Phytoremediation, a cost-effective, eco-friendly alternative to conventional remediation, could expand efforts to remediate arsenic-contaminated soils. As with other pollutants, the plant microbiome may improve phytoremediation outcomes for arsenic-contaminated sites. We used and methods to compare the arsenic resistance mechanisms, synthesis of extracellular polymeric substances (EPS), biofilm formation, and plant growth-promoting abilities of the endophytes sp.
View Article and Find Full Text PDFThe plant microbiome can be used to bolster plant defense against abiotic and biotic stresses. Some strains of endophytes, the microorganisms within plants, can directly inhibit the growth of plant fungal pathogens. A previously isolated endophyte from wild (poplar), WPB of the species , had robust in vitro antifungal activity against pathogen strains that are highly virulent and of concern to Pacific Northwest agriculture: AG-8, 70110023, and var.
View Article and Find Full Text PDFPhosphorus is one of the essential nutrients for plant growth, but it may be relatively unavailable to plants because of its chemistry. In soil, the majority of phosphorus is present in the form of a phosphate, usually as metal complexes making it bound to minerals or organic matter. Therefore, inorganic phosphate solubilization is an important process of plant growth promotion by plant associated bacteria and fungi.
View Article and Find Full Text PDFEndophytes are fungi, bacteria, or yeast symbionts that live in the intercellular spaces or vascular tissues of host plants. Investigations indicate that endophytes isolated from the Salicaceae family ( and ) hosts provide several benefits that promote plant growth, including but not limited to di-nitrogen fixation, plant hormone production, nutrient acquisition, stress tolerance, and defense against phytopathogens. In exchange, the microorganisms receive domicile and photosynthates.
View Article and Find Full Text PDFPlant-associated microbial communities play a central role in the plant response to biotic and abiotic stimuli, improving plant fitness under challenging growing conditions. Many studies have focused on the characterization of changes in abundance and composition of root-associated microbial communities as a consequence of the plant response to abiotic factors such as altered soil nutrients and drought. However, changes in composition in response to abiotic factors are still poorly understood concerning the endophytic community associated to the phyllosphere, the above-ground plant tissues.
View Article and Find Full Text PDFThe positive effects of high atmospheric CO2 concentrations [CO2] decrease over time in most C3 plants because of down-regulation of photosynthesis. A notable exception to this trend is plants hosting N-fixing bacteria. The decrease in photosynthetic capacity associated with an extended exposure to high [CO2] was therefore studied in non-nodulating rice that can establish endophytic interactions.
View Article and Find Full Text PDFIncreased frequency of droughts and degraded edaphic conditions decreases the success of many reforestation efforts in the Pacific Northwest. Microbial endophyte consortia have been demonstrated to contribute to plant growth promotion and protection from abiotic and biotic stresses - specifically drought conditions - across a number of food crops but for limited tree species. Our research aimed to investigate the potential to improve establishment of economically and ecologically important conifers through a series of field trials and simulations.
View Article and Find Full Text PDFEndophytes are symbiotic microbes that live inside host plants. These endophytic symbionts receive photosynthesized carbohydrates from host plants while conferring symbiotic benefits to their host. During photosynthate-fueled respiration, endophytes release CO into the intercellular spaces of their host plants in which they reside.
View Article and Find Full Text PDFWhile plant-microbe symbioses involving root nodules (Rhizobia and Frankia) or the root-soil interface (rhizosphere) have been well studied, the intimate interaction of microbial endophytes with the plant host is a relatively new field of research.[..
View Article and Find Full Text PDFBacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO enrichment and water deficit. Daytime stomatal conductance and stomatal density were lower in inoculated plants compared to controls.
View Article and Find Full Text PDFPlants intimately associate with diverse bacteria. Plant-associated bacteria have ostensibly evolved genes that enable them to adapt to plant environments. However, the identities of such genes are mostly unknown, and their functions are poorly characterized.
View Article and Find Full Text PDFThe plant endosphere contains a diverse group of microbial communities. There is general consensus that these microbial communities make significant contributions to plant health. Both recently adopted genomic approaches and classical microbiology techniques continue to develop the science of plant-microbe interactions.
View Article and Find Full Text PDFEndophytes are microbial symbionts living inside plants and have been extensively researched in recent decades for their functions associated with plant responses to environmental stress. We conducted a meta-analysis of endophyte effects on host plants' growth and fitness in response to three abiotic stress factors: drought, nitrogen deficiency, and excessive salinity. Ninety-four endophyte strains and 42 host plant species from the literature were evaluated in the analysis.
View Article and Find Full Text PDFTrichloroethylene (TCE) is a widespread environmental pollutant common in groundwater plumes associated with industrial manufacturing areas. We had previously isolated and characterized a natural bacterial endophyte, Enterobacter sp. strain PDN3, of poplar trees, that rapidly metabolizes TCE, releasing chloride ion.
View Article and Find Full Text PDFA controlled field study was performed to evaluate the effectiveness of transgenic poplars for phytoremediation. Three hydraulically contained test beds were planted with 12 transgenic poplars, 12 wild type (WT) poplars, or left unplanted, and dosed with equivalent concentrations of trichloroethylene (TCE). Removal of TCE was enhanced in the transgenic tree bed, but not to the extent of the enhanced removal observed in laboratory studies.
View Article and Find Full Text PDFMicrobial communities in the endosphere of Salicaceae plants, poplar () and willow (), have been demonstrated to be important for plant growth promotion, protection from biotic and abiotic stresses, and degradation of toxic compounds. Our study aimed to investigate bio-control activities of Salicaceae endophytes against various soil borne plant pathogens including AG-8, var. , and .
View Article and Find Full Text PDFThe microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings.
View Article and Find Full Text PDFConvergent evolution is common throughout the tree of life, but the molecular mechanisms causing similar phenotypes to appear repeatedly are obscure. Yeasts have arisen in multiple fungal clades, but the genetic causes and consequences of their evolutionary origins are unknown. Here we show that the potential to develop yeast forms arose early in fungal evolution and became dominant independently in multiple clades, most likely via parallel diversification of Zn-cluster transcription factors, a fungal-specific family involved in regulating yeast-filamentous switches.
View Article and Find Full Text PDFTrichloroethylene (TCE), a chlorinated organic solvent, is one of the most common and widespread groundwater contaminants worldwide. Among the group of TCE-degrading aerobic bacteria, Burkholderia cepacia G4 is the best-known representative. This strain requires the addition of specific substrates, including toluene, phenol, and benzene, to induce the enzymes to degrade TCE.
View Article and Find Full Text PDFSustainable production of biomass for bioenergy relies on low-input crop production. Inoculation of bioenergy crops with plant growth-promoting endophytes has the potential to reduce fertilizer inputs through the enhancement of biological nitrogen fixation (BNF). Endophytes isolated from native poplar growing in nutrient-poor conditions were selected for a series of glasshouse and field trials designed to test the overall hypothesis that naturally occurring diazotrophic endophytes impart growth promotion of the host plants.
View Article and Find Full Text PDFJ Basic Microbiol
March 2013
This study was carried out to examine the diversity of 34 isolates collected from 11 species of leguminous trees growing in South Korea. Phylogenetic relationships between these 34 isolates and reference strains of the Azorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobium and Ensifer/Sinorhizobium were analysed by using 16S rRNA gene sequences. Twenty-one isolates were related to Mesorhizobium, four isolates to Rhizobium, and nine isolates to Bradyrhizobium.
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