The Hidden Workforce of Sustainable Agriculture: Plant Interactions with Arbuscular Mycorrhizal Fungi and Rhizobacteria

The increasing demand for food driven by population growth, together with climate change, environmental degradation, and the excessive dependence of modern agriculture on synthetic fertilizers and pesticides, has intensified the search for sustainable strategies capable of maintaining crop productivity while reducing environmental impacts. Beneficial interactions between plants, arbuscular mycorrhizal fungi (AMF), and rhizobacteria (RHZb) represent one of the most successful evolutionary adaptations of terrestrial plants and have emerged as fundamental components of climate-smart and sustainable agriculture. Here, we comprehensively review the evolutionary origin of these interactions, the molecular and physiological mechanisms underlying plant recruitment, recognition, and establishment of symbiotic and associative relationships, as well as the structural adaptations that support nutrient exchange between partners. Particular emphasis is given to the complementary roles of AMF and RHZb in improving nutrient acquisition, reprogramming plant phytohormone networks, and enhancing tolerance to biotic and abiotic stresses through coordinated physiological, biochemical, and molecular responses. Finally, recent case studies are discussed to demonstrate how these microorganisms contribute to reducing fertilizer inputs, increasing crop productivity, improving stress resilience, and supporting ecological restoration under diverse agricultural systems. Collectively, the evidence highlights that integrating AMF and RHZb into crop management offers a robust biological strategy to enhance resource-use efficiency and agricultural resilience, providing a solid scientific foundation for the development of next-generation bioinoculants and more sustainable food production systems.