【摘要】 为探究蚜虫取食刺激诱导榆树虫瘿形成过程中信号化合物的变化和生理响应。本试验以榆瘿蚜(Tetran euraakinire Sasaki)为害的榆树叶片为研究对象,分别测定叶片虫瘿形成不同时期信号化合物的含量及防御酶活性的变化。结果显示:榆瘿蚜为害后,在虫瘿形成的各个时期,茉莉酸(Jasmonic acid,JA)含量显著高于对照,在虫瘿成熟期JA含量为15.087μg/mg,达到峰值,比对照1.570μg/mg增加了近9倍;水杨酸(Salicylic acid,SA)含量无明显变化;脂氧合酶(Lipoxygenase,LOX)与丙二烯氧化物合成酶(Allene oxidesynthase,AOS)活性和JA含量的变化趋势一致;而多酚氧化酶(Polyphenod oxidase,PPO)活性在虫瘿开裂期达到峰值,为对照的3.0倍(P<0.01);而过氧化物酶(Peroxidase,POD)活性随着榆瘿蚜为害逐渐增加,成熟期达到峰值,为对照的3.2倍;苯丙氨酸解氨酶(Phenylalanine ammonialyase,PAL)活性变化和SA含量变化趋势一致,与对照无显著差异。表明榆瘿蚜取食榆树叶片,可诱导榆树叶片JA含量和LOX、AOS等防御酶的活性,并随虫瘿的发育而持续增加,激活体内JA信号转导途径;同时,可显著提高PPO和POD酶的活性,增强其叶片对榆瘿蚜取食的适应能力。更多还原

【Abstract】 In order to explore the physiological response and the changes of signal compounds in the leaves of Ulmu pumilainducted by Tetran euraakinire Sasaki during the forming process of insect galls,the content changes of signal compounds and the activities of defense enzymes were determined respectively in this paper based on the damaged leaves of Ulmus pumilainfested by Tetran euraakinire Sasaki.The results showed that the infestation of Tetran euraakinire Sasaki signally increased jasmonic acid(JA)content in leaves of Ulmu pumila,which was obviously higher than that of the control groups during the formation of insectgalls.In the maturation period of insect galls,the JA content reached the maximum value(15.087μg/mg)and increased ninefold than that of the control plants(1.570μg/mg).The content of salicylic acid(SA)had no obvious changes,and the activities of lipoxygense(LOX)and allene oxidesynthase(AOS)were in accord with the changes of JA content.The activity of polyphenod oxidase(PPO)enzyme reached the peak in dehiscence period,which was 3times higher than that of the control plants(P <0.01).The activity of peroxidase(POD)increased gradually and achieved the peak in maturation period,which was 3.2times higher than that of the control plants.The changes of phenylalanine ammonialyase(PAL)activity showed the same curve as the changes of SA content,and had no significant difference with the control plants.The experiment suggested the infestation of Tetran euraakinire Sasaki could induce the increase of the JA content in leaves of Ulmu pumila and the defense enzymes activity of LOX and AOS with the development of insect galls,and activate JA-signaling transduction pathway,as well as significantly improve PPO and POD activities,enhancing the adaptation of Ulmu pumilaleaves to the infestation of Tetran euraakinire Sasaki.更多还原