植物防御演化对地上和地下昆虫互作关系的影响及其内在机制

地上昆虫-植物-地下昆虫的相互作用关系是影响生态系统结构、功能和稳定性的重要关系之一。植物防御演化往往影响地上和地下昆虫的互作关系，相关研究有助于理解植物与昆虫的协同进化过程，具有重要的进化生态学意义。入侵植物的地上和地下昆虫群落从原产地到入侵地往往发生变化，导致其防御能力发生演化，进而可能改变昆虫的互作关系，是研究植物防御演化对昆虫互作关系影响的理想体系。本项目以入侵植物乌桕为对象，选取2组具有明确亲缘关系、不同防御能力的原产地和入侵地种群（江苏-德克萨斯，广东-乔治亚），结合多种类型地上和地下昆虫（专食性和广食性昆虫、咀嚼式和刺吸式昆虫），通过室内和田间实验明确植物防御演化对昆虫互作关系的影响，通过化学和分子手段揭示其内在机制。研究结果有助于阐明植物对地上和地下昆虫的生物调节作用，揭示植物地上和地下部防御演化的方向，并对农业害虫综合治理以及入侵植物生物防治具有重要意义。

The interaction among the aboveground insect, plant and belowground insect is one of the most important relationships that impact function and stability of ecosystem. Although plant-mediated interactions between above- and belowground insects have received considerable attention, the effects of adaptive evolution in plant defense on these interactions are largely unknown. In this context, invasive plant species offer excellent model systems. Invasive plant releasing from their co-evolved above- and belowground natural enemies may have led to change defense-related traits, which in true may affect the interactions between above- and belowground insects. In this study, we will examine the effects of adaptive evolution in plant defense on the interactions between above- and belowground insects using invasive plant Chinese tallow (Triadica sebifera) as a model species. To examine the interactive effects of above- and belowground insects and these difference among native and invasive populations, we will conduct laboratory and field experiments using 2 types of insect herbivores (specialist and generalist insects, chewer and phloem feeder) and 2 pairs of genetically related of native and invasive populations (Jiangsu-Texas, Guangdong-Georgia). To examine the chemical and molecular mechanisms underlying these insect herbivores interactions, we will measure the nutritious and secondary compounds and verify expression patterns of tannins related genes in both leaves and roots from native and invasive populations. This study will provide a better understanding of how adaptive evolution in plant defense will influence above- and belowground insects interactions, and how above- and belowground plant parts will evolve in defense under different insect selection. Furthermore, this study will have important implications for management of agricultural pests and biological control of invasive plant species.