Biotic regulation of symbioses signalling

氮(N)是植物生产力的主要常量养分。一个矛盾的现象是，土壤中的氮素利用率很低，导致为了维持作物产量而广泛而昂贵地施用肥料。自20世纪初以来，氮肥的使用量逐渐增加，以满足不断增长的人口的需求。矛盾的是，据估计，提供给土壤的氮有50-70%流失了，导致土壤和水污染，并通过排放一氧化二氮导致全球变暖。降低肥料投入，培育氮素利用效率较高的作物是植物营养研究的主要目标之一。根茎豆科植物共生体通过与固氮细菌和输送磷酸盐的丛枝菌根的联系，为植物提供天然肥料。然而，在根际，植物根系暴露于包括病原体在内的一系列微生物中。有益的共生生物必须避开植物的防御才能在寄主的根上定居。该项目将结合体内成像分析、遗传学、分子生物学和蛋白质组学，在共生和防御之间的相互作用中定义一种新的分子机制。

Nitrogen (N) is a major macronutrient for plant productivity. As a paradox, N is poorly available in soils, leading to extensive and costly fertiliser applications to sustain crop yields. Since the early 20th century, the use of N fertilizers has gradually increased to fulfil the demand of a growing population. Paradoxically, it has been estimated that 50-70% of the nitrogen provided to the soil is lost, giving rise to soil and water pollution as well as global warming through emissions of nitrous oxide. Lowering fertilizer input and breeding crops with better nitrogen use efficiency is one of the main goals of plant nutrition research. Root legume symbioses are natural fertilizer for the plants via the association with nitrogen fixing-bacteria and phosphate delivering arbuscular mycorrhiza. However, in the rhizosphere, plant roots are exposed to an array of microorganisms including pathogens. Beneficial symbiotic organisms must evade plant defences in order to colonize host roots.This project will define a novel molecular mechanism at the interplay between symbioses and defence using a combination of in vivo imaging analyses, genetics, molecular biology and proteomics.