Discovery of a symbiotic signalling mechanism from maize.

共生体是地球上生命的基础。一个这样的例子，被称为丛枝菌根（AM）共生，真菌和植物之间的进化，以促进矿物质从土壤中吸收约450百万年。这种共生安排是如此普遍，它影响生态系统的生产力，并被认为是作物生产力和可持续性的根本重要性。因此，对支撑AM共生发展和功能的过程的理解在整个植物界具有普遍意义。功能性共生体的建立依赖于信号的微调编排，以实现相互作用的植物和AM真菌的协调。突变体植物的鉴定和分析已经形成了我们理解支持种间串扰允许这种共生的分子机制的基石。植物和AM真菌在根际的相互识别是共生结果的核心，目前知之甚少。Paszkowski实验室之前已经发现了谷物中调节共生前识别的关键基因[Gutjahr et al.（2015）Science 350：1521; Nadal et al.（2017）Nature Plants 3：17073]，最近，已经鉴定出了独立于丛枝菌根（ina）玉米突变体。玉米植株表现出对AM真菌的敏感性完全丧失，然而，这可以通过添加野生型而不是突变体根分泌物来补充。这是一个独特的表型，以前没有被描述过，这表明INA是一个新的途径的一部分，不可或缺的前共生信号在maize. positivecloning揭示，缺失与三个候选基因共分离的突变表型。为了发现INA基因的同一性，目前正在生产其他CRISPR/Cas9编辑的玉米等位基因，并将于2020年底上市。这18个月的资助的目的是使用新的玉米突变体材料来发现INA基因的身份，采用我们的标准表型分析方案。此外，它旨在提供一个第一次深入了解INA的作用，通过确定转录组基础的INA无法从事与AM fungies.Knowledge的INA基因的性质将指导未来的研究方向，并将铺平道路，发现一种新的通信策略，为地球上最普遍的植物共生。

Symbioses are fundamental to life on the Earth. One such example, known as arbuscular mycorrhizal (AM) symbiosis, evolved between fungi and plants to facilitate mineral uptake from the soil around 450 mya. This symbiotic arrangement is so widespread that it impacts on ecosystem productivity, and is considered of fundamental importance for crop productivity and sustainability. Generating understanding of the processes that underpin AM symbiosis development and functioning are thus of universal relevance across the plant kingdom. The establishment of functional symbioses relies on the fine-tuned orchestration of signals to achieve coordination of the interacting plant and AM fungus. Identification and analysis of mutant plants have formed the bedrock of our understanding of the molecular mechanisms that underpin the interspecies crosstalk allowing this symbiosis. Reciprocal recognition and plant and AM fungi in the rhizosphere are central to the outcome of the symbiosis and presently poorly understood. The Paszkowski lab has previously discovered key genes from cereals that condition pre-symbiotic recognition [Gutjahr et al. (2015) Science 350:1521; Nadal et al. (2017) Nature Plants 3:17073] and most recently, has identified the independent of arbuscular mycorrhiza (ina) maize mutant. Maize ina plants show a complete loss of susceptibility to AM fungi, which can however be complemented by the addition of wild-type but not ina mutant root exudates. This is a unique phenotype that has not been described before, suggesting that INA is part of a new pathway, indispensable for pre-symbiotic signalling in maize.Positional cloning revealed that a deletion with three candidate genes co-segregated with the mutant phenotype. To discover the INA gene identity additional CRISPR/Cas9-edited maize alleles are presently produced and will be available at the end of 2020. It is the aim of this 18 months grant to use the new maize mutant material to discover the INA gene identity, employing our standard phenotyping protocols. In addition it seeks to provide a first insight into the role INA plays by determining the transcriptome underpinning of the inability of ina to engage with AM fungi.Knowledge of the nature of the INA gene will guide future research directions and will pave the way to discover a novel communication strategy for the most prevalent plant symbiosis on Earth.