Protecting plants from pathogens through arbuscular mycorrhiza: Role of fungal diversity

Arbuscular mycorrhizal (AM) fungi play a crucial role in protecting host plants from pathogens. AM fungal taxa show varying abilities to hinder the development of plant pathogens with various underlying mechanisms of action, and plant defense through mycorrhization should be viewed to have a continuum of several possible mechanisms. However, an additive or synergistic effect is not always achieved. This review examines the potential mechanisms by which AM fungi enhance plant tolerance and defense against pathogens, as well as the possible interactive mechanisms among AM fungal traits that may lead to facilitative and antagonistic effect on plant defense outcomes. It also provides evidence demonstrating the benefits of AM fungal consortia used so far to protect crop plants from various pathogens. It concludes by proposing some biotechnological applications aimed at unraveling the connections between AM fungal diversity and their function to enhance efficacy of plant pathogen protection.