桃蚜取食行为对大气CO_2浓度升高的响应

Feeding behavior of the peach aphid under elevated CO_2 levels

【目的】近年来随着人类活动的增加,温室气体尤其是大气CO_2浓度升高造成的虫害爆发已成为国际上关注的焦点,因此,研究拟南芥Arabidopsis thaliana上桃蚜取食行为的变化对大气CO_2浓度升高的响应意义重大。【方法】本研究以拟南芥和绿色桃蚜Myzus persicae为研究对象,利用野生型拟南芥Col-0,茉莉酸途径信号传导缺失突变体(jar1)、水杨酸途径信号传导缺失突变体(npr1)、乙烯途径信号传导缺失突变体(ein2-5)为材料,以大气CO_2浓度升高为影响因子,利用刺吸式电位仪(EPG)记录了桃蚜在不同处理的拟南芥上的取食波形。【结果】研究结果发现:CO_2浓度升高缩短了Col-0和jar1植株上蚜虫首次刺探时间和首次到达韧皮部的时间,却延长了npr1和ein2-5上蚜虫首次到达韧皮部的时间,降低了jar1植株上蚜虫总的刺探时间且增加了其总的取食韧皮部时间,但没有改变其它基因型植株上蚜虫总的刺探和取食时间;同时增加了野生型植株上蚜虫的刺探频率,却没有影响其它基因型植株上的刺探频率。【结论】CO_2浓度升高降低了野生型植株和jar1植株抗性,有利于蚜虫到达韧皮部;却增加了npr1和ein2-5上的植物抗性,从而不利于蚜虫到达韧皮部。

[Objectives] The global atmospheric concentration of carbon dioxide（CO_2） has been increasing quickly, resulting in outbreaks of insect pests that have caught the world＇s attention. Studies of the feeding behavior of the peach aphid, Myzus persicae, on Arabidopsis under elevated atmospheric CO_2 levels are, therefore, timely. [Methods] Electrical penetration graph（EPG） technology was used to examine the feeding behavior of peach aphids on the wild type and three mutant varieties（jar1、npr1、ein2-5） of Arabidopsis thaliana, with a particular focus on the role of jasmonic acid, salicylic acid and ethylene signaling pathways under elevated CO_2 levels. [Results] Elevated CO_2 delayed the first appearance of C, E1 and E2 aphids on Col-0 and jar1 plants, but advanced the first appearance of C, E1 and E2 aphids on npr1 and ein2-5 plants. Furthermore, elevated CO_2 decreased the duration of C aphid infestation, and increased the duration of E2 aphid infestation on jar1 plants, but did not affect these parameters on the other varieties. In addition, elevated CO_2 increased the total frequency of C and pd aphids on Col-0 but not on the other varieties. [Conclusion] Changes in aphid feeding behavior under elevated CO_2 conditions suggest that elevated CO_2 decreased the resistance of the Col-0 and jar1 varieties to aphids, but increased the resistance of npr1 and ein2-5 plants. These results indicate that elevated CO_2 can modify aphid feeding behavior by altering plant＇s defensive phytohormone mediated resistance.