Organic pollutant-induced long-distance ROS signaling drives plant systemic acquired acclimation via rhizomicrobiota

Plants can recruit beneficial rhizomicrobes to combat environmental stimuli, but the upstream signaling through which plants sense stress to initiate rhizomicrobial recruitment still remains unclear. This study elucidates the role of long-distance ROS signaling in driving the recruitment of beneficial rhizobacteria to establish systemic acclimation following local organic pollutant stress. Plant leaves sense various organic pollutants to generate ROS, followed by the occurrence of a long-distance ROS wave from leaves to roots via a Ca²⁺-RBOH-ROS signaling module. Elevated ROS in roots plays dual functions. First, ROS stimulates plant carbon release into the rhizosphere by increasing the permeability of root cell membranes. The released carbon flux enriches plant-beneficial bacterial genera, which in turn promotes plant growth and pollutant degradation. Second, NO acts downstream of ROS to loosen root cell walls, facilitating rhizobacterial colonization. Our findings show how plants deploy systemic signaling acquire help from rhizomicrobes, extending our understanding of plant environmental adaptability.