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1.
Int J Mol Sci ; 22(4)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578992

RESUMO

In this study, endophytic bacteria belonging to the Bacillus genus were isolated from in vitro bulblets of Leucojum aestivum and their ability to produce Amaryllidaceae alkaloids was studied. Proton Nuclear Magnetic Resonance (1H NMR)-based metabolomics combined with multivariate data analysis was chosen to compare the metabolism of this plant (in vivo bulbs, in vitro bulblets) with those of the endophytic bacteria community. Primary metabolites were quantified by quantitative 1H NMR (qNMR) method. The results showed that tyrosine, one precursor of the Amaryllidaceae alkaloid biosynthesis pathway, was higher in endophytic extract compared to plant extract. In total, 22 compounds were identified including five molecules common to plant and endophyte extracts (tyrosine, isoleucine, valine, fatty acids and tyramine). In addition, endophytic extracts were analyzed using Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS) for the identification of compounds in very low concentrations. Five Amaryllidaceae alkaloids were detected in the extracts of endophytic bacteria. Lycorine, previously detected by 1H NMR, was confirmed with LC-MS analysis. Tazettine, pseudolycorine, acetylpseudolycorine, 1,2-dihydro-chlidanthine were also identified by LC-MS using the positive ionization mode or by GC-MS. In addition, 11 primary metabolites were identified in the endophytic extracts such as tyramine, which was obtained by decarboxylation of tyrosine. Thus, Bacillus sp. isolated from L. aestivum bulblets synthesized some primary and specialized metabolites in common with the L.aestivum plant. These endophytic bacteria are an interesting new approach for producing the Amaryllidaceae alkaloid such as lycorine.


Assuntos
Alcaloides de Amaryllidaceae/metabolismo , Amaryllidaceae/microbiologia , Bacillus/metabolismo , Endófitos/metabolismo , Alcaloides de Amaryllidaceae/análise , Bacillus/química , Bacillus/isolamento & purificação , Cromatografia Líquida , Endófitos/química , Endófitos/isolamento & purificação , Microbiologia Industrial/métodos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Metabolômica
2.
Molecules ; 26(4)2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33567664

RESUMO

As the population ages globally, there seem to be more people with Alzheimer's disease. Unfortunately, there is currently no specific treatment for the disease. At present, Huperzine A (HupA) is one of the best drugs used for the treatment of Alzheimer's disease and has been used in clinical trials for several years in China. HupA was first separated from Huperzia serrata, a traditional medicinal herb that is used to cure fever, contusions, strains, hematuria, schizophrenia, and snakebite for several hundreds of years in China, and has been confirmed to have acetylcholinesterase inhibitory activity. With the very slow growth of H. serrata, resources are becoming too scarce to meet the need for clinical treatment. Some endophytic fungal strains that produce HupA were isolated from H. serrate in previous studies. In this article, the diversity of the endophytic fungal community within H. serrata was observed and the relevance to the production of HupA by the host plant was further analyzed. A total of 1167 strains were obtained from the leaves of H. serrata followed by the stems (1045) and roots (824). The richness as well as diversity of endophytic fungi within the leaf and stem were higher than in the root. The endophytic fungal community was similar within stems as well as in leaves at all taxonomic levels. The 11 genera (Derxomyces, Lophiostoma, Cyphellophora, Devriesia, Serendipita, Kurtzmanomyces, Mycosphaerella, Conoideocrella, Brevicellicium, Piskurozyma, and Trichomerium) were positively correlated with HupA content. The correlation index of Derxomyces with HupA contents displayed the highest value (CI = 0.92), whereas Trichomerium showed the lowest value (CI = 0.02). Through electrospray ionization mass spectrometry (ESI-MS), it was confirmed that the HS7-1 strain could produce HupA and the total alkaloid concentration was 3.7 ug/g. This study will enable us to screen and isolate the strain that can produce HupA and to figure out the correlation between endophytic fungal diversity with HupA content in different plant organs. This can provide new insights into the screening of strains that can produce HupA more effectively.


Assuntos
Alcaloides/biossíntese , Biodiversidade , Endófitos/classificação , Endófitos/metabolismo , Fungos/classificação , Fungos/metabolismo , Huperzia/microbiologia , Endófitos/isolamento & purificação , Endófitos/fisiologia , Fungos/isolamento & purificação , Fungos/fisiologia , Sesquiterpenos
3.
Arch Microbiol ; 202(10): 2779-2789, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32743668

