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The domestication process progressively differentiated wild relatives from modern cultivars, thus impacting plant-associated microorganisms. Endophytic bacterial communities play vital roles in plant growth, development, and health, which contribute to the crop's sustainable development. However, how plant domestication impacts endophytic bacterial communities and relevant root exudates in wheat remains unclear. First, we have observed that the domestication process increased the root endophytic microbial community diversity of wheat while decreasing functional diversity. Second, domestication decreased the endophytic bacterial co-occurrence network stability, and it did significantly alter the abundances of core microorganisms or potential probiotics. Third, untargeted LC-MS metabolomics revealed that domestication significantly altered the metabolite profiles, and the abundances of various root exudates released were significantly correlated with keystone taxa including the Chryseobacterium, Massilia, and Lechevalieria. Moreover, we found that root exudates, especially L-tyrosine promote the growth of plant-beneficial bacteria, such as Chryseobacterium. Additionally, with L-tyrosine and Chryseobacterium colonized in the roots, the growth of wild wheat's roots was significantly promoted, while no notable effect could be found in the domesticated cultivars. Overall, this study suggested that wild wheat as a key germplasm material, and its native endophytic microbes may serve as a resource for engineering crop microbiomes to improve the morphological and physiological traits of crops in widely distributed poor soils.
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BACKGROUND: Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55. RESULT: At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease. CONCLUSION: This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial.
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Agrobacterium tumefaciens , Tumores de Planta , Agrobacterium tumefaciens/genética , Enfermedades de las Plantas/microbiología , BacteriasRESUMEN
MAIN CONCLUSION: In this review, we have discussed the untapped potential of orchid endophytic bacteria as a valuable reservoir of bioactive metabolites, offering significant contributions to plant growth promotion and disease protection in the context of sustainable agriculture. Orchidaceae is one of the broadest and most diverse flowering plant families on Earth. Although the relationship between orchids and fungi is well documented, bacterial endophytes have recently gained attention for their roles in host development, vigor, and as sources of novel bioactive compounds. These endophytes establish mutualistic relationships with orchids, influencing plant growth, mineral solubilization, nitrogen fixation, and protection from environmental stress and phytopathogens. Current research on orchid-associated bacterial endophytes is limited, presenting significant opportunities to discover new species or genetic variants that improve host fitness and stress tolerance. The potential for extracting bioactive compounds from these bacteria is considerable, and optimization strategies for their sustainable production could significantly enhance their commercial utility. This review discusses the methods used in isolating and identifying endophytic bacteria from orchids, their diversity and significance in promoting orchid growth, and the production of bioactive compounds, with an emphasis on their potential applications in sustainable agriculture and other sectors.
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Bacterias , Endófitos , Orchidaceae , Simbiosis , Endófitos/fisiología , Endófitos/metabolismo , Orchidaceae/microbiología , Orchidaceae/crecimiento & desarrollo , Orchidaceae/metabolismo , Bacterias/metabolismo , Bacterias/genética , Enfermedades de las Plantas/microbiología , Desarrollo de la PlantaRESUMEN
There is an enormous diversity of life forms present in the extremely intricate marine environment. The growth and development of seaweeds in this particular environment are controlled by the bacteria that settle on their surfaces and generate a diverse range of inorganic and organic chemicals. The purpose of this work was to identify epiphytic and endophytic bacterial populations associated with ten common marine macroalgae from various areas along the Mediterranean Sea coast in Alexandria. This was done to target their distribution and possible functional aspects. Examine the effects of the algal habitat on the counting and phenotypic characterization of bacteria, which involves grouping bacteria based on characteristics such as shape, colour, mucoid nature, type of Gram stain, and their ability to generate spores. Furthermore, studying the physiological traits of the isolates under exploration provides insight into the optimum environmental circumstances for bacteria associated with the formation of algae. The majority of the bacterial isolates exhibited a wide range of enzyme activities, with cellulase, alginase, and caseinase being the most prevalent, according to the data. Nevertheless, 26% of the isolates displayed amylolytic activity, while certain isolates from Miami, Eastern Harbor, and Montaza lacked catalase activity. Geographical variations with the addition of algal extract may impact on the enumeration of the bacterial population, and this might have a relationship with host phylogeny. The most significant observation was that endophytic bacteria associated with green algae increased in all sites, while those associated with red algae increased in Abu Qir and Miami sites and decreased in Eastern Harbor. At the species level, the addition of algal extract led to a ninefold increase in the estimated number of epiphytic bacteria for Cladophora pellucida in Montaza. Notably, after adding algal extract, the number of presented endophytic bacteria associated with Codium sp. increased in Abu Qir while decreasing with the same species in Montaza. In addition to having the most different varieties of algae, Abu Qir has the most different bacterial isolates.
