Plant-fungus synergy against soil salinity: The cellular and molecular role of arbuscular mycorrhizal fungi

Arbuscular mycorrhizal fungi (AMF) play a crucial role in disease control by establishing symbiotic relationships with plant roots. AMF improve salinity tolerance in plants by regulating the Na+/K+ ratio through selective ion transport and mediate osmotic regulation by inducing the accumulation of osmotic-compatible solutes such as glycine betaine and proline to enable plant cells to maintain water content and the metabolic balance. AMF can also activate antioxidant defense responses by stimulating enzymes that protect plant cells from harmful oxidation and pathological infections. Plant salinity tolerance induced by AMF depends on abscisic acid (ABA)-dependent signaling mechanisms, calcium-calmodulin-dependent pathways, and reactive oxygen species (ROS)-modulated mitogen-activated protein kinase (MAPK) cascades. Therefore, future research should focus on optimizing the production and field efficacy of AMF-based inoculants, including their combined use with microbial biostimulants, to support the implementation of sustainable agricultural practices.