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The use of microorganisms with the aim of improving nutrients availability for plants is an

important practice (Garnier et al., 2006). During recent decades, the utilization of plant
growth promoting rhizobacteria (PGPR) for manageable horticulture has expanded hugely in

the entire world. Noteworthy increments in development and yield of significant harvests in
light of immunization with PGPR have been over and over-detailed (Figueiredo et al., 2008;

A. Gupta et al., 2000; Júnior et al., 2006). Rhizosphere is a constricted region of soil in
immediate proximity to the root system populated by a large group of beneficial bacteria

termed as plant growth promoting rhizobacteria (PGPR) which critically influence plant

growth. To qualify as a PGPR, the bacterium must be capable of root surface colonization,
compete with other microbiota, survive and reproduce till they are able to express their plant

growth promotion traits also they must endorse plant growth (Mahaffee et al., 1994). There

are two major classes of PGPRs, i.e., extracellular plant growth promoting rhizobacteria
(ePGPR) and intracellular plant growth promoting rhizobacteria (iPGPR) (Gupta et al.,

2015). Typically, the ePGPR able to colonize the rhizosphere or the upper surface of the root
cortex e.g., Agrobacterium, Azotobacter, Arthrobacter, Bacillus, Azospirillum, Burkholderia,

Chromobacterium Micrococcous, Serratia, Pseudomonas etc. (Bhattacharyya et al., 2012). In
case of iPGPR able to frequently exist in the particular nodulated parts of the root cells e.g.

Allorhizobium, Azorhizobium, Bradyrhizobium, Rhizobium, Mesorhizobium etc. (Ahmed et

al., 2010; Glick, 2012) . The scope of process by which soil microscopic organisms
apply a constructive outcome on plant development incorporates alteration of root

advancement, including improvement of mineral sustenance, upgrade of plant resistance to
biotic and abiotic stress and concealment of soil-borne infections (Holguin et al., 1999). Our

point in this article is to join and support the comprehension of common and oversaw
environments alongside the utilization of various mechanisms of action of this biological

system model in the cutting-edge agribusiness framework.
Generally, free-living and nitrogen fixing PGPR able to influence the growth and yield of
various crops and vegetables via direct or indirect mechanisms (Gupta et al., 2000). PGPR

are classified according to their functional activities (Somers et al., 2004) such as:

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