Author(s):

Poonam Gusain and BS Bhandari

Abstract: Sustainability of agricultural production is very important to fulfill the growing demands of food to feed the world increasing population. Use of plant growth-promoting rhizobacteria (PGPR) as efficient biofertilizer seems an ideal tool to mitigate global dependence on hazardous agrichemicals and improve food security. The microbial population colonizing rhizosphere includes bacteria, fungi, actinomycetes, protozoa, and algae. Free-living bacteria associated with rhizosphere, beneficial to plant growth, usually include the cyanobacteria of the genera Allorhizobium, Azorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobium, and Sinorhizobium. Free-living nitrogen fixing bacteria or associative nitrogen fixers belonging to the species Azospirillum, Enterobacter, Klebsiella and Pseudomonas, have been shown to attach to the root and efficiently colonize root surfaces. Generally, plant growth promotion and development can be facilitated in various ways: preventing of the deleterious effects of phytopathogens by synthesizing biogenic chelator compounds such as siderophores, facilitating the production of plant hormones such as auxins, cytokinins, gibberellins, ethylene, antibiotics, volatile metabolites, enzymes, abscisic acid, and solubilization of mineral phosphates and other nutrients have been reported for several PGPR bacterial genera. Hence, this review highlights the key mechanisms employed by PGPR bacteria to facilitate plant growth to increase the health and productivity of cultivated soils.

Pages: 1181-1191  |  1283 Views  596 Downloads

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