Impact of plant growth-promoting rhizobacteria (PGPR) on plant nutrition and root characteristics: Current perspective

Through a variety of mechanisms, including increasing the amount of readily available mineral nutrients, regulating phytohormone levels, and biocontrol of phytopathogens, plant growth-promoting rhizobacteria (PGPR) associated with the plant rhizosphere either directly or indirectly stimulates plant growth and development. The establishment, survival, and persistence of PGPR inoculants are widely acknowledged to be contingent upon these two parameters, in addition to the intricate network of interactions within the rhizosphere. In general, the soil is a moist environment with significant amounts of carbon that have been degraded and harbors a large population of soil microbes. The rhizo-microbiome is crucial to agriculture because a wide variety of root exudates and plant cell debris attract unique and distinct patterns of microbial colonization. The rhizo-microbiome plays a crucial role in the manufacture and regulation of extracellular molecules, including hormones, secondary metabolites, antibiotics, and various signaling chemicals. Additionally, the microbial composition within the rhizo-microbiome influences soil texture enhancement. Research has shown that PGPR can be used to treat plants or inoculate plants to promote plant development. PGPR alters the physiology of the entire plant, which enhances nutrient uptake and affects the effectiveness of root activity. The specific biochemical processes of plants involved in this phenomenon are often not well understood. Nevertheless, new studies have shed light on the mechanisms via which signaling by PGPR can induce various plant responses, both at the local and systemic levels. Insufficient information is available regarding the impact of the PGPR mechanism and molecules on metabolic pathways in root characteristics. Consequently, this review will concentrate on elucidating the PGPR mechanism and identifying the essential molecules that exert influence on root-microbe interactions.