Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability—A Review

Abstract

Plant growth promoting rhizobacteria (PGPR) shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism) of the PGPR for plant growth and the role of the PGPR as biofertilizer-thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

Microbial Endophytes that Live within the Seeds of Two Tomato Hybrids Cultivated in Argentina

“…Such technologies use as their main source the organisms identified within the bacterial communities that are associated with plants, known as the microbiome, to select organisms or groups of organisms to promote plant growth and/or protect plants against stresses, including pathogens [6,7]. In recent years, tens of thousands of microorganisms associated with plants that promote the growth or health of plants have been as their effect on the community structure, particularly that of those microbes with the potential to promote growth (PGPB-plant growth promoting bacteria) and/or control plant pathogens.…”

Screening of efficient rhizobacteria associated with cauliflower (Brassica oleraceavar. botrytis L.) for plant growth promoting traits

“…Numerous soil bacteria which flourish in plant rhizosphere stimulate plant growth by a plethora of mechanisms and are collec-tively known as plant growth promoting rhizobacteria (PGPR). The direct mechanisms include atmospheric nitrogen fixation, phosphate solubilization, siderophore production and secretion of plant growth promoting hormones whereas; the indirect mechanisms include biological control of phytopathogens/deleterious microbes through antibiotic production, lytic enzymes, siderophore and HCN secretion (Vejan et al, 2016). These mechanisms remarkably improve plant health and promote growth in terms of increase in seedling emergence, vigour index and crop yield (Gholami et al, 2009).…”

Drought stress mitigation in Vigna radiata by the application of root-nodulating bacteria

“…Plant growth promoting bacteria are a heterogeneous group of bacteria that can be found in the rhizosphere, at root surfaces and in association with roots, which facilitates the establishment of diverse interaction mechanisms responsible for promoting the quality of plant growth directly and/or indirectly. In the last few decades, a large array of bacteria including species of Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Arthrobacter, Burkholderia, Rhizobium, Flavobacteriaum, Bacillus and Serratia have been reported to enhance plant growth (1,2).…”