Abstract
This Research Topic was launched in late 2021 in the frame of a broad initiative covering most sections of Frontiers in Plant Science. The call for papers attracted 14 original research, method, review and mini review papers by 74 authors, largely delivering our goal to provide a transversal insight into the advances in the major symbiotic plant-microbe interactions.The contributions embrace molecular, cellular, applicative and ecological aspects of mycorrhizas, symbiotic nitrogen fixation and plant interactions with beneficial endophytes or plant growth-promoting bacteria.