| As abundant distribution and used safely, the role of silicon in inducing resistance for postharvest disease of fruits and vegetables is regarded more and more important. In this paper, sodium silicate at 100mM was used as a postharvest treatment of induction resistance on muskmelon (Cucumis melo L. cv. Yindi) to analysis the mechanism on controlling disease, including reactive oxygen and its antioxidant protection systems, some key enzymes and products in phenylpropanoid pathway. The results indicated as follow:1. Si treatment increased the content hydroxyl radical (·OH) and superoxide(O2-). The content of·OH and O2- could be raised by challenged with T. roseum inoculation. Both malondialdehyde(MDA) and hydrogen peroxide(H2O2) were also accumulated with Si treatment and challenged inoculation. Si treatment maintained membrane integrity intreated fruit inoculated with T. roseum.2. Si treatment and challenge inoculation increased significantly the activity of superoxide dismutase (SOD), glutathion reductase (GR), peroxidase (POD) and polyphenoloxidase (PPO), decreased the activity of catalase (CAT) and ascorbic peroxidase (APX); however, the activity of CAT and APX showed higher than the control. Si treatment and challenge inoculation also enhanced the content of ascorbic acid (AsA) and glutathione (GSH).3. Si treatment and challenge inoculation enhanced significantly phenylalanine ammonia-lyase (PAL) activity. The activity of 4-coumarate:CoA ligase(4CL) was not effected by Si treatment; however, the activity was primed after challenge inoculation.The activity of cinnamyl alcohol dehydrogenase(CAD) could be enhanced by Si treatment. Challenge inoculation improved the activity in the control, but failed to effect the treated fruit.4. Si treatment and challenge inoculation accumulated significantly the content of total phenolic, flavanoid and lignin in treated fruit. The lesion diameter of treated fruit inoculated with T. roseum was also reduced. |
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