Plant Growth Promoting Phyllobacteria: an Effective Tool for Sustainable Agriculture

The phyllosphere, i.e., the above-ground portion of plants, exhibits an ecological niche for a diverse group of microbes, and the phyllosphere exudates provide proper nutrients, moisture, and pH for the phyllospheric microbes. The phyllosphere colonizing microbes may exhibit negative, positive, or neutral effects on the host plants. Some phyllosphere colonizing bacteria i.e., phyllobacteria show positive interactions with their host plants and improve plant health and productivity by regulating nutrient recycling, secreting phytohormones, and protecting plants from biotic and abiotic stresses. Such plant-beneficial phyllobacteria that improve plant growth, development, and productivity may be called plant growth-promoting phyllobacteria (PGPP). The PGPP are not highly explored compared to the rhizobacteria and are in the investigation phase. Therefore, understanding the interaction of phyllospheric microbes with their host plants is important from a scientific, agricultural, as well as economic point of view. This review provided a brief introduction to plant growth-promoting phyllobacteria and their involvement in plant growth promotion as well as enhancement in crop production in a sustainable manner. This article also summarized the recent research reports and the available knowledge on the application of plant growth-promoting phyllobacteria to sustainable agricultural practices.