摘要
为探究外源茉莉酸甲酯(MeJA)对苜蓿抗蓟马性的影响,本研究以草原4号紫花苜蓿为材料,分别外源喷施0.01 mmol/L MeJA、0.10 mmol/L MeJA、1.00 mmol/L MeJA、1.00 mmol/L茉莉酸合成抑制剂(DIECA),连续喷施3 d后接种牛角花齿蓟马(Odontothrips loti),测定蓟马接种0、7、14 d后的虫口数.在此基础上,分析不同处理下苜蓿叶片相关生理指标(氧化防御酶、次生代谢物、可溶性蛋白和可溶性糖含量)的变化,探究MeJA影响苜蓿抗蓟马性的生理机制.结果表明:与对照(喷施蒸馏水,CK)相比,低浓度的MeJA(0.01 mmol/L和0.10 mmol/L)可显著降低蓟马危害7 d和14 d后的叶片虫口数(P<0.05),1.00 mmol/L MeJA处理显著降低蓟马危害14 d后的虫口数,DIECA处理对蓟马虫口数没有显著影响.外源0.10 mmol/L MeJA处理显著增强了未接种蓟马苜蓿叶片过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、脂氧合酶(LOX)的活性以及单宁和类黄酮含量(P<0.05).接种蓟马7 d后,外源MeJA处理的苜蓿叶片PPO和LOX活性显著高于CK,而SOD和PAL活性及类黄酮含量显著低于CK(P<0.05);外源DIECA处理显著增强了SOD的活性和可溶性蛋白含量(P<0.05),而POD和PPO活性以及单宁和类黄酮含量均显著低于CK(P<0.05).接种蓟马14 d后,外源MeJA处理叶片的POD、谷胱甘肽过氧化物酶(GPX)、LOX活性和单宁含量均显著高于CK,类黄酮、可溶性糖和可溶性蛋白含量均显著低于CK(P<0.05);外源DIECA处理的谷胱甘肽还原酶(GR)和PAL活性以及类黄酮、总酚、可溶性蛋白、可溶性糖含量均显著低于CK(P<0.05).综合以上结果表明,外源MeJA能通过调节苜蓿生理防御反应来增强其抗蓟马性.
Abstract
In order to investigate the effect of exogenous methyl jasmonate(MeJA)on the thrips resis-tance of alfalfa,Medicago sativa cv.Caoyuan No.4 was continuous sprayed with distilled water(CK),0.01 mmol/L,0.10 mmol/L,1.00 mmol/L MeJA and 1.00 mmol/L jasmonic acid synthesis inhibitor(DIECA)for 3 days,respectively,and then thrips(Odontothrips loti)was inoculated.The number of thrips was measured after 0 d(no inoculation),7 d and 14 d inoculation,and the changes of relevant physi-ological characteristics(activities of oxidative defense enzymes,contents of secondary metabolites,soluble protein and soluble sugar)of alfalfa leaves under different treatments were performed.The results showed that compared with the CK group,low concentrations of MeJA(0.01 mmol/L and 0.10 mmol/L)signifi-cantly reduced the thrips density on the 7th and 14th day(P<0.05),while treatment with 1.00 mmol/L significantly reduced the thrips density after 14 days thrips feeding,while the DIECA treatment had no sig-nificant effect on the thrips density.Exogenous 0.10 mmol/L MeJA treatment significantly enhanced the activities of peroxidase(POD),phenylalanine ammoniase(PAL),polyphenol oxidase(PPO),lipoxygen-ase(LOX),as well as the contents of tannins and flavonoids in alfalfa leaves without inoculation with thrips(P<0.05).After 7 days of inoculation with thrips,the PPO and LOX activities of alfalfa leaves treated with exogenous MeJA were significantly higher than those of CK,while the SOD and PAL activi-ties and flavonoids content were significantly lower than those of CK(P<0.05).Exogenous DIECA treat-ment significantly enhanced the activity of SOD and soluble protein content(P<0.05),while the activity of POD and PPO,as well as the content of tannins and flavonoids,were significantly lower than those of CK(P<0.05).After 14 days of inoculation with thrips,the activities of POD,glutathione peroxidase(GPX),LOX and the content of tannin in leaves treated with exogenous MeJA were significantly higher than those in CK,while the contents of flavonoids,soluble sugar and soluble protein were significantly lower than CK(P<0.05).In addition,the activities of glutathione reductase(GR)and PAL,as well as the contents of flavonoids,total phenols,soluble protein and soluble sugar,were significantly lower in the exogenous DIECA treatment than those in CK treatment(P<0.05).These results indicated that exog-enous MeJA could enhance the resistance of alfalfa to thrips by regulating its physiological defense response.
基金项目
内蒙古自治区高等学校青年科技英才支持计划(NJYT23009)
内蒙古自治区自然科学基金面上基金(2021SHZR0721)
内蒙古自治区直属高校基本科研业务费专项(BR22-11-12)
高等教育改革发展研究生科研创新资助项目(S20231109Z)
NETL
NSTL
万方数据