Study On The Respose And Digital Gene Expression Profiling Of Nilaparvata Lugens To Elevated CO₂ Concentrarions

Current atmospheric carbon dioxide（CO₂） level is expected to increase from about 380μL/L to 750μL/L by the end of the 21 st century, primarily as a result of anthropogenic activities such as the burning of fossil fuels. Elevated CO₂ can improve the biomass of plant, change the secondary compounds and nutritional quality of rice, which in turn affects the growth and development, physiology and biochemistry of brown planthopper（Nilaparvata lugens（St?l））. In this study, we set three CO₂ levels by 390μL/L, 550μL/L and 750 μL/L. We had systematically examined the impacts of three CO₂ treatments on the growth and reproduction of successive generations of N.lugens. Also, the enzymes activities and the DGE of brown planthopper were analyzed in this study. The results were as follows:1 Effects of elevated CO₂ on the life table of N.lugensThe results showed that elevated CO₂ significantly prolonged the larvae stage of nymph in F1 and F4（P < 0.05） compared with ambient CO₂ condition. Elevated CO₂ had no significant effect on the preoviposition period, adult longevity, brachypterous/ macropterous and female/male of N.lugens（P>0.05）. Nymph stage of N.lugens significantly shortened in F6 but prolonged in F10 under elevated CO₂（P<0.05）.Elevated CO₂ significantly affected the weight of N.lugens from F1 to F5（P<0.05）.Number of eggs in F7- F11 was significantly lower in elevated CO₂ treatments compaired with ambient CO₂ treatment（P<0.05）. The hatch rate of N.lugens in elevated CO₂ was significantly lower than those in ambient CO₂ treatment（P < 0.05）.2 Effects of elevated CO₂ on the enzymes activities of N.lugensElevated CO₂ significantly affected the total protein of N.lugens. The total protein of N.lugens increased significantly in F5 but decreased in F20 under elevated CO₂（P < 0.05）. There were no significant difference in Alkaline phosphatase activites of N. lugens in F5, F14 and F20 between elevated CO₂ and ambient CO₂ treatments, however, the Alkaline phosphatase activity of N.lugens increased significantly in F10 but decreased significantly in F21 under elevated CO₂. The Peroxidase activity of N.lugens decreased significantly in F5 under elevated CO₂ compared with ambient CO₂ condition（P<0.05）, but the Peroxidase activity of N. lugens increased significantly in F10 and F15 under 750 μL/L treatment; Elevated CO₂ had no significant effect on the Superoxide dismutase activity and Catalase activities of N. lugens（P>0.05）, but the Catalase activity of N.lugens increased significantly under CO₂ concentration of 750 μL/L in F10 and F20 as well as Superoxide dismutase activity in F10 and F21. The Catalase activity of N.lugens increased significantly in F20 as well as Superoxide dismutase activity in F15 and F20 under CO₂ concentration of 550 μL/L（P<0.05）. Elevated CO₂ significantly decreased the True choline esterase activity and the Glutathione sulfurtransferase activity of N.lugens increased significantly in F20 under elevated CO₂.3 DGE results of of N. lugens under different CO₂ levelsThe DGE results showed that elevated CO₂ significantly affected the express of genes. With the increase of CO₂ contration, more different genes were observed in elevated CO₂ concentration. Among the differentially expressed genes, most of them are related to the biological process regulation pathways.