Microbial Consortium of Plant Growth-Promoting Rhizobacteria Improves the Performance of Plants Growing in Stressed Soils: An Overview

Abstract

Soil and associated stress conditions not only influence dwelling microbial populations and soil ecosystems but also affect growth and yield of plants. Major soil stress includes salinity, drought, and metal contamination. Due to burgeoning populations and expanding food demands, it has become imperative to alleviate the stressful soil conditions so that the crop production is increased and, consequently, the food demands are fulfilled. Different strategies are followed to resolve this problem, and one such approach involves exploiting microbial potential for plant's benefit. The multifunctional microscopic life-forms are already known for their applications in industries, medicine, and agricultural field. One of the major attributes of microbes from agronomic point of view is their ability to solubilize difficultly available forms of soil phosphorus. Phosphate-solubilizing microbes are also known to produce enzymes, siderophores, and growth hormones; embellish plant growth and biocontrol activity; and improve soil properties. Such microorganisms possessing attributes, beneficial for plants are termed as plant growth-promoting rhizobacteria (PGPR). There are plentiful reports on bacterialmediated plant growth promotion under nonstressed conditions although fewer reports are available on their effects under stressed condition. The bacterial ability to enhance tolerance of plants in stressed soils and the impact of PGPR consortium (mixture) on different crops are highlighted. The major idea here is to consolidate the fact that PGPR consortium can be used directly in stress-affected soil with an aim to refurbish soil conditions to foster crop productivity in stressed soils.

ACC Deaminase Producing Bacteria With Multifarious Plant Growth Promoting Traits Alleviates Salinity Stress in French Bean (Phaseolus vulgaris) Plants

“…Phosphate solubilization is another important trait of PGPR and the isolates of the current study revealed a significant release of PO 4 3- from insoluble complex TCP. The findings of the current study are in agreement with numerous published literatures reporting solubilization of phosphate by Bacillus, Pseudomonas , and Azotobacter (Ahmad et al, 2008; Bhattacharyya and Jha, 2012; Panwar et al, 2014; Maitra et al, 2015). Besides providing phosphorous to the plants, the PSBs also enhance the plant’s growth by stimulating nitrogen fixation, enhancing availability of trace metals and by formation of plant growth hormones (Kumar et al, 2013).…”

Plant Growth Stimulation by Microbial Consortia

“…To enhance the beneficial functions displayed by these bacteria, the design of bacterial consortia has gained interest as a suitable strategy for sustainable food production. A bacterial consortium generally constitutes two or more compatible bacteria of different species in a synergistic or additive interaction [42][43][44]. In some cases, a mixture of different strains of the same species can exhibit enhanced activities and also be considered a consortium.…”

Synergistic effect ofPseudomonas putidaandBacillus amyloliquefaciensameliorates drought stress in chickpea (Cicer arietinumL.)

“…12 In general, it has been reported by several researchers that inoculation with consortia have better plant growth promotion as compared to individual inoculations because individual strain is supplementing to each other for their beneficial traits. 13,14 We have used 2 well proven PGPR Pseudomonas putida NBRIRA (RA) and Bacillus amyloliquefaciens NBRISN13 (SN13) in our laboratory. 15,16 The strain RA is Gram negative and displayed multiple PGP activities like auxin production, phosphate solubilisation and tolerance to drought and salt stresses.…”