Harnessing Biocontrol Potential of Endophytic Xylaria spp. against Plant Pathogens: Mechanisms and Applications

Plant diseases cause substantial crop loss globally, with fungal pathogens accounting for the majority of infections, leading to significant economic loss. The environmental concerns associated with chemical pesticides and other limitations have made it necessary to search for sustainable alternatives. Endophytic fungi, particularly the species of Xylaria (family Xylariaceae), have emerged as promising biocontrol agents due to their ecological adaptability and ability to colonize plant tissues asymptomatically. Xylaria spp. produce a wide range of bioactive secondary metabolites which exhibit antifungal, antibacterial, antioxidant, and phytotoxic activities. These fungi suppress pathogens through multiple mechanisms, including competition for nutrients and space, production of diffusible and volatile metabolites, quorum-sensing inhibition, and induction of host plant resistance. In addition to plant protection, Xylaria spp. contribute significantly to plant growth promotion through nutrient solubilization, siderophore production, and enhanced physiological performance. Applications in nanotechnology, such as green synthesis of nanoparticles, have enhanced their antimicrobial efficacy. Advances such as the OSMAC approach have further expanded their metabolic diversity and potential for novel compound discovery. However, challenges include limited knowledge of host specificity and formulation constraints hinder large-scale application. Future research should prioritise omics-based studies, formulation standardization, and field validation. Collectively, these attributes highlight the significant potential of endophytic Xylaria spp. for use as eco-friendly bioagents in sustainable agriculture, as well as valuable sources of novel compounds for pharmaceutical and biotechnological applications.