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Bacterias , Endófitos , Filogenia , ARN Ribosómico 16S , Algas Marinas , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/genética , Egipto , Algas Marinas/microbiología , Endófitos/clasificación , Endófitos/aislamiento & purificación , Endófitos/genética , Endófitos/fisiología , Mar Mediterráneo , ARN Ribosómico 16S/genética , Biodiversidad , Agua de Mar/microbiología , ADN Bacteriano/genética , EcosistemaRESUMEN
BACKGROUND: Rhizosphere bacterial community and endophytes are now known to influence plant health and response to environmental stress. Very few studies have reported the diversity of endophytic bacterial communities of Vanilla planifolia and their potential roles in promoting plant growth or contributing to aromatic quality. RESULTS: In this study, the composition and diversity of the Vanilla rhizosphere bacterial community were explored by analyzing rhizosphere soil and root tissue samples as well as green pods of three accessions of Vanilla planifolia grown on different types of substrates (compost and leaf litter). In addition, the endophytic bacterial diversity of roots and green pods as well as the evolution of endophytic bacteria after the curing process of vanilla green pods were analyzed based on a metabarcoding approach. The results showed that bacterial species richness and diversity were higher in the compost. The analysis of the soil bacterial composition displayed that Halomonas, Pseudoalteromonas, Enterobacter and Bradyrhizobium were the most abundant genera. Moreover, the results indicated that the soil bacterial community structure was linked to the host plant genotype. Regarding the roots endophytic bacteria composition, the genera Halomonas, Pseudoalteromonas, Bacillus and Carboxydocella genera were present in all samples, independently from the substrate nature. Several genera including Bacillus, Bradyrhizobium, Burkholderia and Halomonas were transmitted internally from the roots to the green pods. The curing process reduced the bacterial richness and bacterial diversity associated with the green pods. Halomonas, Pseudoalteromonas, Bacillus, and Carboxydocella are the dominant genera in the pods after the curing process. CONCLUSIONS: This study provides an overview of changes of the bacterial communities dynamics especially endophytic in the roots and the green pods. It highlighted bacterial genera (Halomonas, Pseudoalteromonas, Bacillus, and Carboxydocella) potentially implicated in the formation of aroma compounds of vanilla beans.
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Bacterias , Biodiversidad , Endófitos , Raíces de Plantas , Rizosfera , Microbiología del Suelo , Vanilla , Endófitos/clasificación , Endófitos/genética , Endófitos/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Raíces de Plantas/microbiología , Vanilla/microbiología , ARN Ribosómico 16S/genética , Filogenia , Microbiota/genética , ADN Bacteriano/genéticaRESUMEN
Bacterial wilt of tomato caused by Ralstonia solanacearum is a critical soilborne disease that drastically reduces yield. In the current study, an endophytic strain NEAU-CP5 with strong antagonistic activity against R. solanacearum was isolated from tomato seeds and characterized. The strain was identified as Bacillus velezensis based on 16S rRNA gene and whole genome sequence analysis. NEAU-CP5 can secrete amylase, protease, and cellulase, and also produce known antibacterial metabolites, including cyclo (leucylprolyl), cyclo (phenylalanyl-prolyl), cyclo (Pro-Gly), 3-benzyl-2,5-piperazinedione, pentadecanoic acid, eicosane, 2-methyoic acid, isovaleric acid, dibuty phthalate, and esters of fatty acids (HFDU), which may be responsible for its strong antibacterial activity. Fourteen gene clusters associated with antibacterial properties were also identified in the whole genome sequence of NEAU-CP5. Pot experiment demonstrated that the application of 108 CFU/mL NEAU-CP5 on tomato plants significantly reduced the incidence of tomato bacterial wilt by 68.36 ± 1.67 %. NEAU-CP5 also increased the activity of defense-related enzymes (CAT, POD, PPO, SOD, and PAL) in tomato plants. This is the first report of an effective control of bacterial wilt on tomato plants by B. velezensis and highlights the potential of NEAU-CP5 as a potential biocontrol agent for the management of tomato bacterial wilt.