RESUMO

Endophytes are considered one of the most important microbial resources for obtaining biomolecules of therapeutic use. Passiflora incarnata, widely employed by the pharmaceutical industry, shows therapeutic effects on anxiety, nervousness, constipation, dyspepsia and insomnia based on their antioxidant compounds. In this study, from 315 endophytic fungi isolated from P. incarnata leaves, 60 were selected to determinate presence of chemical constituents related with antioxidant activity, based on their production of soluble pigments. The promising fungi were evaluated specifically on their potential to produce phenolic compounds, flavonoids and for antioxidant activity. Five isolates significantly produced flavonoids and phenolic compounds in the ethyl acetate and n-Butanol extracts, also saponins and high antioxidant activity against the DPPH (2.2-diphenyl-1-picrylhydrazyl) free radical. A strain of Aspergillus nidulans var. dentatus (former Emericella dentata) was able to produce tannins as well; its butanolic extract was very similar than the BHT (butylated hydroxytoluene) (94.3% × 94.32%) and Rutin (95.8%) reference substances in the DPPH radical scavenging. Similarly, a Chaetomium strain exhibited 93.6% and 94.7% of antioxidant activity in their ethyl acetate and butanolic fractions, respectively. The chromatographic analysis of the ethyl acetate fraction from the Aspergillus strain revealed the production of orcinol (3.19%). Four-methoxymethylphenol (4.79%), sorbicillin (33.59%) and ergosterol (23.08%) was produced by Trichoderma longibrachiatum and isopropenyl-1,4-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulene were found in two Fusarium oxysporum strains. The phytochemical screening showed that all analyzed fungi were able to produce a kind of secondary metabolite (phenols, flavonoids, tannins and/or saponins). The study shows a great underexplored potential for industrial application of P. incarnata endophytes.


Assuntos
Antioxidantes/análise , Flavonoides/análise , Fungos/isolamento & purificação , Fungos/metabolismo , Passiflora/microbiologia , Fenóis/análise , Compostos de Bifenilo/análise , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/metabolismo , Radicais Livres/análise , Fungos/classificação , Extratos Vegetais/química , Folhas de Planta/microbiologia , Taninos
4.
Arch Microbiol ; 202(10): 2739-2749, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32737540

RESUMO

The signal orchestration between legumes and the rhizobia attribute to symbiotic nitrogen fixation through nodule formation. Root nodules serve as a nutrient-rich reservoir and harbor diverse microbial communities. However, the existence of non-rhizobial endophytes (NRE) and their role inside the root nodules are being explored; there is no evidence on yeast microflora inhabiting nodule niche. This study focused on unraveling the presence of yeast in the root nodules and their possible function in either nodulation or signal exchange. From the root nodules of blackgram, two yeast strains were isolated and identified as Candida glabrata VYP1 and Candida tropicalis VYW1 based on 18S rRNA gene sequencing and phylogeny. These strains possessed plant growth-promoting traits viz., IAA, ACC deaminase, siderophore, ammonia, and polyamine production. The functional capacity of endophytic yeast strains, and their interaction with Rhizobium sp. was further unveiled via profiling volatile organic compounds (VOC). Among the VOCs, α-glucopyranoside and pyrroloquinoline pitches a pivotal role in activating lectin pathways and phosphorous metabolism. Further, lectin pathways are crucial for nodulating bacterium, and our study showed that these endophytic yeasts assist nodulation by Rhizobium sp. via activating the nod factors. The plant growth-promoting traits of NRE yeast strains coupled with their metabolite production, could recruit them as potential drivers in the plant-microbe interaction.


Assuntos
Candida glabrata/isolamento & purificação , Candida tropicalis/isolamento & purificação , Endófitos/isolamento & purificação , Vigna/microbiologia , Compostos Orgânicos Voláteis/análise , Candida glabrata/genética , Candida tropicalis/genética , Carbono-Carbono Liases , Endófitos/classificação , Interações Microbianas , Fixação de Nitrogênio/fisiologia , Filogenia , Desenvolvimento Vegetal , Nodulação , Pirróis/análise , Quinolinas/análise , Rhizobium/fisiologia , Nódulos Radiculares de Plantas/microbiologia , Simbiose/fisiologia
5.
Arch Microbiol ; 202(10): 2771-2778, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32737542

RESUMO

A bacterial strain designated NYYP31T was isolated from the leaves of an annual halophytes, Suaeda corniculata Bunge, collected from the southern edge of the Gurbantunggut desert, north-west China. Strain NYYP31T was Gram-staining negative, strictly aerobic, rod-shaped, non-motile, and non-spore-forming. Growth was observed at 4-42 °C, at pH 5.0-10.0, in the presence of up to 8% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences and coding sequences of 92 protein clusters showed that strain NYYP31T should be assigned to the genus Sphingobacterium. 16S rRNA gene sequence similarity analysis showed that strain NYYP31T was most closely related to the type strain of Sphingobacterium daejeonense (97.9%) and Sphingobacterium lactis (97.7%). The predominant isoprenoid quinone was MK-7. The major fatty acids were identified as iso-C15:0, iso-C17:0 3-OH and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The polar lipids were phosphatidylethanolamine, two unidentified phospholipids, three unidentified lipids, three unidentified amino phospholipids, and two unidentified glycolipids. The genomic DNA G + C content was 36.4 mol%. The average nucleotide identity (ANI) values for strain NYYP31T to the type strains of S. daejeonense and S. lactis were 77.9 and 74.1%, respectively, which were below the cut-off level (95-96%) for species delineation. Based on the above results, strain NYYP31T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium endophyticum sp. nov. is proposed. The type strain is NYYP31T (= CGMCC 1.16979T = NBRC 114258T).


