Biological Management of Soil-Borne Pathogens Through Tripartite Rhizosphere Interactions with Plant Growth-Promoting Fungi

Soil-borne plant pathogens pose a serious threat to global food security by causing extensive yield losses and compromising crop quality. Conventional chemical-based control methods often prove inadequate, environmentally harmful, and disruptive to beneficial soil microbiota, highlighting the urgent need for sustainable alternatives. Plant growth-promoting fungi (PGPF) have emerged as effective biocontrol agents capable of suppressing diverse soil-borne pathogens while simultaneously enhancing plant growth and resilience. This review synthesizes current knowledge on the tripartite interactions among plants, pathogens, and PGPF within the rhizosphere, with emphasis on their roles in disease suppression, rhizosphere competence, and plant health promotion. The findings highlight that PGPF such as Trichoderma, Penicillium, Aspergillus, non-pathogenic Fusarium, hypovirulent binucleate Rhizoctonia and sterile fungi can significantly reduce diseases caused by fungi, oomycetes, bacteria, nematodes, and protists through mechanisms including antibiosis, hyperparasitism, competition, and induction of systemic resistance. Evidence also indicates that consortium approaches and bioformulations enhance field efficacy compared to single-strain applications. Despite this progress, challenges such as variability in field performance, limited shelf life of inoculants, and gaps in understanding ecological interactions constrain large-scale use. Overall, the review underscores that PGPF-based strategies represent a promising and sustainable alternative to chemical pesticides, with strong potential for integration into holistic crop disease management under changing climatic conditions.