Immune Receptors in Plant Defense: Recognizing Pathogens and Triggering Innate Immune Responses

Plant pathogens cause substantial crop yield losses worldwide. Developing resistant plant varieties requires a thorough understanding of how plants perceive pathogens and respond to necrotrophic, hemi-biotrophic, and biotrophic threats. Pathogen recognition relies on elicitors, effectors, and signaling processes, which activate defense mechanisms in plants. The cell wall, serving as a physical barrier, plays a crucial role in protection. However, pathogens have developed strategies to bypass this barrier and penetrate the plasma membrane. Research has revealed mechanisms through which plant immune systems recognize microbial pathogens. Microbe-associated molecular patterns (MAMPs), conserved molecules produced by invading microbes, are detected by pattern recognition receptors (PRRs) on plant cells. This interaction triggers immune responses that restrict pathogen growth. Furthermore, recent studies have identified components of the plant immune system that facilitate beneficial interactions with microbes, supporting the colonization of microbial communities that positively influence the host. This short review focuses on the role of PRRs in detecting microbial epitopes and transmitting signals to initiate antimicrobial defenses in plants.