Receptor Kinases (RKs) and Receptor-Like Proteins (RLPs) constitute plant cell surface-localized Pattern-Recognition Receptors (PRRs) that sense danger signals (patterns) derived from either the host or pathogens during infection.Upon the perception of danger signals, PRRs activate a variety of intracellular phosphorylation events to orchestrate diverse immune responses that together fend off invading pathogenic microbes.