烟粉虱体内几种抗性酶对寄主转换的响应

将烟粉虱分别从嗜性较强的番茄植株上转移到嗜性相对较弱的国抗22(GK22)棉花、泗棉3号(S3)棉花和辣椒植株上,以及从嗜性较弱的辣椒植株上转移到嗜性相对较强的番茄、GK22棉花和S3棉花植株上,观察寄主转移后F1代、F2代和F3代烟粉虱体内α-NA羧酸酯酶、谷胱甘肽-s-转移酶和多功能氧化酶活性的变化,再将F4代烟粉虱转移到原寄主,同样观察这3种抗性酶的变化。结果表明,不同嗜性的寄主上烟粉虱体内3种酶活性的强弱与烟粉虱对这种寄主的嗜性相关,在嗜性较强的寄主上,3种酶的活性相对较低。烟粉虱从嗜性较强的寄主转移到嗜性相对较弱的寄主后,成虫体内α-NA羧酸酯酶、谷胱甘肽-s-转移酶和多功能氧化酶的活性显著上升,从嗜性较弱的寄主转移到嗜性较强的寄主后,羧酸酯酶和谷胱甘肽-s-转移酶的活性下降。在寄主转移过程中,烟粉虱体内的α-NA羧酸酯酶和谷胱甘肽-s-转移酶活性一般在F2代基本稳定,而多功能氧化酶在F1代就能迅速稳定。烟粉虱从过渡寄主再转移到原寄主的过程中,其3种酶的变化规律与上述寄主基本一致。结果提示,在烟粉虱寄主转换过程中,多功能氧化酶具有快速响应特性和较强的稳定性,而α-NA羧酸酯酶和谷胱甘肽-s-转移酶活性的变化与烟粉虱对寄主的适应度变化基本一致。

Responses of detoxification enzymes in Bemisia tabaci (Gennadius) to host shift

The responses of the enzyme activity of carboxylesterase (CarE), glutathione\|s\|transferase (GST) and multifunction oxidase (MFO) in Bemisia tabaci to host shift were investigated in this study. Host shifts include from tomato plants (a high preference crop) to GK 22 cotton, Simian 3 cotton and capsicum plants (3 relatively low preference crops) and from capsicum plants (a low preference crop) to GK22 cotton, Simian 3 cotton and tomato plants (3 relatively high preference crops), and also include that the F4 generation of B. tabaci on the new hosts was transferred back to the original hosts. Our results suggested that the enzyme activity of CarE, GST and MFO in B. tabaci was related to the host preference. The activity of the three detoxification enzymes in B. tabaci on the high preference host plants was relatively low. After being transferred from the high preference hosts to the low preference hosts, the enzyme activity of CarE, GST and MFO in B. tabaci was significantly increased. After being transferred from the low preference hosts to the high preference hosts, the enzyme activity of CarE, GST and MFO in B. tabaci was significantly reduced. During host shift, the activity of CarE and GST in B. tabaci was usually stabilized in the F2 generation, while the activity of MFO could be rapidly stabilized in the F1 generation. During the shift from the transitional hosts to the original host plants, similar trends were observed in the activity of CarE, GST and MFO. In addition, during the host shift, the activity of MFO in B. tabaci responded and was stabilized rapidly, while the changes of CarE and GST corresponded to the adaptability of host change.