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Bacillus , Filogenia , Enfermedades de las Plantas , ARN Ribosómico 16S , Ralstonia solanacearum , Semillas , Solanum lycopersicum , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/microbiología , Ralstonia solanacearum/genética , Bacillus/aislamiento & purificación , Bacillus/genética , Bacillus/metabolismo , Bacillus/clasificación , Semillas/microbiología , ARN Ribosómico 16S/genética , Antibacterianos/farmacología , Antibacterianos/metabolismo , Endófitos/aislamiento & purificación , Endófitos/genética , Endófitos/metabolismo , Genoma Bacteriano , Secuenciación Completa del Genoma , Antibiosis , Familia de Multigenes , Amilasas/metabolismo , Amilasas/genética , ADN Bacteriano/genéticaRESUMEN
Nitrous oxide (N2 O) is a potent greenhouse gas and causes stratospheric ozone depletion. While the emissions of N2 O from soil are widely recognized, recent research has shown that terrestrial plants may also emit N2 O from their leaves under controlled laboratory conditions. However, it is unclear whether foliar N2 O emissions are universal across varying plant taxa, what the global significance of foliar N2 O emissions is, and how the foliage produces N2 O in situ. Here we investigated the abilities of 25 common plant taxa, including trees, shrubs and herbs, to emit N2 O under in situ conditions. Using 15 N isotopic labeling, we demonstrated that the foliage-emitted N2 O was predominantly derived from nitrate. Moreover, by selectively injecting biocide in conjunction with the isolating and back-inoculating of endophytes, we demonstrated that the foliar N2 O emissions were driven by endophytic bacteria. The seasonal N2 O emission rates ranged from 3.2 to 9.2 ng N2 O-N g-1 dried foliage h-1 . Extrapolating these emission rates to global foliar biomass and plant N uptake, we estimated global foliar N2 O emission to be 1.21 and 1.01 Tg N2 O-N year-1 , respectively. These estimates account for 6%-7% of the current global annual N2 O emission of 17 Tg N2 O-N year-1 , indicating that in situ foliar N2 O emission is a universal process for terrestrial plants and contributes significantly to the global N2 O inventory. This finding highlights the importance of measuring foliar N2 O emissions in future studies to enable the accurate assigning of mechanisms and the development of effective mitigation.
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Gases de Efecto Invernadero , Plantas , Suelo , Atmósfera , Biomasa , Óxido Nitroso/análisisRESUMEN
Cistanche deserticola is a precious Chinese medicinal material with extremely high health care and medicinal value. In recent years, the frequent occurrence of stem rot has led to reduced or even no harvests of C. deserticola. The unstandardized use of farm chemicals in the prevention and control processes has resulted in excessive chemical residues, threatening the fragile desert ecological environment. Therefore, it is urgent to explore safe and efficient prevention and control technologies. Biocontrol agents, with the advantages of safety and environment-friendliness, would be an important idea. The isolation, screening and identification of pathogens and antagonistic endophytic bacteria are always the primary basis. In this study, three novel pathogens causing C. deserticola stem rot were isolated, identified and pathogenicity tested, namely Fusarium solani CPF1, F. proliferatum CPF2, and F. oxysporum CPF3. For the first time, the endophytic bacteria in C. deserticola were isolated and identified, of which 37 strains were obtained. Through dual culture assay, evaluation experiment and tissue culture verification, a biocontrol candidate strain Bacillus atrophaeus CE6 with outstanding control effect on the stem rot was screened out. In the tissue culture system, CE6 showed excellent control effect against F. solani and F. oxysporum, with the control efficacies reaching 97.2% and 95.8%, respectively, indicating its great potential for application in the production. This study is of great significance for the biocontrol of plant stem rot and improvement of the yield and quality of C. deserticola.
