Dissection of CrRLK1L signalling pathways regulating disease susceptibility and resistance to powdery mildew

花楸受体样激酶1-LIKE （CrRLK1L）蛋白是控制多种生理反应的重要受体。CrRLK1L FERONIA （FER）与其内源性快速碱化因子（RALF）肽配体一起在植物生长、发育和免疫过程中发挥核心作用。FER是模式触发免疫（PTI）和抗菌耐药的积极调节剂，通过以RALF肽依赖的方式促进配体诱导的微生物相关分子模式（MAMP）识别复合物的形成。相比之下，在白粉病感染过程中，FER是一种易感因子，其在多种植物微生物相互作用中的潜在机制尚不清楚。我们发现其他已知的FER信号成分调节植物对白粉病的适应，这表明RALF-FER代表了一条被适应性白粉病真菌劫持的途径。在这里，我们将分析白粉病易感性中FER的机制基础，并剖析其在抗菌耐药过程中区分功能多样性的信号通路。THESEUS1 （THE1）是与FER相关的CrRLK1L，但在对白粉病的基础抗性中起积极作用，这表明CrRLK1L的库决定了阳性和阴性感染的结果。我们将探索拟南芥CrRLK1Ls的功能多样性，以阐明导致疾病易感性或抗性的分子机制。FER和相关的CrRLK1Ls在所有陆地植物中都是保守的，在物种间可能具有相似的功能。大麦有6个相近的FER同源物，这表明该蛋白多样化，并提出了单个大麦同源物在不同植物微生物相互作用中接管多功能拟南芥蛋白特定作用的假设。我们希望探索大麦中FER的功能多样性，为未来的作物改良策略提供可转移的知识。

CATHARANTHUS ROSEUS RECEPTOR-LIKE KINASE 1-LIKE (CrRLK1L) proteins are important receptors controlling diverse physiological responses. Together with its endogenous RAPID ALKALINISATION FACTOR (RALF) peptide ligands, the CrRLK1L FERONIA (FER) plays central roles during plant growth, development and immunity. FER is a positive regulator of pattern-triggered immunity (PTI) and antibacterial resistance by facilitating the formation of ligand-induced microbe-associated molecular pattern (MAMP) recognition complexes in a RALF peptide-dependent manner. By contrast, FER functions as a susceptibility factor during powdery mildew infection and the underlying mechanism for FER`s role during diverse plant microbe interactions remains unknown. We show that other known FER signalling components modulate plant powdery mildew accommodation, suggesting that RALF-FER represents a pathway hijacked by adapted powdery mildew fungi. Here, we will analyse the mechanistic basis of FER during powdery mildew susceptibility and dissect signalling pathways distinguishing its functional diversity during antibacterial resistance. THESEUS1 (THE1) is a CrRLK1L related to FER but plays a positive role in basal resistance to powdery mildew, suggesting that the repertoire of CrRLK1Ls determine positive and negative infection outcomes. We will explore the functional diversity of Arabidopsis CrRLK1Ls to elucidate the molecular mechanisms that result in disease susceptibility or resistance. FER and related CrRLK1Ls are conserved among all land plants with likely similar functions across species. Barley has six close FER homologs, suggesting that the protein diversified and raising the hypothesis that individual barley homologs take over specific roles of the multifunctional Arabidopsis protein during distinct plant microbe interactions. We want to explore the functional diversity of FER in barley to generate transferable knowledge for future crop improvement strategies.