Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soi...Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi (AMF) are universal and ubiquitous rhizosphere mi-croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal (HM) contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial bio-technology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.展开更多
Salt-tolerant plant growth-promoting rhizobacteria （PGPR） can play an important role in alleviating soil salinity stress during plant growth and bacterial exopolysaccharide （EPS） can also help to mitigate salinity...Salt-tolerant plant growth-promoting rhizobacteria （PGPR） can play an important role in alleviating soil salinity stress during plant growth and bacterial exopolysaccharide （EPS） can also help to mitigate salinity stress by reducing the content of Na＋ available for plant uptake. In this study, native bacterial strains of wheat rhizosphere in soils of Varanasi, India, were screened to identify the EPS-producing salt-tolerant rhizobacteria with plant growth-promoting traits. The various rhizobacteria strains were isolated and identified using 16S rDNA sequencing. The plant growth-promoting effect of inoculation of seedlings with these bacterial strains was evaluated under soil salinity conditions in a pot experiment. Eleven bacterial strains which initially showed tolerance up to 80 g L-1 NaC1 also exhibited an EPS-producing potential. The results suggested that the isolated bacterial strains demonstrated some of the plant growth-promoting traits such as phosphate solubilizing ability and production of auxin, proline, reducing sugars, and total soluble sugars. Furthermore, the inoculated wheat plants had an increased biomass compared to the unoinoculated plants.展开更多
Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants h...Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants have developed mechanisms through which they recognize the severity of the stress based on the incoming environmental stimuli.To combat the detrimental effects of drought,the plants have evolved various strategies to modulate their physio-hormonal attributes.These strategies that can be modulated by shade and microbes contribute to enhancing tolerance to drought and reducing yield loss.Plant hormones,such as abscisic acid,auxin and ethylene have a major role in the shade-and microbe-associated improvement of drought tolerance through their effects on various metabolic pathways.In this process,the CLAVATA3/EMBRYOSURROUNDING REGION-RELATED 25 peptide has a major role due to its effect on ABA synthesis as shown in our regulatory model.展开更多
文摘Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi (AMF) are universal and ubiquitous rhizosphere mi-croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal (HM) contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial bio-technology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.
基金Supported by the Council of Scientific and Industrial Research,Human Research Development Group,Government of India
文摘Salt-tolerant plant growth-promoting rhizobacteria （PGPR） can play an important role in alleviating soil salinity stress during plant growth and bacterial exopolysaccharide （EPS） can also help to mitigate salinity stress by reducing the content of Na＋ available for plant uptake. In this study, native bacterial strains of wheat rhizosphere in soils of Varanasi, India, were screened to identify the EPS-producing salt-tolerant rhizobacteria with plant growth-promoting traits. The various rhizobacteria strains were isolated and identified using 16S rDNA sequencing. The plant growth-promoting effect of inoculation of seedlings with these bacterial strains was evaluated under soil salinity conditions in a pot experiment. Eleven bacterial strains which initially showed tolerance up to 80 g L-1 NaC1 also exhibited an EPS-producing potential. The results suggested that the isolated bacterial strains demonstrated some of the plant growth-promoting traits such as phosphate solubilizing ability and production of auxin, proline, reducing sugars, and total soluble sugars. Furthermore, the inoculated wheat plants had an increased biomass compared to the unoinoculated plants.
基金This work was supported by the National Research,Development and Innovation Office(grant no.K131638)National Natural Science Foundation of China(grant nos.31871552,31671445)Sichuan Science and Technology Program(grant no.2018HH0108).
文摘Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants have developed mechanisms through which they recognize the severity of the stress based on the incoming environmental stimuli.To combat the detrimental effects of drought,the plants have evolved various strategies to modulate their physio-hormonal attributes.These strategies that can be modulated by shade and microbes contribute to enhancing tolerance to drought and reducing yield loss.Plant hormones,such as abscisic acid,auxin and ethylene have a major role in the shade-and microbe-associated improvement of drought tolerance through their effects on various metabolic pathways.In this process,the CLAVATA3/EMBRYOSURROUNDING REGION-RELATED 25 peptide has a major role due to its effect on ABA synthesis as shown in our regulatory model.