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Cistanche , Bacterias/genética , Ambiente , Granjas , Tallos de la PlantaRESUMEN
BACKGROUND: Biotechnology provides a cost-effective way to produce nanomaterials such as silver oxide nanoparticles (Ag2ONPs), which have emerged as versatile entities with diverse applications. This study investigated the ability of endophytic bacteria to biosynthesize Ag2ONPs. RESULTS: A novel endophytic bacterial strain, Neobacillus niacini AUMC-B524, was isolated from Lycium shawii Roem. & Schult leaves and used to synthesize Ag2ONPS extracellularly. Plackett-Burman design and response surface approach was carried out to optimize the biosynthesis of Ag2ONPs (Bio-Ag2ONPs). Comprehensive characterization techniques, including UV-vis spectral analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, dynamic light scattering analysis, Raman microscopy, and energy dispersive X-ray analysis, confirmed the precise composition of the Ag2ONPS. Bio-Ag2ONPs were effective against multidrug-resistant wound pathogens, with minimum inhibitory concentrations (1-25 µg mL-1). Notably, Bio-Ag2ONPs demonstrated no cytotoxic effects on human skin fibroblasts (HSF) in vitro, while effectively suppressing the proliferation of human epidermoid skin carcinoma (A-431) cells, inducing apoptosis and modulating the key apoptotic genes including Bcl-2 associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), Caspase-3 (Cas-3), and guardian of the genome (P53). CONCLUSIONS: These findings highlight the therapeutic potential of Bio-Ag2ONPs synthesized by endophytic N. niacini AUMC-B524, underscoring their antibacterial efficacy, anticancer activity, and biocompatibility, paving the way for novel therapeutic strategies.
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Antibacterianos , Nanopartículas del Metal , Compuestos de Plata , Humanos , Nanopartículas del Metal/química , Compuestos de Plata/farmacología , Compuestos de Plata/química , Antibacterianos/farmacología , Antibacterianos/biosíntesis , Pruebas de Sensibilidad Microbiana , Bacillaceae/metabolismo , Óxidos/farmacología , Óxidos/química , Fibroblastos/efectos de los fármacos , Apoptosis/efectos de los fármacosRESUMEN
Sphagnum mosses are keystone plant species in the peatland ecosystems that play a crucial role in the formation of peat, which shelters a broad diversity of endophytic bacteria with important ecological functions. In particular, methanotrophic and nitrogen-fixing endophytic bacteria benefit Sphagnum moss hosts by providing both carbon and nitrogen. However, the composition and abundance of endophytic bacteria from different species of Sphagnum moss in peatlands of different nutrient statuses and their drivers remain unclear. This study used 16S rRNA gene amplicon sequencing to examine endophytic bacterial communities in Sphagnum mosses and measured the activity of methanotrophic microbial by the 13C-CH4 oxidation rate. According to the results, the endophytic bacterial community structure varied among Sphagnum moss species and Sphagnum capillifolium had the highest endophytic bacterial alpha diversity. Moreover, chlorophyll, phenol oxidase, carbon contents, and water retention capacity strongly shaped the communities of endophytic bacteria. Finally, Sphagnum palustre in Hani (SP) had a higher methane oxidation rate than S. palustre in Taishanmiao. This result is associated with the higher average relative abundance of Methyloferula an obligate methanotroph in SP. In summary, this work highlights the effects of Sphagnum moss characteristics on the endophytic bacteriome. The endophytic bacteriome is important for Sphagnum moss productivity, as well as for carbon and nitrogen cycles in Sphagnum moss peatlands.
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Ecosistema , Sphagnopsida , ARN Ribosómico 16S/genética , Bacterias/genética , Carbono , Nitrógeno , NutrientesRESUMEN
AIMS: The study aimed to determine the pathogenicity of Fusarium species currently prevalent in tomato fields having history of chemical fungicide applications and determine the bio-efficacy of Bacillus subtilis NBRI-W9 as a potent biological control agent. METHODS AND RESULTS: Fusarium was isolated from surface-sterilized infected tomato plants collected from fields. Pathogenicity of 30 Fusarium isolates was determined by in vitro and in vivo assays. Following Koch's postulates, F. chlamydosporum (FOL7) was identified as a virulent pathogen. The biological control of FOL 7 by B. subtilis NBRI-W9 (W9) and the colonization potential of W9 were established using spontaneous rifampicin-resistant mutants. W9 showed 82% inhibition of FOL7 on a dual-culture plate and colonization levels in tomato plants of â¼5.5, â¼3.3, and â¼2.2 log10 CFU/g in root, stem, and leaf tissue, respectively. Antagonistic activity was shown by scanning electron microscopy (SEM) and cell-wall-degradative enzymes. W9 reduced FOL7 infection in net-house and field experiments by 60% and 41%, respectively. Biochemical investigation, defence enzymes, defence gene expression analysis, SEM, and field studies provide evidence of hyperparasitism and induced resistance as the mode of biological control. The study also demonstrates that the potent biocontrol agent W9, isolated from Piper, can colonize tomato plants, control fungal disease by inducing induced systemic resistance (ISR) and systemic acquired resistance (SAR) simultaneously, and increase crop yield by 21.58% under field conditions. CONCLUSIONS: This study concludes that F. chlamydosporum (NBRI-FOL7) is a potent, fungicide-resistant pathogen causing wilt in tomatoes. NBRI-W9 controlled FOL7 through mycoparasitism and simultaneously activated ISR and SAR in plants, providing an attractive tool for disease control that acts at multiple levels.
