摘要
【目的】探究施钾对蓟马为害诱导的苜蓿防御效应的作用。【方法】以紫花苜蓿品种甘农3号为植物试验材料,以牛角花齿蓟马(Odontothrips loti)为研究昆虫,在网室进行盆栽试验。设置不接虫不施钾(K0CK)、不接虫施钾(K2CK)、接虫不施钾(K0)和接虫施钾(K2) 4个处理。于苜蓿5叶1心期,进行接虫处理,K0和K2处理苜蓿每株接入3头蓟马成虫,于接虫后第1、3、5、7和9天,调查接虫苜蓿的受害指数,同时分别摘取各处理苜蓿上部和下部叶片,测定茉莉酸(JA)、水杨酸(SA)含量,以及苯丙氨酸解氨酶(PAL)和脂氧合酶(LOX)活性。【结果】接虫后第1、3、5、7、9天,K2处理苜蓿的受害指数分别较K0显著降低了10.61%、21.40%、23.80%、27.79%和33.06%(P<0.01)。施钾与蓟马为害均能激发JA和SA信号传递途径,除第5天K2处理上部叶的LOX活性低于K0处理上部叶的LOX活性外,其余时期、其余处理苜蓿上部叶和下部叶的LOX和PAL活性以及JA和SA含量大小顺序均为K2>K0>K2CK>K0CK;K2处理苜蓿上部叶的LOX、PAL活性峰值出现时间最早;同一时间同一处理上部叶片的JA和SA含量以及LOX和PAL活性显著高于下部叶片。【结论】蓟马为害可诱导苜蓿叶片提升防御酶LOX和PAL活性,增加茉莉酸和水杨酸的合成积累,且上部叶片(蓟马取食部位)的次生代谢活动启动早且强于下部叶片。施钾加速了蓟马为害诱导的防御酶的活性提升,进而在危害早期提高了茉莉酸和水杨酸含量,提高了苜蓿次生代谢的防御效率,降低了蓟马对苜蓿的危害程度。
【Objectives】To explore the effct of potassium application on induced defence in alfalfa leaves by thrips feeding.【Methods】Medicago sativa Gannong 3 was chosen as experimental material and Odontothrips loti was selected as research insect to carry out pot experiment in net greenhouse.The four treatments were without and with potassium application under insect damage condition(K0,K2),and under no insect damage(K0CK,K2CK),respectively.At the 5-leaf and 1-center period of alfalfa,O.loti adults were immigrated on alfalfa plant with 3 heads per plant in K0 and K2 treatment.At the 1,3,5,7 and 9 days of O.loti feeding,the damage index of alfalfa in K0 and K2 treatment were investigated,the contents of jasmonic acid(JA)and salicylic acid(SA),and the activities of phenylalnine ammonialyase(PAL)and lipoxygenase(LOX)in the upper leaves(top three leaves and the center tip)and lower leaves(the four leaves from the bottom,excluding the leaves of lateral branches)of the four treatments were determined.【Results】Both K and thrips feeding induced the signaling pathways of JA and SA.Compared with K0,K2 decreased the damage index of alfalfa by 10.61%,21.40%,23.80%,27.79%,and 33.06%at 1,3,5,7 and 9 days(P<0.01).The JA and SA contents,and the LOX and PAL activities in upper and lower leaves were all in order of K2>K0>K2CK>K0CK in all the sampling day,except the upper leaf LOX activity in K2 treatment at the 5 day.The peaks of LOX and PAL activity in upper leaves were tested the earliest in K2 treatment.In the same time and treatment,the JA and SA contents and the LOX and PAL activities in upper leaves were higher than those in lower leaves.【Conclusions】O.loti feeding induces the synthesis and increases of the activities of defense enzymes LOX and PAL in alfalfa leaves,promoting the synthesis and accumulation of SA and JA,and the secondary metabolic activity of upper leaves(the feeding site of thrips)reaches peak earlier and stronger than that of the lower leaves.Potassium application speeds up the secondary metabolism in form of earlier and higher LOX and PAL activities and the resulted earlier and higher JA and SA acid contents,thereby further decreases the damage of alfalfa when exposure to O.loti feeding.
作者
胡桂馨
周生英
甘辉林
张航
温雅洁
HU Gui-xin;ZHOU Sheng-ying;GAN Hui-lin;ZHANG Hang;WEN Ya-jie(Paracultural College,Gansu Agricultural University,Lanzhou,Gansu 730070,China;Zhangye City Grassland Workstation,Zhangye,Gansu 734000,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2024年第1期180-189,共10页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(31960350)。
关键词
钾
紫花苜蓿
牛角花齿蓟马
次生代谢
诱导防御
potassium
alfalfa
Odontothrips loti
secondary metabolism
induced defense
