Biotechnological advances in plant growth-promoting rhizobacteria for sustainable agriculture

The rhizosphere, the soil zone surrounding plant roots, serves as a reservoir for numerous beneficial microorganisms that enhance plant productivity and crop yield, with substantial potential for application as biofertilizers. These microbes play critical roles in ecological processes such as nutrient recycling, organic matter decomposition, and mineralization. Plant growth-promoting rhizobacteria (PGPR) represent a promising tool for sustainable agriculture, enabling green management of crop health and growth, being eco-friendly alternatives to replace chemical fertilizers and pesticides. In this sense, biotechnological advancements respecting genomics and gene editing have been crucial to develop microbiome engineering which is pivotal in developing microbial consortia to improve crop production. Genome mining, which involves comprehensive analysis of the entire genome sequence data of PGPR, is crucial for identifying genes encoding valuable bacterial enzymes and metabolites. The CRISPR-Cas system, a cutting-edge genome-editing technology, has shown significant promise in beneficial microbial species. Advances in genetic engineering, particularly CRISPR-Cas, have markedly enhanced grain output, plant biomass, resistance to pests, and the sensory and nutritional quality of crops. There has been a great advance about the use of PGPR in important crops; however, there is a need to go further studying synthetic microbial communities, microbiome engineering, and gene editing approaches in field trials. This review focuses on future research directions involving several factors and topics around the use of PGPR putting special emphasis on biotechnological advances.