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Fungicidas Industriales , Fusarium , Solanum lycopersicum , Bacillus subtilis , Resistencia Sistémica Adquirida de la Planta , Plantas , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiologíaRESUMEN
Mulberry zonate leaf spot disease (MZLSD) is an important fungal disease of mulberry trees, which seriously affects the productivity and quality of mulberry leaves. MZLSD has been widely reported in sericultural production areas in Guangxi, China, in recent years. In this study, the causal agent of MZLSD was isolated from symptomatic samples and identified as Gonatophragmium mori (Acrospermaceae) based on morphological characterization and molecular analyses using nucleotide sequences of the internal transcribed spacer (ITS) and large subunit ribosomal DNA (LSU rDNA). Pathogenicity tests confirmed that G. mori is the pathogen responsible for MZLSD. Furthermore, we isolated antagonistic endophytic bacteria (AEB) from healthy mulberry leaves. Plate confrontation experiments showed that the lipopeptide crude extracts (LPCE) of three endophytic bacteria can inhibit the growth of G. mori, and the diameter of the antibacterial circle reaches more than 60 mm when their concentration of LPCE is 200 mg/ml. Light microscopy and scanning electron microscopy revealed that LPCE caused drastic changes in mycelial morphology. Fluorescence microscopy and transmission electron microscopy showed that the LPCE-induced apoptosis-like cell death in G. mori hyphae. Finally, based on morphological and molecular features, we identified the three isolates as Bacillus subtilis DS07, B. subtilis DS32, and B. velezensis Q6, respectively. To our knowledge, this is the first time to identify G. mori by combining characterization and molecular analyses, and we provide timely information about the use of biocontrol agents for suppression of G. mori.
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Morus , China , Antibacterianos , ADN Ribosómico , FrutasRESUMEN
Phytoremediation, including bacteria-assisted phytoremediation, presents a promising technology for treating shooting range soils contaminated with toxic metalloids. In this study, a pot experiment was performed using the halophyte Tamarix smyrnensis and soil collected from a shooting range and artificially spiked at two different antimonite (Sb(III)) concentrations (50 mg/kg and 250 mg/kg) with the aim to explore the Sb phytoremediation of the halophyte. The effect of salt (0.3%) and Mn addition (300 ppm) on its remediation capacity was also investigated. Moreover, the root endophytic community of the halophyte was found able to remove Sb(III) and was periodically inoculated to the plants. The consortium application increased the Sb bioavailable fraction in the soil and enhanced the Sb accumulation in root and aerial parts (up to 50% and 55% respectively at high Sb(III) concentration) compared to the uninoculated plants. Moreover, the presence of Mn increased the translocation factor (21% increase for inoculated and 46% increase for uninoculated plants) while lower TF was observed at high Sb concentrations (0,2 and 0,07 was the lowest value at low and high Sb treatments respectively). The addition of salt, Mn and root endophytic bacteria aided the halophyte to cope with elevated Sb concentrations. The total chlorophyll concentration was higher in inoculated plants compared to the uninoculated ones in all treatments, implying the positive effects of endophytic inoculation. The halophyte T. smyrnensis with the aid of endophytic community presents a promising alternative for remediating shooting range soils especially in areas impacted by salinity.
The halophyte T. smyrnensis presents a promising alternative for remediating shooting range soilsThe application of endophytic bacteria improved the Sb phytoremediation capacity of T. smyrnensisThe halophyte T. smyrnensis can be used for Sb phytoextraction in soils impacted by salinity.
