Contribution of PGPRs to Plant Growth: A Review

PGPR play an important role in maintaining soil equilibrium. It is a living medium composed mainly of heterotrophic micro-organisms, and is a major reservoir of rhizobacteria. It contains a complex and varied microflora that plays essential roles for the soil ecosystem and higher soil organisms. The methodology used in this study was based on in-depth literature reviews and documentary research. The results obtained showed that basically, PGPRs are defined by three intrinsic characteristics, so they are divided into extracellular (ePGPR) and intracellular (iPGRP). Thanks to their metabolic plasticity, these soil microorganisms are involved in the degradation and immobilization of pollutants brought in by agriculture or industry. In the rhizosphere, in terms of biomass and taxonomic diversity, PGPR are by far the most abundant soil microorganisms. The aim of the study is to analyze the results of research showing the significant influence of PGPR on plant growth, thus contributing to a better understanding of crop nutrition.