Pseudomonas fluorescens as a PGPR (Plant growth Promoting Rhizobacterium) and a biocontrol agent: A Review

Abstract PGPR (Plant growth promoting rhizobacteria) involve group of microbes that harbor in the soil around the plant roots called the rhizosphere and positively influence plant and soil health. Pseudomonas fluorescens is the most dominant PGPR known for its diverse metabolic and plant growth-enhancing activities. The diverse metabolic activities of this bacterium makes it most suitable for use as PGPR. This bacterium enhances plant growth via two mechanisms. The first mechanism is a direct mechanism, consisting of production of plant growth regulatory compounds such as auxins and cytokinins, increasing the availability of nutrients, and an indirect mechanism consisting of production of antifungal metabolic products such as siderophores and HCN. This is known as biocontrol activity. Pseudomonas fluorescens both as a PGPR and biocontrol agent, can be effectively used to increase agricultural yield and inhibit the incidence of fungal crop diseases. Pseudomonas fluorescens can also be used as biofertilizer and biopesticide and it can be an alternative to chemical fertilizers and pesticides. Multiple mechanisms of plant growth promotion and biocontrol can be found in single strain of Pseudomonas fluorescens. The practice of use of biofertilizer and biopesticide can reduce the reliance on chemical inputs to soil and help to reduce soil pollution.