Herbivore-Plant-Soil microbe interactions: who is helping whom

植物与环境相互作用，并在与昆虫/病原体的生物相互作用过程中经历表型变化。对生物胁迫因子的反应是广泛的，可以发生在地上和地下，系统地影响整个植物和周围的植物环境(叶圈/根际)。对昆虫食草动物定殖化最重要的反应之一是改变释放的外部化学信号，这可以通过招募食草动物天敌和向邻近植物发出信号来影响食草动物的生物学。此外，不同取食方式的食草动物可以诱导不同的化学信号通路。这些化合物在地下的释放会影响植物与与植物根系相关的土壤微生物群落的相互作用。土壤微生物群落的组成已经被认为是影响植物健康的一个重要因素。例如，固氮菌或菌根真菌等有益生物的积累可以改善植物的表现，而病原体的积累可以抑制植物的生长。在该项目中，我们假设：(1)地上草食动物的攻击将通过改变释放到土壤环境中的分泌物来改变地下的化学物质。(2)渗出物的这种改变将影响影响植物-微生物以及微生物-微生物相互作用的植物微生物群。昆虫-草食动物-植物-土壤微生物相互作用的后果对于通过了解地下信号化学导致抑制昆虫和病原体害虫的新干预措施而提高作物生产力至关重要。因此，本博士致力于解决以下问题：1.不同方式的地上害虫危害(吸食、咀嚼)如何影响根际微生物群落？2.微生物群落如何与含有亲脂小分子化学信号的植物根分泌物相互作用？3.根分泌物是否会导致根际长期变化，从而影响微生物/植物的演替？为了解决上述三个目标，学生将开展以下研究计划：基于3个目标：1.描述了在两种不同的食草动物取食模式(吸液和咀嚼树叶)下，通过小麦根系释放到根际的化合物(挥发性和非挥发性)是如何变化的。研究病虫害侵袭前后分泌物与根际微生物群落的相互作用。研究地下化学改造对植物系统的影响。

Plants interact with their environment and undergo phenotypic changes during biotic interactions with insects/pathogens. Responses to biotic stress factors are wide-ranging and can occur both above- and belowground, systematically affecting the whole plant and surrounding plant environment (phyllosphere/rhizosphere). One of the most important responses to insect herbivore colonization is the modification of external chemical signals released, which can impact on herbivore biology by recruitment of herbivore natural enemies, and by signalling to neighbouring plants. Furthermore, herbivores with different feeding modes can induce different chemical signalling pathways. The release of these compounds belowground can affect plant interactions with soil microbial communities that are associated with the plant root system. The composition of the soil microbial community has been recognized as an important factor in plant health. The accumulation of beneficial organisms such as nitrogen-fixing bacteria or mycorrhizal fungi for instance can improve plant performance, while the accumulation of pathogens can suppress plant growth.In the project, we hypothesize that:(1) Aboveground herbivore attack will change the chemistry belowground through modifications of exudates released into the soil environment.(2) This modification to exudates will influence the plant microbiome affecting plant-microbe as well as microbe-microbe interactions.The consequences of insect herbivore-plant-soil microbe interactions are vital to improving crop productivity through understanding of the signalling chemistry belowground leading to new interventions on suppression of insect and pathogen pests. Therefore, this PhD aims to address the following questions:1. How do different modes of aboveground insect pest damage (sucking, chewing) impact upon the rhizosphere microbiome?2. How do microbial communities interact with plant root exudates containing small lipophilic molecule chemical signals?3. Do root exudates lead to long-lasting changes in the rhizosphere which could affect microbial/plant succession?To address these three aims detailed above, the following programme of research will be carried out by the student, based around 3 objectives:1. 1 Characterise how chemical compounds released into the rhizosphere (volatile and non-volatile) through the wheat root system change under two different herbivore feeding modes (sap-sucking and leaf-chewing).2. Investigate how exudates interact with rhizosphere microbial communities before and after pest attack.3. Investigate the impact on the plant system by the modification of chemistry belowground.