The Role of Phyllosphere Microbes and Viruses in Biocontrol of Pathogenic Fungi

The phyllosphere, the aerial surfaces of plants, represents a primary entry point for airborne fungal pathogens, posing a critical challenge to plant health and productivity. The phyllosphere hosts diverse microbial communities that play a pivotal role in suppressing foliar pathogens through complex ecological interactions. In this mini review, we synthesise recent advances in understanding how phyllosphere microbial diversity contributes to fungal pathogen suppression through multiple ecological mechanisms, including resource competition, secretion of antifungal metabolites, contact-dependent killing and activation of host immune responses. We highlight emerging evidence on the role of viruses in controlling fungal pathogens and propose a conceptual framework based on virus-mediated strategies for fungal disease control. We emphasise that better mechanistic understanding of plant-fungus-microbiota interactions is critical to developing sustainable and microbiota-based approaches for plant resilience enhancement and global food security within a One Health framework.