Assuntos
Chenopodiaceae/microbiologia , Plantas Tolerantes a Sal/microbiologia , Sphingobacterium/classificação , Sphingobacterium/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases/genética , China , DNA Bacteriano/genética , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Filogenia , Folhas de Planta/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia do Solo , Sphingobacterium/genética , Vitamina K 2/química
6.
Proc Natl Acad Sci U S A ; 117(32): 19347-19358, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723830

RESUMO

Bacterial intracellular symbiosis (endosymbiosis) is widespread in nature and impacts many biological processes. In holometabolous symbiotic insects, metamorphosis entails a complete and abrupt internal reorganization that creates a constraint for endosymbiont transmission from larvae to adults. To assess how endosymbiosis copes-and potentially evolves-throughout this major host-tissue reorganization, we used the association between the cereal weevil Sitophilus oryzae and the bacterium Sodalis pierantonius as a model system. S. pierantonius are contained inside specialized host cells, the bacteriocytes, that group into an organ, the bacteriome. Cereal weevils require metabolic inputs from their endosymbiont, particularly during adult cuticle synthesis, when endosymbiont load increases dramatically. By combining dual RNA-sequencing analyses and cell imaging, we show that the larval bacteriome dissociates at the onset of metamorphosis and releases bacteriocytes that undergo endosymbiosis-dependent transcriptomic changes affecting cell motility, cell adhesion, and cytoskeleton organization. Remarkably, bacteriocytes turn into spindle cells and migrate along the midgut epithelium, thereby conveying endosymbionts to midgut sites where future mesenteric caeca will develop. Concomitantly, endosymbiont genes encoding a type III secretion system and a flagellum apparatus are transiently up-regulated while endosymbionts infect putative stem cells and enter their nuclei. Infected cells then turn into new differentiated bacteriocytes and form multiple new bacteriomes in adults. These findings show that endosymbiosis reorganization in a holometabolous insect relies on a synchronized host-symbiont molecular and cellular "choreography" and illustrates an adaptive feature that promotes bacteriome multiplication to match increased metabolic requirements in emerging adults.


Assuntos
Enterobacteriaceae/fisiologia , Simbiose , Gorgulhos/crescimento & desenvolvimento , Gorgulhos/microbiologia , Animais , Fenômenos Fisiológicos Bacterianos , Evolução Biológica , Sistema Digestório/microbiologia , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/fisiologia , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Feminino , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Masculino , Metamorfose Biológica , Gorgulhos/fisiologia
7.
Can J Microbiol ; 66(11): 670-677, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32640165

RESUMO

Nonrhizobial root nodule endophytic bacteria are known to have beneficial effects on host plants and are also considered contaminants or opportunists. They grow either individually or as a co-occupant of the root nodules of legumes. In this study, a nonrhizobial endophytic bacterial strain was isolated from the root nodules of the medicinal legume Mucuna utilis var. capitata L.; phenotypic, genotypic, and agricultural characterization was performed using a HiMedia kit and 16S rRNA sequencing. This strain showed tremendous seedling growth potential (30%), compared with the control, as well as a strong antagonistic nature against the plant pathogenic fungus Fusarium udum when plant growth parameters were analyzed. The strain, identified by 16S rRNA as Stenotrophomonas maltophilia, showed a multitude of plant-growth-promoting attributes both direct (IAA, phosphate solubilization) and indirect (ACC deaminase, siderophore) and enhanced the growth of host plant in field trials. This is the first report of the plant-growth-promoting potential of this endophytic bacterium from the nodules of M. utilis var. capitata L.; hence, it has potential for use in various biotechnological applications in various industries.


