Assistant Professor, Institute of Environment and Sustainable Development, Banaras Hindu University
Development of climate resilient beneficial soil microbes for enhancing plant productivity
The crop productivity is subjected to number of stresses and potential yields are seldom achieved with stress. The present challenges like global climate change, water and soil pollution, less water availability, urbanization etc. adds up to the situation Plants are associated with complex microbial population, which are known to promote plant growth and stress tolerance, support plant nutrition and antagonize plant pathogens. The integration of beneficial plant-microbe and microbial interactions might represent a promising solution to improve agricultural production under stressful environments with continuous global climate change. Presently I am engaged in evaluation of plant growth promoting rhizobacteria from stress affected areas like those of salinity and drought. As a long term goal I want to develop some microbial cultures which will be helpful in mitigating the negative impacts of salinity and drought in plants and give a productive yield under stressful environment without any input from synthetic chemistry making agriculture more sustainable and the overall environment free of toxicants and pollutants coming from application of synthetic chemicals like fertilizers and pesticides for enhancing crop productivity. Apart from degrading the environment these applied chemicals also produce biodiversity loss owing to their unknown effects on non-target organisms at the place of application.
Abstract: To feed all of the world's people, it is necessary to sustainably increase agricultural productivity. One way to do this is through the increased use of plant growth-promoting bacteria; recently, scientists have developed a more profound understanding of the mechanisms employed by these bacteria to facilitate plant growth. Here, it is argued that the ability of plant growth-promoting bacteria that produce 1-aminocyclopropane-1-carboxylate (ACC) deaminase to lower plant ethylene levels, often a result of various stresses, is a key component in the efficacious functioning of these bacteria. The optimal functioning of these bacteria includes the synergistic interaction between ACC deaminase and both plant and bacterial auxin, indole-3-acetic acid (IAA). These bacteria not only directly promote plant growth, they also protect plants against flooding, drought, salt, flower wilting, metals, organic contaminants, and both bacterial and fungal pathogens. While a considerable amount of both basic and applied work remains to be done before ACC deaminase-producing plant growth-promoting bacteria become a mainstay of plant agriculture, the evidence indicates that with the expected shift from chemicals to soil bacteria, the world is on the verge of a major paradigm shift in plant agriculture.
Pub.: 08 Oct '13, Pinned: 26 Oct '17
Abstract: The aims of this study were, to analyze in vitro phosphate solubilization activity of six native peanut bacteria and to determine the effect of single and mixed inoculation of these bacteria on peanut and maize plants. Ability to produce organic acids and cofactor PQQ, to solubilize FePO4 and AlPO4 and phosphatase activity were analyzed. Also, the ability to solubilize phosphate under abiotic stress and in the presence of pesticides of the selected bacteria was determined. The effect of single and mixed bacterial inocula was analyzed on seed germination, maize plant growth and in a crop rotation plant assay with peanut and maize. The six strains produced gluconic acid and five released cofactor PQQ into the medium. All bacteria showed ability to solubilize phosphate from FePO4 and AlPO4 and phosphatase activity. The ability of the bacteria to solubilize tricalcium phosphate under abiotic stress and in presence of pesticides indicated encouraging results. Bacterial inoculation on peanut and maize increased seed germination, plant́s growth and P content.
Pub.: 21 Mar '17, Pinned: 26 Oct '17
Abstract: Drought is one of the major constraints on agricultural productivity worldwide and is likely to further increase. Several adaptations and mitigation strategies are required to cope with drought stress. Plant growth promoting rhizobacteria (PGPR) could play a significant role in alleviation of drought stress in plants. These beneficial microorganisms colonize the rhizosphere/endo-rhizosphere of plants and impart drought tolerance by producing exopolysaccharides (EPS), phytohormones, 1-aminocyclopropane- 1-carboxylate (ACC) deaminase, volatile compounds, inducing accumulation of osmolytes, antioxidants, upregulation or down regulation of stress responsive genes and alteration in root morphology in acquisition of drought tolerance. The term Induced Systemic Tolerance (IST) was coined for physical and chemical changes induced by microorganisms in plants which results in enhanced tolerance to drought stresses. In the present review we elaborate on the role of PGPR in helping plants to cope with drought stress.
Pub.: 10 Feb '16, Pinned: 26 Oct '17
Abstract: Plant-growth-promoting rhizobacteria (PGPR) are associated with plant roots and augment plant productivity and immunity; however, recent work by several groups shows that PGPR also elicit so-called 'induced systemic tolerance' to salt and drought. As we discuss here, PGPR might also increase nutrient uptake from soils, thus reducing the need for fertilizers and preventing the accumulation of nitrates and phosphates in agricultural soils. A reduction in fertilizer use would lessen the effects of water contamination from fertilizer run-off and lead to savings for farmers.
Pub.: 06 Dec '08, Pinned: 26 Oct '17