Effect of Aphid Stress on the Antioxidant Index and Active Oxygen Metabolism in Leaves of Different Resistant Maize Varieties

PurposeIn order to determine the effect of maize aphid pricking stress on the contents of AsA and GSH, APX activity and active oxygen metabolism in the leaves of resistant and susceptible maize varieties.

MethodThe contents of AsA,GSH,O₂⁻, H₂O₂ and OH⁻ and APX activity in the leaves of susceptible maize aphid cultivar Liyu16 and resistant maize aphid cultivar Zhengdan958 were determined at 24, 48 and 96 hours under maize aphid pricking stress.

ResultThe content of AsA in the leaves of Liyu16 maize seedlings increased significantly at 24, 48 and 96 h, while that in Zhengdan958 maize seedlings at 48 and 96 h was significantly higher than that in the control (P<0.05), and the contents of GSH in leaves of Zhengdan958 seedlings were significantly lower than that of the control at 24 h (P<0.05). The contents of GSH in the leaves of Liyu16 and Zhengdan958 seedlings were significantly higher than that of the control at 48 and 96 h of pricking (P<0.05); APX activities in the leaves of Liyu16 and Zhengdan958 varieties decreased gradually with the prolongation of aphid pricking time; the contents of H₂O₂ in the leaves of Liyu16 varieties were significantly higher at 24, 48 and 96 h under maize aphid pricking stress (P<0.05), but at 24 h under maize aphid pricking stress, the contents of H₂O₂ in the leaves of Zhengdan958 varieties were significantly higher than that of the control (P<0.05). The contents of OH⁻ in the leaves of Liyu16 seedlings were significantly higher than those of the control at 48 h and 96 h of pricking (P<0.05), while the content of OH⁻ in leaves of Zhengdan958 were significantly higher at 24, 48 and 96 h under maize aphid pricking stress(P<0.05). The contents of O₂⁻ in the leaves of Zhengdan958 seedlings were significantly higher than those of the control at 48 h and 96 h of pricking (P<0.05), while the content of O₂⁻ in the leaves of Liyu16 were significantly higher at 24, 48 and 96 h of maize aphid pricking stress (P<0.05).

ConclusionThe above results indicated that the contents of AsA, GSH, APX and the metabolism of reactive oxygen species in the leaves of aphid-resistant and susceptible cultivars changed correspondingly when they were susceptible to maize aphid pricking stress, but the effects on reactive oxygen species of susceptible cultivar Liyu16 were greater than those on resistant cultivar Zhengdan958.