Effects of continuous versus pulsed drought on mycorrhiza-crop-aphid interactions

连续干旱与脉冲干旱对菌根-作物-蚜虫相互作用的影响

• 批准号: 365450363
• 负责人: Professorin Dr. Caroline Müller
• 金额: --
• 依托单位: Arbeitsgruppe Chemische Ökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/365450363?language=en
• 关键词: Effects; continuous; versus; pulsed; drought

Global change scenarios predict scarcer water availability together with increasing temperatures, leading to longer drought periods. Imbalances in water supply mediate changes in resource allocation of plants and cause various physiological responses, such as closure of stomata and suppressed photosynthetic rates. These responses affect the biosynthesis of plant metabolites, which has consequences on herbivores and pathogens that depend on the plant quality. For example, the plant stress hypothesis predicts that aphids perform better on drought-stressed plants. Furthermore, most plants are associated with symbiotic fungi, forming an arbuscular mycorrhiza (AM), which can, amongst other effects, alleviate drought stress of plants. While many studies have investigated the effects of continuous drought stress on plant growth, physiology and chemistry, pulsed drought stress events are much more realistic. Moreover, the combined effects of drought and AM on aphids have been neglected. Therefore, in this proposal the effects of different drought regimes (pulsed drought stress versus continuous stress versus well-irrigated) on morphological, physiological or chemical responses of the crop plant wheat and their main aphid pest will be studied in presence or absence of AM. Effects of drought regime and AM status on plant growth traits and relative changes in hydration status will be monitored. Aphids will be reared on plants of the different treatments and various performance traits and the population growth measured to test the plant stress, pulsed stress and plant vigour hypotheses. In parallel, the chemical composition of phloem exudates will be analysed using metabolomics approaches. Multivariate statistics will allow us to make predictions about the role of specific phloem metabolomes for aphids. Subsequently, the role of the ratio of carbohydrates to amino acids to specific secondary metabolites will be tested using artificial diets. Metabolites will be selected that differ in concentration between the phloem of the plant treatments. Understanding the mycorrhiza-crop-aphid interactions under expected climate change scenarios may help to develop improved planting strategies and to establish cultivars with a high drought tolerance and high aphid resistance. Furthermore, the knowledge about the mechanisms underlying effects of pulsed drought stress on aphid population growth may allow for prediction of outbreaks.

全球变化情景预测，水资源将更加稀缺，气温将不断上升，导致干旱期延长。水分供应的不平衡调节了植物资源分配的变化，并引起各种生理反应，如气孔关闭和光合速率抑制。这些反应影响植物代谢产物的生物合成，这对依赖于植物质量的食草动物和病原体产生影响。例如，植物胁迫假说预测蚜虫在干旱胁迫的植物上表现更好。此外，大多数植物与共生真菌相关联，形成丛枝菌根（AM），其可以减轻植物的干旱胁迫。虽然许多研究已经研究了连续干旱胁迫对植物生长、生理和化学的影响，但脉冲干旱胁迫事件更现实。此外，干旱和AM真菌对蚜虫的联合作用被忽视。因此，在本提案中，将在存在或不存在AM的情况下研究不同干旱制度（脉冲干旱胁迫与连续胁迫与充分灌溉）对作物植物小麦及其主要蚜虫害虫的形态、生理或化学反应的影响。将监测干旱状况和AM状态对植物生长性状的影响以及水合状态的相对变化。将蚜虫饲养在不同处理和各种性能性状的植物上，并测量种群生长以测试植物胁迫、脉冲胁迫和植物活力假设。与此同时，韧皮部分泌物的化学成分将使用代谢组学方法进行分析。多元统计将使我们能够预测特定韧皮部代谢组对蚜虫的作用。随后，将使用人工饲料测试碳水化合物与氨基酸的比例对特定次级代谢产物的作用。将选择在植物处理的韧皮部之间浓度不同的二甲双胍。了解预期气候变化情景下的菌根-作物-蚜虫相互作用可能有助于制定更好的种植策略，并建立具有高耐旱性和高蚜虫抗性的品种。此外，脉冲干旱胁迫对蚜虫种群增长的影响机制的知识可能允许预测的爆发。