United we stand: Plants that physically touch each other are more resilient to stress

Plants use sophisticated signaling networks to communicate with each other. While this process is thought to support the overall health and resilience of plant communities, it could also reflect eavesdropping between plants used for competition. Here we reveal that plants that physically touch each other aboveground are more resilient to excess light stress, and that this phenomenon is dependent on the ability of plants to exchange aboveground electric and H2O2 signals with each other. Using a mutant that is unable to transfer Ca2+/reactive oxygen species (ROS) signals but can transfer electric signals (hpca1), as a mediator/connector between different plants, we further separate electric from Ca2+/ROS plant-to-plant signals and transcriptional landscapes, and show that the transfer of Ca2+/ROS signals, as well as the function of several Ca2+/ROS-dependent transcripts, is required for excess light stress acclimation. Our study reveals that plants that live together and physically touch each other establish an aboveground community-wide signaling network that enhances their collective resilience to stress. TeaserPlants that physically touch and exchange aboveground signals with each other are more resilient to excess light stress.