外源硅对锈病菌胁迫下长豇豆幼苗活性氧代谢的影响

 以长豇豆高抗锈病品种‘ZN016’和感病品种‘之豇282’为材料，采用基质栽培，研究了外源硅(Si)处理对锈病菌胁迫下幼苗活性氧代谢的影响。结果表明，与不加Si处理植株相比，外源Si能提高锈病菌胁迫下两品种幼苗叶片POD、CAT和SOD活性，降低O₂^-· 产生速率和H₂O₂、MDA含量，提高感病品种叶片中酚类物质、GSH及AsA含量。在无病原菌侵入时,Si对上述参数影响不一。Si可显著降低感病品种的锈病病情指数，相对防效达31.7%，表明外源Si可通过提高锈菌胁迫下植株体内抗氧化酶活性，降低ROS水平，提高幼苗对锈病的抗性。

Effects of Exogenous Silicon on Reactive Oxygen Species Metabolism of Asparagus Bean Seedlings under Rust Stress

The effects of exogenous silicon (Si) on reactive oxygen species (ROS) metabolism of asparagus bean under Uromyces vignae stress were conducted with two asparagus bean cultivars ‘ZN016’ (highly resistant) and‘Zhijiang 282’ (susceptible) in a substrate culture system. The results indicated that Si promoted the activities of peroxidase (POD), catalase (CAT)and superoxide dismulase (SOD), decreased O₂^-· generation rate and the contents of H₂O₂ and MDA in the leaves of both cultivars, when the plants were inoculated with U. vignae. And the contents of phenolic compound, glutathione (GSH) and ascorbic acid (AsA) in the leaves of inoculated susceptible plants were significantly increased by Si. There were no consistent effects of Si on these parameters when the plants were not infected byU. vignae. Si significantly suppressed rust development in susceptible cultivar ‘Zhijiang 282’, the disease index being 31.7% lower in Si supplied than in Si deprived plants. It indicated that exogenous Si treatment could enhance rust resistance of asparagus bean seedlings through promoting antioxidant enzymes activities and maintaining low ROS levels under rust stress.