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Contaminantes del Suelo , Tamaricaceae , Plantas Tolerantes a la Sal , Biodegradación Ambiental , Bacterias , Cloruro de Sodio/farmacología , Suelo , Contaminantes del Suelo/análisisRESUMEN
Bistorta vivipara is a medicinal plant with a long history, but there are few studies on the effects of its medicinal components and endophytic bacteria on the accumulation of secondary metabolites. Therefore, in this study, non-targeted metabolomics techniques and 16s rDNA techniques were used to study B. vivipara from different regions. A total of 1290 metabolites and 437 differential metabolites were identified from all samples. Among them, flavonoids, isoflavonoids, and benzopyrans are the main medicinal components of B. vivipara; these have potential anticancer, antiviral, and antioxidant properties, as well as potential applications for the treatment of atrial fibrillation. In addition, irigenin, an important medicinal component, was identified for the first time. The endophytic bacterial communities in the root tissues of B. vivipara from different regions were also different in composition and richness. Hierarchical clustering heat map analysis showed that Proteobacteria and Actinobacteriota bacteria significantly affected the accumulation of many medicinal components in the roots of B. vivipara.
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Raíces de Plantas , Polygonaceae , Raíces de Plantas/microbiología , ADN Ribosómico/genética , Polygonaceae/genética , Bacterias/genética , ProteobacteriaRESUMEN
Environmental pollution stands as one of the significant global challenges we face today. Polycyclic aromatic hydrocarbons (PAHs), a class of stubborn organic pollutants, have long been a focal point of bioremediation research. This study aims to explore the impact and mechanisms of graphene oxide (GO) on the phytoremediation effectiveness of PAHs. The results underscore the significant efficacy of GO in accelerating the degradation of PAHs. Additionally, the introduction of GO altered the diversity and community structure of endophytic bacteria within the roots, particularly those genera with potential for PAH degradation. Through LEfSe analysis and correlation studies, we identified specific symbiotic bacteria, such as Mycobacterium, Microbacterium, Flavobacterium, Sphingomonas, Devosia, Bacillus, and Streptomyces, which coexist and interact under the influence of GO, synergistically degrading PAHs. These bacteria may serve as key biological markers in the PAH degradation process. These findings provide new theoretical and practical foundations for the application of nanomaterials in plant-based remediation of polluted soils and showcase the immense potential of plant-microbe interactions in environmental restoration.
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Bacterias , Biodegradación Ambiental , Grafito , Hidrocarburos Policíclicos Aromáticos , Microbiología del Suelo , Contaminantes del Suelo , Grafito/química , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes del Suelo/metabolismo , Bacterias/efectos de los fármacos , Bacterias/metabolismo , Endófitos/metabolismo , Raíces de Plantas/microbiología , Sphingomonas/metabolismo , Plantas/microbiología , Plantas/metabolismo , Mycobacterium/efectos de los fármacos , Mycobacterium/metabolismo , Flavobacterium/efectos de los fármacos , Flavobacterium/metabolismo , Streptomyces/metabolismo , Microbacterium/metabolismoRESUMEN
The traditional way of dealing with plant diseases has been the use of chemical products, but these harm the environment and are incompatible with the global effort for sustainable development. The use of Bacillus and related species in the biological control of plant diseases is a trend in green agriculture. Many studies report the positive effect of these bacteria, but a synthesis is still necessary. So, the objective of this work is to perform a meta-analysis of Bacillus biocontrol potential and identify factors that drive its efficacy. Data were compiled from articles published in journals listed in two of the main scientific databases between 2000 and 2021. Among 6159 articles retrieved, 399 research papers met the inclusion criteria for a systematic review. Overall, Bacilli biocontrol agents reduced disease by 60% compared to control groups. Furthermore, experimental tests with higher concentrations show a strong protective effect, unlike low and single concentration essays. Biocontrol efficacy also increased when used as a protective inoculation rather than therapeutic inoculation. Inoculation directly in the fruit has a greater effect than soil drenching. The size of the effect of Bacillus-based commercial products is lower than the newly tested strains. The findings presented in this study confirm the power of Bacillus-based bioinoculants and provide valuable guidance for practitioners, researchers, and policymakers seeking effective and sustainable solutions in plant disease management.
