhstrate culture. The results indicate that application of exogenous Si significantly increased the activities of peroxidase （POD）, ascorbate peroxidase （APX）, eatalase （CAT）, and phenylalanine ammonia-lyase （PAL） in three sub-cellular fractions, and superoxide dismutase （SOD） activity of mitochondria for both eultivars, and the ascorbate acid （AsA） content in mitoehondria of susceptible cultivar under rust stress. Consequently, the content of malonyldialdehyde （MDA） in cytoplasm and chloroplast of susceptible cultivar was significantly reduced by exogenous Si application under rust stress. These results above indicated that enhanced rust resistance of asparagus bean by exogenous Si application could increase their antioxidant capacities, which can quench reactive oxygen species more efficiently and maintain the integrity and biological function of cytoplasmic membrane and chloroplast membrane.