Role of Plant Growth Promoting Rhizobacteria for Advanced Sustainable Agricultural Practices: A Review

Abstract

The role of PGPR in nutrient cycling, soil structure improvement, and soil pH modification. Traditional agriculture relies heavily on chemical inputs, which pose significant threats to the environment and deplete natural resources. The environmental challenges posed by chemical-based agriculture and emphasize the urgent need for sustainable alternatives in the face of climate change. Plant Growth-Promoting Rhizobacteria (PGPR) are beneficial soil microorganisms that enhance plant growth through various direct and indirect mechanisms, offering a sustainable approach to improving soil fertility and crop productivity. PGPR have emerged as a sustainable alternative, fostering plant development, and enhancing stress resilience. A comprehensive understanding of the underlying signalling pathways and stress management mechanisms is essential to maximizing their potential. Plant health has been demonstrated, nutrient uptake has improved, and environmental stress has been reduced with the help of PGPR. PGPR facilitate nitrogen fixation, phosphorus and potassium solubilization, and organic matter decomposition, enhancing nutrient availability and promoting plant growth. Their ability to produce exopolysaccharides contributes to soil aggregation, improving soil structure and water retention. Additionally, PGPR modifies rhizosphere pH, enhancing nutrient solubility and availability. PGPR also promote crop yield by enhancing root and shoot growth, improving seed germination, and increasing stress tolerance against drought, salinity, and heavy metal contamination. PGPR provides effective biocontrol against pathogens through antibiosis, competition, and induced systemic resistance (ISR), contributing to improved crop resilience. Despite their potential, several challenges hinder the widespread adoption of PGPR, including inconsistent field performance, limited shelf-life, compatibility issues with native soil microbiota, and regulatory barriers. Emerging approaches such as genetic engineering, multi-strain consortia, and nano-formulations are being developed to enhance PGPR efficacy and stability under diverse environmental conditions. Integrating PGPR with organic and chemical fertilizers presents a promising strategy for achieving higher yields while minimizing environmental impact. Research should focus on understanding PGPR-plant signalling pathways, optimizing formulation techniques, and developing policies to promote their commercial use. Collaborative efforts between researchers, industries, and policymakers are essential to enhance the application of PGPR in sustainable agriculture. Widespread adoption of PGPR-based technologies could significantly contribute to global food security, environmental sustainability, and the reduction of chemical inputs in agriculture. The potential of PGPR as a valuable tool for enhancing agricultural productivity through environmentally friendly practices. Future research should focus on developing efficient, cost-effective formulations and enhancing collaboration between researchers, policymakers, and industries to ensure global food security and environmental sustainability.