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Bacillus , Agentes de Control Biológico , Enfermedades de las Plantas , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Control Biológico de Vectores/métodos , Agricultura/métodos , Microbiología del Suelo , Frutas/microbiologíaRESUMEN
The actinobacterium Arthrobacter sp. UMCV2 promotes plant growth through the emission of N,N-dimethylhexadecilamine (DMHDA). The Medicago-Sinorhizobium nodulation has been employed to study symbiotic nitrogen fixation by rhizobia in nodulating Fabaceae. Herein, we isolated three Sinorhizobium medicae strains that were used to induce nodules in Medicago truncatula. The co-inoculation of M. truncatula with Arthrobacter sp. strain UMCV2 produced a higher number of effective nodules than inoculation with only Sinorhizobium strains. Similarly, the exposure of inoculated M. truncatula to DMHDA produced a greater number of effective nodules compared to non-exposed plants. Thus, we conclude that Arthrobacter sp. UMCV2 promotes nodulation, and propose that this effect is produced, at least partly, via DMHDA emission.
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Endophytic bacteria are an important biological control for nematodes. We isolated the nematicidal Bacillus cereus NJSZ-13 from healthy Pinus elliottii trunks. Bioassay experiments showed killing of all tested nematodes by proteins from the NJSZ-13 culture filtrate within 72 h. Degradation of the nematode cuticles was observed, suggesting the action of extracellular bacterial enzymes. The responsible protease was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, ion-exchange chromatography, and SDS-PAGE. The protease had a molecular weight of 28 kDa and optimal activity at 55 °C and pH 9, indicating an alkaline protease. The study suggests the potential for using this B. cereus NJSZ-13 strain protease to prevent pinewood nematode infection.
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Nematodos , Pinus , Animales , Bacillus cereus/metabolismo , Factores de Virulencia , Péptido Hidrolasas/metabolismo , Nematodos/microbiologíaRESUMEN
Due to their non-toxic and non-carcinogenic nature, biopigments have a phenomenal benefit over synthetic pigments, making them a desirable source for human utilization and a potential alternative to traditional synthetic pigments that are hazardous to the environment and public health. Endosymbiotic interactions between mangrove plants and bacteria could provide an alternate source for the synthesis of unique compounds with potent biomedical applications. Pigmented endophytic bacteria were screened from the explants of Avicennia marina, a mangrove plant, and identified as Micrococcus luteus by molecular characterization. The intracellular pigment was successfully extracted using the sonication-assisted solvent extraction method, and screening factors impacting the pigmentation bioprocess were determined using a one-factor-at-a-time approach. The endophyte produced yellow pigment in the liquid medium, with the maximum growth and pigment production recorded in nutrient broth at 37 â and pH 7 after 96 h of incubation, while the maximum accumulation of pigment was observed in the media supplemented with glucose and tryptone as carbon and nitrogen sources, respectively. The extracted crude pigment was further characterized by ultraviolet, followed by Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry. The obtained crude pigment has been evaluated for its antioxidant and anticancer activity by various assays, such as DPPH radical scavenging activity, FRAP assay, superoxide anion and nitric oxide radical scavenging, metal chelating activity, phosphomolybdenum assay, and MTT assay, respectively, at varying concentrations. The results of our study revealed that the yellow pigment produced by the endophyte showed significant dose-dependent antioxidant and anticancer activity.
Asunto(s)
Antioxidantes , Avicennia , Humanos , Micrococcus luteus , Nutrientes , Carbono , EndófitosRESUMEN
Sphingomonas paucimobilis ZJSH1 is an endophytic bacterium isolated from the roots of Dendrobium officinale with the ability to promote plant growth. It was found that the genome of strain ZJSH1 had gene fragment rearrangement compared with the genomes of the other four strains of S. paucimobilis, and the genome was integrated with phage genes. Functional analysis showed that the strain contained colonization-related genes, chemotaxis and invasion. A variety of genes encoding active materials, such as hormones (IAA, SA, ABA and zeaxanthin), phosphate cycle, antioxidant enzymes, and polysaccharides were identified which provide the strain with growth promotion and stress-resistant characteristics. Experiments proved that S. paucimobilis ZJSH1 grew well in media containing 80 g/L sodium chloride, 240 g/L polyethylene glycol and 800 µmol/L Cd2+, indicating its potential for resistance to stresses of salt, drought and cadmium, respectively. S. paucimobilis ZJSH1 is the only endophytic bacterium of this species that has been reported to promote plant growth. The analysis of its genome is conducive to understanding its growth-promoting mechanism and laying a foundation for the development and utilization of this species in the field of agriculture.