丛枝菌根真菌摩西管柄囊霉侵染增强番茄对机械损伤的响应

Colonization with arbuscular mycorrhizal fungus Funneliformis mosseae enhanced the responses of tomato plants to mechanical wounding

植食性昆虫取食会给植物造成机械损伤并激活植物的防御反应,而与有益微生物共生是否可以增强植物对机械损伤的响应对植物抗虫有重要意义.本研究在番茄根系被丛枝菌根真菌摩西管柄囊霉侵染后,研究机械损伤对番茄防御反应的影响.结果表明:预先接种菌根真菌的番茄叶片受到机械损伤处理(FD)后,叶片苯丙氨酸解氨酶(PAL)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)和过氧化氢酶(CAT)活性,以及叶片和根系苯丙氨酸解氨酶基因(PAL)和β-1,3-葡聚糖酶基因(PR2)的转录水平均显著高于只进行机械损伤的处理(D)、只接种摩西管柄囊霉的处理(F),以及既未接种菌根菌也未进行机械损伤的健康番茄植株(CK).虽然D和F处理也可诱导部分酶活性及基因转录水平升高,但FD处理诱导的防御反应更迅速和强烈.表明丛枝菌根真菌侵染可以警备(prime)番茄对机械损伤做出更快速和强烈的响应.

Insect herbivore feeding causes mechanical damage to plants,which can activate plant defense responses. Whether symbiosis with beneficial microorganisms can enhance the responses of plants to mechanical damage is of importance for plant anti-herbivore resistance. In this study,defense responses of tomato（Lycopersicon esculentum） plants to mechanical wounding was investigated after the tomato roots being infected by arbuscular mycorrhizal fungus（AMF） Funneliformis mosseae.The results showed that in response to leaf mechanical wounding,the activities of phenylalanine ammonia-lyase（PAL）,superoxide dismutase（SOD）,peroxidase（POD）,polyphenol oxidase（PPO） and catalase（CAT） in the leaves of tomato pre-inoculated with AMF（FD）,as well as transcript levels of genes encoding phenylalanine ammonia lyase（PAL） and β-1,3-glucanase（PR2） in the leaves and roots were significantly higher in relative to sole mechanical wounding（D）,sole mycorrhizal inoculation（F）,and control without mechanical wounding and mycorrhizal inoculation（CK）. Although the activities of protective enzyme and transcript levels of the two defense-related genes were induced in the plants of sole mechanical wounding（D） and sole mycorrhizal inoculation（F）,the induction was faster and stronger in the plants with leaf mechanical wounding and mycorrhizal pre-inoculation（FD）. Our findings indicated that arbuscular mycorrhizal colonization could prime quicker and stronger defense responses of tomato plants to mechanical damage.