Effects of exogenous silicon supply on the activity of antioxidant enzymes of tomato leaves infected by Ralstonia solanacearum

【Objective】The objective of this study was to investigate the physiological mechanism of silicon-induced resistance of tomato plant to bacterial wilt.【Method】Pot experiments with soil and hydroponic cultivation were conducted to study the effects of silicon supply on the disease index of bacterial wilt and antioxidant enzymes of tomato leaves.【Result and conclusion】The results showed that exogenous Si treatment reduced the disease index of bacterial wilt by 29.1%-93.0% respectively in soil cultivation experiment and 6.3%-100% respectively in hydroponic experiment compared with no-Si-treatment. Compared with the no-silicon treatment, Si application increased POD and CAT activity of tomato leaves by 43.17% and 23.17% in soil cultivation experiment. Si amendments significantly increased POD, CAT and PAL activity of tomato leaves by 122%, 337% and 31% respectively in hydroponic experiments. In conclusion, Si supply has an important role in suppressing bacterial wilt caused by Ralstonia solanacearum. The pathogen resistance mediated by Si is associated with the activation of defense-related enzyme activities in leaves.