Networks of the symbiosis-immunity continuum in plants

Plants continuously interact with diverse microbes. Forming essential symbiotic relationships promotes plant growth, while defending against harmful microbes prevents disease. Plants resist pathogens by detecting molecules released from microbes. Beneficial microbes distinguish themselves from harmful pathogens before establishing symbiosis by releasing molecules and suppressing plant defenses during the infection and colonization stages. Despite their distinct outcomes, symbiotic and immune responses lie on a continuum and share key features, including dynamic cellular remodeling, metabolite rearrangement, and the maintenance of defenses against pathogens. This review explores the regulatory networks governing these processes, highlighting the shared and unique molecular mechanisms underlying symbiotic and immune responses. Understanding how plants integrate environmental signals to balance symbiotic compatibility and defense will provide valuable insights into optimizing plant health and productivity in changing ecosystems.