硅对燕麦抗秆锈病及抗氧化特性的影响OA

To explore the effects of silicon(Si)on the physiological characteristics of oat leaves infected by Puccinia graminis f.sp.avenae and clarify the physiological mechanism of silicon-induced resistance to stem rust,a pot experiment was conducted using ʻBayou 1ʼ,an oat cultivar highly susceptible to stem rust,as the experimental material.Four treatments were established:CK(no silicon,no stem rust pathogen inoculation),+Si-P(silicon application,no stem rust pathogen inoculation),-Si+P(no silicon,stem rust pathogen inoculation),and+Si+P(silicon application,stem rust pathogen inoculation).This study investigated the effects of 1.5 mmol/L silicon application on the disease progression,reactive oxygen species content,and antioxidant enzyme activities of oat leaves after stem rust pathogen infection.The results showed that silicon application effectively delayed the disease development process of oat stem rust,and significantly alleviated disease symptoms.Stem rust pathogen infection led to a rapid increase in O2–.and hydrogen peroxide content in leaves.Simultaneously,the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT),malondialdehyde(MDA)content,and relative electrical conductivity of leaves increased rapidly,while ascorbate peroxidase(APX)activity decreased rapidly.Within seven days after stem rust pathogen inoculation,silicon application reduced the reactive oxygen species content in leaves,while increasing the activities of SOD,POD,and CAT,and decreasing APX activity and MDA content.Furthermore,silicon application reduced the relative electrical conductivity of leaves within 11 days after inoculation.Silicon application enhanced the antioxidant defense ability of oat leaves,reduced the degree of membrane lipid peroxidation,and enhanced oat resistance to stem rust.