The Role of Phyllosphere Microbiome in Enhancing Plant Resistance to Pathogens and Environmental Stressors

The phyllosphere is an aerial environment on the surface of plants, and it harbors a wide variety of dynamic microbiomes, including bacteria, fungi, and other microorganisms. Phyllosphere microorganisms greatly help plants to resist phytopathogens by mechanisms such as antibacterial compound synthesis, competitive exclusion, modulation of plant immune response, siderophore production, etc. The diversity and composition of the phyllosphere microbiomes are influenced by factors like plant genotype, environment, and agricultural practices, thereby shaping the plant defense mechanism. Thus, the phyllosphere microbiome acts as an intermediary for plant defense against biotic and abiotic stresses. Recognition of the complex interaction between microbially allied leaf-dwelling microbes and plants not only illuminates the intricacy of ecological relationships but also provides novel insights into improving crop resistance and ecosystem regulation. In this review, various defense systems employed by phyllosphere microbiome against various diseases are elaborated.