Abstract: 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.

Key words: Asparagus bean, Rust, Silicon, Reactive oxygen species, Antioxidant enzyme