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 plant senses stress to initiate rhizomicrobial recruitment still remains unclear. This study elucidates the ubiquitous role of plant long-distance ROS signaling in driving the recruitment of beneficial rhizobacteria for the establishment of plant systemic acclimation upon 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 Ca2+-RBOH-ROS signaling module. Elevated ROS in roots plays dual functions. First, ROS stimulates plant carbon release into rhizosphere by increasing the permeability of root cell membranes. The released carbon flux enriches plant-beneficial bacterial genera, which in turn promote plant growth and pollutant degradation. Second, NO actes as downstream of ROS to loosen root cell wall, facilitating rhizobacterial colonization. Our findings provide an answer to a pending question how plants deploy systemic signaling to ask for help from rhizomicrobes, extending our understanding for plant environmental adaptability.