牛角花齿蓟马为害对紫花苜蓿AsA、GSH含量及相关代谢酶活性的影响

The effect of Odontothrips loti damage on AsA,GSH content and metabolic enzyme activities in alfalfa plants

为了明确非酶抗氧化物质抗坏血酸(AsA)、还原型谷胱甘肽(GSH)及相关代谢酶抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)在紫花苜蓿(Medicago sativa L.)对牛角花齿蓟马Odontothrips loti Haliday为害的抗性中的作用,测定了不同牛角花齿蓟马虫口密度下抗、感蓟马苜蓿无性系R-1、I-1的AsA、GSH含量及APX、GR活性的变化。结果表明:受牛角花齿蓟马为害后,R-1无性系在低虫口密度(1、3头/枝条)下,AsA、GSH含量和GR活性均上升,在高虫口密度(5、7头/枝条)下,AsA含量和GR活性先升高后下降,GSH含量上升后保持稳定;I-1无性系的AsA、GSH含量先升高后下降,GR活性在为害后期呈上升趋势;R-1、I-1无性系的APX活性均先上升后下降,但R-1无性系APX活性的上升速率及下降速率小于I-1无性系。说明AsA、GSH含量及APX、GR活性的升高可能是紫花苜蓿对牛角花齿蓟马诱导抗性的一种表现,但I-1无性系对蓟马为害的应激反应滞后于R-1无性系。在牛角花齿蓟马为害后期,R-1无性系体内的AsA、GSH含量及APX、GR活性仍处于较高水平,也说明了R-1无性系对牛角花齿蓟马为害的抗性较I-1无性系强。

The function of non-enzymatic antioxidant ascorbic acid （AsA） , reduced glutathione （GSH） and metabolic enzymes ascorbate peroxidase （APX） and glutathione reductase （GR） on the resistance of alfalfa to thrip damage were investigated. AsA and GSH contents, and the activities of APX and GR in resistant and susceptible alfalfa clones, R-1 and I-1, grown under different thrip densities, were measured. For R-1 treatments, AsA, GSH contents and GR activity increased under low thrip densities （1, 3 per branch） , while under high densities （5,7 per branch） , AsA content and GR activity first increased then decreased, while GSH content initially increased then remained stable. For I-1 treatments, AsA and GSH contents first increased then decreased, and GR activity displayed a tendency to increase during the late damage stage. APX activities for both clones increased at first and then decreased, but the amplitude of the fluctuation for R-1 was less than that for I-1, indicating that AsA and GSH content, and APX and GR activity, might be a form of resistance induced in alfalfa by thrip damage, with the response of I-1 to such damage lagging behind that of R-1. During the later damage stage, AsA and GSH content and APX and GR activity in the R-1 clones remained at a high level,indicating that R-1 plants had a greater capacity than I-1 to resist thrip damage.