Organic fertilizer application in agricultural land is known to improve soil microbial processes, fertility, and yield. In particular, the changes in soil chemical composition due to multi-year application of organic fertilizers are thought to alter the microbial community. Here, the effects of organic fertilization with oil-cake amendments (OC) on soil bacterial diversity, community profile, and enzyme activity were evaluated and compared to those amended with chemical fertilizer (NPK).
View Article and Find Full Text PDFBackground: Rice is colonized by plant growth promoting bacteria such as Methylobacterium leading to mutually beneficial plant-microbe interactions. As modulators of the rice developmental process, Methylobacterium influences seed germination, growth, health, and development. However, little is known about the complex molecular responsive mechanisms modulating microbe-driven rice development.
View Article and Find Full Text PDFPathogenesis-related (PR) signaling plays multiple roles in plant development under abiotic and biotic stress conditions and is regulated by a plethora of plant physiological as well as external factors. Here, our study was conducted to evaluate the role of an ACC deaminase-producing endophytic bacteria in regulating ethylene-induced PR signaling in red pepper plants under salt stress. We also evaluated the efficiency of the bacteria in down-regulating the PR signaling for efficient colonization and persistence in the plant endosphere.
View Article and Find Full Text PDFis a plant-growth-promoting bacterium capable of colonizing and promoting growth in numerous crops of agronomic and horticultural significance. The objective of the present study is to develop CW903- flocculating cells and to test their performance in promoting the growth of red pepper plants grown under salt stress. The flocculating CW903-S recorded 12.
View Article and Find Full Text PDFThe omics-based studies are important for identifying characteristic proteins in plants to elucidate the mechanism of ACC deaminase producing bacteria-mediated salt tolerance. This study evaluates the changes in the proteome of rice inoculated with ACC deaminase producing bacteria under salt-stress conditions. Salt stress resulted in a significant decrease in photosynthetic pigments, whereas inoculation of Methylobacterium oryzae CBMB20 had significantly increased pigment contents under normal and salt-stress conditions.
View Article and Find Full Text PDFSalinity induces myriad of physiological and biochemical perturbations in plants and its amelioration can be attained by the use of potential bacterial synthetic communities. The use of microbial consortia in contrast to single bacterial inoculation can additively enhance stress tolerance and productivity of agricultural crops. In this study, co-inoculation of Pseudomonas koreensis S2CB45 and Microbacterium hydrothermale IC37-36 isolated from arbuscular mycorrhizal fungi (AMF) spore and rice seed endosphere, respectively, were used to evaluate the physiological and biochemical effects on red pepper at two salt concentrations (75Â mM and 150Â mM).
View Article and Find Full Text PDFThe rapid rise in global temperature has adverse effects on rice productivity. The lack of eminent resources for heat stress alleviation is threatening the agricultural sector. Heat stress alleviation by endophytic plant growth-promoting bacteria (PGPB) can be a sustainable and eco-friendly approach.
View Article and Find Full Text PDFNat Rev Microbiol
November 2020
Healthy plants host diverse but taxonomically structured communities of microorganisms, the plant microbiota, that colonize every accessible plant tissue. Plant-associated microbiomes confer fitness advantages to the plant host, including growth promotion, nutrient uptake, stress tolerance and resistance to pathogens. In this Review, we explore how plant microbiome research has unravelled the complex network of genetic, biochemical, physical and metabolic interactions among the plant, the associated microbial communities and the environment.
View Article and Find Full Text PDFMealybugs (Hemiptera: Coccomorpha: Pseudococcidae) harbour diverse microbial symbionts that play essential roles in host physiology, ecology, and evolution. In this study we aimed to reveal microbial communities associated with two different mealybugs, papaya mealybug () and two-tailed mealybug () collected from the same host plant. Comparative analysis of microbial communities associated with these mealybugs revealed differences that appear to stem from phylogenetic associations and different nutritional requirements.
View Article and Find Full Text PDFHeat stress induces secondary metabolic changes in plants, channeling photosynthetic carbon and energy, away from primary metabolic processes, including, growth. Use of ACC (1-aminocyclopropane-1-carboxylate) deaminase containing plant growth promoting bacteria (PGPB) in conferring heat resistance in plants and the role of PGPB, in altering net carbon assimilation, constitutive and stress volatile emissions has not been studied yet. We exposed leaves of Eucalyptus grandis inoculated and non-inoculated with PGPB Brevibacterium linens RS16 to two levels of heat stress (37 °C and 41 °C for 5 min) and quantified temporal changes in foliage photosynthetic characteristics and volatile emission rates at 0.
View Article and Find Full Text PDFThe use of plant growth promoting bacteria as bioinoculant to alleviate salt stress is a sustainable and eco-friendly approach in agriculture. However, the maintenance of the bacterial population in the soil for longer period is a major concern. In the present study, chitosan-immobilized aggregated CBMB20 was used as a bioinoculant to improve tomato plant ( Mill.
