Arbuscular mycorrhizal fungi and their role in plant disease control: A state-of-the-art

Abstract

Arbuscular mycorrhizal fungi (AMF) play a crucial role in plant health and growth by forming symbiotic relationships with most vascular plant species. Beyond their well-documented contributions to nutrient uptake and resilience to various stresses, AMF have been shown to protect plants from phytopathogen attacks, offering an ecological alternative to conventional pesticide-based approaches. This review summarizes recent advances in understanding the environmental and biological characteristics of AMF, with a focus on their multifunctional mechanisms for phytopathogen control. These mechanisms include competition with soil-borne pathogens, modulation of plant immune responses through induced systemic resistance (ISR), and shifts in the taxonomic and functional diversity and composition of the soil and root microbiomes. By stimulating plant defenses, producing antimicrobial metabolites, and optimizing root architecture, AMF play an important role in protecting plants against a wide range of fungal, bacterial, viral, and nematode phytopathogens. Furthermore, this review explores the role of AMF in improving soil health, a key factor in sustainable disease management, by influencing soil characteristics, nutrient cycling, and microbial activity. The integration of AMF into sustainable agricultural practices, such as no-till farming, organic farming, and biological control inoculants, is also discussed. However, challenges remain regarding their variable field efficacy and the costs associated with large-scale production and formulation of AMF-based products. Further research on OMICS technologies related to AMF is essential to harness their potential as bioagents. A comprehensive understanding of the relationships between plants, AMF, microbiomes, and phytopathogens is critical for advancing sustainable and ecological agriculture systems. • AMF suppress plant diseases by enhancing plant immunity and competing with pathogens. • AMF trigger Induced Systemic Resistance (ISR), strengthening plant defenses against infections. • AMF improve soil microbiome diversity, creating an unfavorable environment for pathogens. • AMF act as natural biocontrol agents, reducing the need for chemical pesticides. • Integrating AMF into biocontrol strategies supports sustainable disease management.