Influence of an elevated CO2 level on life history parameters and hormone pathway or vitellogenin metabolism of the brown planthopper.zip

The growth, development and reproduction of herbivorous insects could be altered due to changes in quality and quantity of their host plants under elevated CO₂. The brown planthopper, <i>Nilaparvata lugens</i>, is one of the most serious and destructive economic pests in rice growing areas in Asia. In this study, we investigated the effect of elevated CO₂ on the growth, development and reproduction of <i>N. lugens</i> and, in particular, on the hormonal regulation of the transcription factors in <i>N. lugens</i>. The results indicated that compared with ambient CO₂, elevated CO₂ significantly shortened the duration of egg and nymph, longevity of female adults and total adults, and significantly decreased the weight of adults; besides, elevated CO₂ significantly improved the fecundity of female adults, egg hatching rata and the transcription levels of <i>Vg</i>. The relative expression levels of <i>JHMAT</i> and <i>FAMeT</i> regulated synthesis of JH were first down-regulated and then up-regulated with development of the 5th instar nymph of <i>N. lugens</i> under elevated CO₂. In addition, the relative expression level of <i>cyp314a1</i> played important role in synthesis of ecdysone was up-regulated in the 5th instar nymph of <i>N. lugens</i> under elevated CO₂. We have demonstrated that elevated CO₂ could accelerate the development and improve reproduction of <i>N. lugens</i>, which is related to the transcription levels of JH, MH and Vg.

大气CO₂浓度升高会通过改变寄主植物的质量与数量，进而影响植食性昆虫的生长、发育与繁殖。褐飞虱（Nilaparvata lugens）是亚洲水稻种植区最具危害性的毁灭性经济害虫之一。本研究探究了大气CO₂浓度升高对褐飞虱生长、发育及繁殖的影响，重点聚焦于其体内转录因子的激素调控机制。结果显示，相较于环境CO₂浓度组，高CO₂浓度组显著缩短了褐飞虱的卵期与若虫期时长，降低了雌成虫及整体成虫的寿命，同时显著降低了成虫体重；此外，高CO₂浓度显著提升了雌成虫的繁殖力、卵孵化率以及卵黄原蛋白（Vitellogenin, Vg）的转录水平。在高CO₂浓度环境下，调控保幼激素（Juvenile Hormone, JH）合成的JHMAT与FAMeT的相对表达量，随褐飞虱5龄若虫的发育进程先下调后上调。此外，在高CO₂浓度环境下的褐飞虱5龄若虫中，参与蜕皮激素（Moulting Hormone, MH）合成的cyp314a1的相对表达量显著上调。本研究证实，大气CO₂浓度升高可加速褐飞虱的发育进程并提升其繁殖能力，该效应与保幼激素、蜕皮激素以及卵黄原蛋白的转录水平密切相关。