温度和CO2浓度升高下褐飞虱生理与行为响应及其调控机理研究

Atmospheric warming combined with carbon dioxide (CO2) level increased simultaneously under climate change, which may further influence crop production and the occurrence of herbivorous insect pests. Hereinto, there is a risk that the damage caused by pierce-feeding insect pests would become more serious and heavier due to their sucking damage on plant phloem. In this study, the key sucking-feeder, brown planthopper (BPH) Nilaparvata lugens will be selected, and the combined effects between elevated CO2 and temperature on N. lugens, based its host selection behavior and pierce-sucking behavior, and nutrition metabolism and development physiology, will be carried out following as: (1) The developmental physiology and occurrence pattern of BPH, and the molecular mechanisms of growth, development and reproduction based on the gene regulation by juvenile hormone and molting hormone, and vitellogenin etc.; (2) The digestive metabolism of BPH physiology, and the micro-mechanisms of nutrition utilization regulated by the key enzymes of sucrose and trypsin; (3) The pierce-phloem sucking behavior of BPH, and the molecular mechanisms of feeding behavior regulated by appetite gene of neuropeptide F and salivary secretion related genes; (4) Composition and content change of host volatiles, and host selection behavior of BPH, and the molecular mechanisms regulated by odorant binding protein genes and chemosensory protein genes. Moreover, the economic yield and grain-nutrition quality of rice will be welly assessed under climate change. The implementation of this project is necessary to make clear the molecular mechanisms to regulate the host selection and pierce-feeding behaviors, and nutrition metabolism and development physiology of pierce-sucking insect pests in response to climate change, and service for the damage prediction of pierce-sucking insect pests, and for the assessment on the economic yield of rice crop, simultaneously develop and improve the theory and practices of Entomology and Climate Change Biology.

气候变化下温度和大气CO2浓度同步升高，进而影响作物生产及其害虫发生；其中，取食为害植物韧皮部的刺吸类害虫有为害加重风险。本研究以水稻主要刺吸类害虫褐飞虱为对象，围绕其寄主选择、刺吸取食、营养代谢和发育生理，重点开展温度和CO2浓度升高联合作用下褐飞虱如下研究：（1）发育生理和种群灾变规律及其基于蜕皮和保幼激素、卵黄原蛋白等调控发育与繁殖的分子机理；（2）消化代谢生理及其基于蔗糖酶和胰蛋白酶等调控营养利用的微观机制；（3）刺吸取食行为及其基于食欲基因和唾液分泌相关基因调控取食行为的分子机理；（4）植物挥发物组分变化与寄主选择行为，及其基于气味结合蛋白和化学感受蛋白的分子调控机理。此外，评估气候变化下水稻经济产量及其稻谷品质。项目实施有助于明确刺吸类害虫应对气候变化的生理和行为表型及其内在调控机理，服务于气候变化下刺吸类害虫为害预测与水稻产量评估，并丰富昆虫学和气候变化生物学的理论与实践。

本项目开展CO2浓度和温度升高下水稻刺吸类害虫褐飞虱寄主选择、刺吸取食、营养代谢和发育生理响应及其调控机理研究，结果如下：（1）明确了CO2浓度和温度升高导致转Bt水稻组织内N素含量、C/N比和外源Bt蛋白含量变化，且受氮肥水平影响；（2）明确了高CO2浓度下氮肥水平通过影响转Bt水稻外源基因启动子区和编码区甲基化来增加转Bt水稻Bt毒素含量；（3）明确了CO2浓度升高显著降低褐飞虱种群发生量，CO2浓度和温度升高联合作用不会影响褐飞虱种群发生量，尤其在增施氮肥情况下；（4）明确了基于营养代谢生理变化的褐飞虱应对气候变化的响应机理，即CO2浓度升高影响寄主水稻韧皮部营养和次生抗虫物质含量，进而影响褐飞虱体内营养成分变化，导致其营养代谢生理变化，显著提高5龄若虫体内淀粉酶关键基因Mal A3表达水平，并显著降低脂肪酶关键基因（Lip1）和胰蛋白酶关键基因（Trp5）表达水平，最终影响褐飞虱生理发育；（5）明确了基于生长发育和繁殖调控的褐飞虱应对气候变化的响应机理，即CO2浓度升高通过影响褐飞虱若虫保幼激素（JH）和蜕皮激素（MH）及雌成虫卵黄原蛋白（Vg）合成关键基因表达来加快若虫发育速率，并提高雌成虫繁殖力；（6）明确了CO2浓度升高对褐飞虱寄主选择行为和刺吸取食行为影响表型及其调控机理，即CO2浓度升高显著影响水稻挥发物（VOCs）组分含量，并显著提高褐飞虱气味结合蛋白基因OBP1和OBP2、化学感受蛋白基因CSP8，以及食欲基因NPF和sNPF、甜味受体基因Gr64f表达水平，并显著降低苦味受体基因Gr12和Gr14表达水平，表明CO2浓度升高下褐飞虱通过下调苦味受体关键基因表达来降低对寄主水稻防御物质的敏感性，加剧其刺吸取食为害；（7）提交了年度进展报告3份、项目结题报告1份；发表研究论文21篇（其中，第1标注论文9篇），授权实用新型专利5项；培养硕士生7人、博士生8人（毕业博士生4人、硕士生3人）；此外，派出1人出国参加2019年度美国昆虫学年会、1人前往美国Texas A&M University开展访学。