Enhancing plant resistance to biotic stresses through rhizobacteria for sustainable agriculture

Abstract

Plant Growth-Promoting Rhizobacteria (PGPR) play a crucial role in the enhancement of plant growth. These microorganisms inhabit plant roots and positively influence plant growth through various mechanisms. PGPR facilitate nutrient absorption, combat pathogens, and regulate plant hormone levels. Their impact is achieved through direct actions such as hormone production, enhanced iron uptake via siderophores, phosphate solubilization, and emission of volatile compounds that affect plant signaling and metabolism. In addition, PGPR interactions with rhizosphere microorganisms and the soil indirectly improve plant growth. Numerous biotic stressors affect plant PGPR. The interaction between plants and microorganisms boosts the host resistance to biotic stress. This interaction also regulates the rhizosphere soil by converting organic compounds into plant-absorbable forms, increasing molecule mobilization, and supplying amino acids, carbohydrates, lipids, metabolites, and phytohormones to the host plants. In instances where plants do not secrete lipids, amino acids, carbohydrates, or terpenoids during these interactions, microorganisms contribute these compounds to plants. Investigating these mechanisms, along with changes in gene expression and receptor-mediated signaling in plants, is vital. Utilization of microbial sources as alternatives to conventional agricultural methods is a promising approach. Incorporation of these sources can enhance plant production, quality, growth, and yield.