Plant growth-promoting rhizobacteria biochemical pathways and their environmental impact: a review of sustainable farming practices

Abstract

Plant growth-promoting rhizobacteria (PGPR) are a crucial component of the soil microbiome. They have attracted noteworthy interest due to their plant growth- and health-enhancing effects. PGPR enhances plant growth through several biochemical pathways, such as phytohormone production, solubilizing plant-inaccessible phosphate, nitrogen fixation, siderophore production, and ACC deaminase activation. Collectively, these biochemical pathways contribute to improved nutrient uptake, plant growth, and stress tolerance, underscoring the importance of PGPR in sustainable agriculture. This review analyzes the existing research on PGPR, highlighting their associated biochemical pathways, molecular interactions, and ecological consequences in agriculture. The significant identified aspects include the synthesis of phytohormones, including cytokinins and auxins; phosphate solubilization; and nitrogen fixation, all essential for plant stress resistance and development. The review highlights the ecological and agricultural implications of PGPR. PGPR reduces reliance on chemical pesticides by naturally suppressing plant pathogens and reduces reliance on chemical fertilizers needed to improve nutrient uptake. The review addresses the potential challenges of complicated biochemical reactions related to PGPR–plant interactions, exploring how these reactions can be optimized for better plant growth and health. The review article discourses the challenges modeled by strain specificity, wide-ranging soil conditions, and potential environmental influences of PGPR. It also discusses the essentials for further research into new PGPR strains, long-term field studies, and biochemical pathways to advance sustainable agronomic practices.