Growth, development and fecundity of brwon planthopper and the regulation mechanism in response to elevated CO2.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> (Stål), 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 levels 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.