Exploring the role of plant associating bacteria as bioinoculants and their beneficial effects in phytostimulation: A review

Abstract

With an increase in global demand for food without unwanted environmental issues stresses a need for sustainable agriculture. Up till now, conventional agricultural methods focused on obtaining great crop yields from the use of chemical fertilizers but overlooked the hazardous concerns that are leading to soil depletion. These chemical fertilizers adversely affect soil structure, decrease fertility, damage soil flora, and lead to soil erosion. In this scenario, understanding the natural mechanisms of plant-microbe interactions in the rhizospheric environment can potentially lead a way towards eco-friendly agriculture, as the plant associating bacteria prompting phytostimulation can be the key players in unlocking sustainable alternative for conventional fertilizers. Plant growth-promoting bacteria (PGPB) are a distinct class of soil microorganisms that promote plant growth and yields by enhancing nutrient delivery and shielding the plants against diseases. Nitrogen-fixing bacteria such as Rhizobium and Azotobacter, for instance, fix atmospheric nitrogen into a usable form for plants, which minimizes synthetic fertilizers' requirement. Some other PGPB genera such as Pseudomonas and Bacillus induce root and shoot elongation by synthesizing phytohormones. These bacteria also provide protection to plants by synthesizing antimicrobial substances and increasing the competitive nature of the rhizosphere. Bacteria like Azospirillum, Enterobacter, and Flavobacterium also stimulate plant growth by producing phytohormones under specific environmental conditions. Utilization of PGPB as bio-stimulants in agriculture is a promising method for sustainable agriculture, minimizing dependence on chemical fertilizers and maintaining soil health. This approach would play an important role in sustaining a balanced ecosystem along with increasing agricultural productivity.