View Article and Find Full Text PDFMethyl jasmonate (MeJA) is widely used as a model chemical to study hypersensitive responses to biotic stress impacts in plants. Elevated levels of methyl jasmonate induce jasmonate-dependent defense responses, associated with a decline in primary metabolism and enhancement of secondary metabolism of plants. However, there is no information of how stress resistance of plants, and accordingly the sensitivity to exogenous MeJA can be decreased by endophytic plant growth promoting rhizobacteria (PGPR) harboring ACC (1-aminocyclopropane-1-carboxylate) deaminase.
View Article and Find Full Text PDFSoil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C and C plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (), stomatal conductance (), transpiration rate (), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated plants.
View Article and Find Full Text PDFInoculation of endophytic Methylobacterium oryzae CBMB20 in salt-stressed rice plants improves photosynthesis and reduces stress volatile emissions due to mellowing of ethylene-dependent responses and activating vacuolar H-ATPase. The objective of this study was to analyze the impact of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing Methylobacterium oryzae CBMB20 in acclimation of plant to salt stress by controlling photosynthetic characteristics and volatile emission in salt-sensitive (IR29) and moderately salt-resistant (FL478) rice (Oryza sativa L.) cultivars.
View Article and Find Full Text PDFSoils amended for long-term with high levels of compost demonstrated greater abundance of bacterial members of the phylum Bacteroidetes whereas a decreasing trend in the relative abundance of phylum Acidobacteria was noted with increasing levels of compost. Metabolic profiles predicted by PICRUSt demonstrated differences in functional responses of the bacterial community according to the treatments. Soils amended with lower compost levels were characterized by abundance of genes encoding enzymes contributing to membrane transport and cell growth whereas genes encoding enzymes related to protein folding and transcription were enriched in soils amended with high levels of compost.
View Article and Find Full Text PDFSolitary inoculation of bacteria has been studied widely for plant growth development and amelioration of salinity stress but co-inoculation of bacteria for salt stress amelioration in red pepper plants has been less studied till date. Here, we investigated the co-inoculation effect of Pseudomonas frederiksbergensis OB139 and Pseudomonas vancouverensis OB155 in red pepper plant growth characteristics, plant photosynthesis pigments, ethylene emission, and antioxidant properties under 0, 50, 100 and 150 mM salt stress and compared them with non-inoculated control and single inoculation of each isolate. Results showed increasing concentrations of salinity stress arrested the normal plant growth, increased the stress ethylene levels, disrupted the photosynthetic parameters and also influenced the antioxidant enzymatic activities in non-inoculated control plants.
View Article and Find Full Text PDFInvestigating the bacterial diversity and their metabolic capabilities are crucial for interpreting ecological patterns in desert environment, and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physico-chemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrates a desert environment (Thar Desert, India) which face hot arid climate with very little rainfall and extreme temperatures.
View Article and Find Full Text PDFSoil salinity is one of the major limitations that affects both plant and its soil environment, leading to reduced agricultural production. Evaluation of stress severity by plant physical and biochemical characteristics is an established way to study plant-salt stress interaction, but the halotolerant properties of plant growth promoting bacteria (PGPB) along with plant growth promotion is less studied till date. The aim of the present study was to elucidate the strategy, used by ACC deaminase-containing halotolerant Brevibacterium linens RS16 to confer salt stress tolerance in moderately salt-tolerant (FL478) and salt-sensitive (IR29) rice (Oryza sativa L.
View Article and Find Full Text PDFThe emission of volatiles in response to salt stress in rice cultivars has not been studied much to date. Studies addressing the regulation of stress induced volatile emission by halotolerant plant growth promoting bacteria containing ACC (1-aminocyclopropane-1-carboxylate) deaminase are also limited. The objective of the present study was to investigate the salt alleviation potential of bacteria by regulating photosynthetic characteristics and volatile emissions in rice cultivars, and to compare the effects of the bacteria inoculation and salt responses between two rice genotypes.
View Article and Find Full Text PDFThe pollution of agricultural soils by the heavy metals affects the productivity of the land and has an impact on the quality of the surrounding ecosystems. This study investigated the bacterial community structure in the heavy metal contaminated sites along a smelter and a distantly located paddy field to elucidate the factors that are related to the alterations of the bacterial communities under the conditions of heavy metal pollution. Among the study sites, the bacterial communities in the soil did not show any significant differences in their richness and diversity.
View Article and Find Full Text PDFJ Microbiol Biotechnol
June 2018
Knowledge about the gut bacterial communities associated with insects is essential to understand their roles in the physiology of the host. In the present study, the gut bacterial communities of a laboratory-reared insecticide-susceptible (IS), and a field-collected insecticide-resistant (IR) population of a major rice pest, the brown planthopper , were evaluated. The deep-sequencing analysis of the V3 hypervariable region of the 16S rRNA gene was performed using Illumina and the sequence data were processed using QIIME.
View Article and Find Full Text PDFArbuscular mycorrhizal fungi (AMF) are well-known for their ability to improve plant growth and help plants withstand abiotic stress conditions. Unlike other fungi and bacteria, AMF cannot be stored, as they are obligate biotrophs. Long-term preservation of AMF spores is challenging and may lead to the loss of viability and efficiency.
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