Signal communication during microbial modulation of root system architecture

Abstract Every living organism on Earth depends on its interactions with other organisms. In the rhizosphere, plants and microorganisms constantly exchange signals and influence each other’s behavior. Recent studies have shown that many beneficial rhizosphere microbes can produce specific signaling molecules that affect plant root architecture and therefore could have substantial effects on above-ground growth. This review examines these chemical signals and summarizes their mechanisms of action, with the aim of enhancing our understanding of plant–microbe interactions and providing references for the comprehensive development and utilization of these active components in agricultural production. In addition, we highlight future research directions and challenges, such as searching for microbial signals to induce primary root development.