Assuntos
Endófitos/fisiologia , Mucuna/crescimento & desenvolvimento , Mucuna/microbiologia , Nódulos Radiculares de Plantas/microbiologia , Stenotrophomonas maltophilia/fisiologia , Antibiose , Carbono-Carbono Liases/metabolismo , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Ácidos Indolacéticos/metabolismo , Fosfatos/metabolismo , RNA Ribossômico 16S/genética , Sideróforos/metabolismo , Stenotrophomonas maltophilia/classificação , Stenotrophomonas maltophilia/genética , Stenotrophomonas maltophilia/isolamento & purificação
8.
PLoS One ; 15(6): e0233783, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497087

RESUMO

Managing pests in carrot production is challenging. Endophytic microbes have been demonstrated to improve the health and productivity of many crops, but factors affecting endophyte dynamics in carrot is still not well understood. The goal of this study was to determine how crop management system and carrot genotype interact to affect the composition and potential of endophytes to mitigate disease caused by Alternaria dauci, an important carrot pathogen. Twenty-eight unique isolates were collected from the taproots of nine diverse genotypes of carrot grown in a long-term trial comparing organic and conventional management. Antagonistic activity was quantified using an in vitro assay, and potential for individual isolates to mitigate disease was evaluated in greenhouse trials using two carrot cultivars. Results confirm that carrot taproots are colonized by an abundant and diverse assortment of bacteria and fungi representing at least distinct 13 genera. Soils in the organic system had greater total organic matter, microbial biomass and activity than the conventional system and endophyte composition in taproots grown in this system were more abundant and diverse, and had greater antagonistic activity. Carrot genotype also affected endophyte abundance as well as potential for individual isolates to affect seed germination, seedling growth and tolerance to A. dauci. The benefits of endophytes on carrot growth were greatest when plants were subject to A. dauci stress, highlighting the importance of environmental conditions in the functional role of endophytes. Results of this study provide evidence that endophytes can play an important role in improving carrot performance and mediating resistance to A. dauci, and it may someday be possible to select for these beneficial plant-microbial relationships in carrot breeding programs. Implementing soil-building practices commonly used in organic farming systems has potential to promote these beneficial relationships and improve the health and productivity of carrot crops.


Assuntos
Alternaria/fisiologia , Produção Agrícola/métodos , Daucus carota/genética , Daucus carota/microbiologia , Endófitos/fisiologia , Genótipo , Doenças das Plantas/microbiologia , Proteção de Cultivos/métodos , Daucus carota/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Germinação , Solo/química , Microbiologia do Solo
9.
Arch Microbiol ; 202(7): 1899-1906, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448960

RESUMO

Endophytic bacteria have been reported to have symbiotic, mutualistic, commensalistic or trophobiotic relationships with various plant parts. As part of its adaptation, many endophytic organisms are known to exhibit properties with multiple beneficial effects to the plant system. Even though many bacterial genera have been identified to have endophytic association, isolation of those which were previously demonstrated well for human association is quite interesting. In the study, endophytic bacteria Ceb1 isolated from the rhizome of Curcuma longa was identified by 16S rDNA sequencing as Staphylococcus sp. Further, Ceb1 was observed to have the ability to tolerate drought stress. While screening for the plant growth-promoting traits, Ceb1 was found to be positive for IAA production both under drought-stressed and normal conditions as confirmed by HPLC. The Ceb1 priming with Vigna unguiculata was observed to enhance the growth parameters of the plant. Analysis of Ceb1-treated plants by ICP-MS further showed modulation of both macro- and micronutrients. Upon drought stress induction in Vigna unguiculata, Ceb1 was found to provide synergistic plant growth-promoting effect to the plant along with the supplemented silicate sources. Under the changing agroclimatic conditions, exploring the plant stress-alleviating effects of endophytes is highly significant.


Assuntos
Secas , Desenvolvimento Vegetal , Plantas/microbiologia , Silicatos/farmacologia , Staphylococcus/fisiologia , Curcuma/microbiologia , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Desenvolvimento Vegetal/fisiologia , RNA Ribossômico 16S/genética , Rizoma/microbiologia , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Simbiose , Vigna/fisiologia
10.
Mol Plant Microbe Interact ; 33(7): 876-879, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32223578

RESUMO

Bacillus sp. strain WR11 isolated from the root of wheat (Triticum aestivum L.) possesses abiotic stress alleviating properties and produces several types of enzymes. However, its genomic information is lacking. The study described the complete genome sequence of the bacterium. The size of the genome was 4 202 080 base pairs that consisted of 4 405 genes in total. The G+C content of the circular genome was 43.53% and there were 4 170 coding genes, 114 pseudo genes, 30 ribosome RNAs, 86 tRNAs, and 5 ncRNAs, based on the Prokaryotic Genome Annotation Pipeline (PGAP). Many genes were related to the stress-alleviating properties and 124 genes existed in the CAZy database. The complete genome data of strain WR11 will provide valuable resources for genetic dissection of its plant growth-promoting function and symbiotic interaction with plant.


Assuntos
Bacillus , Genoma Bacteriano , Triticum/microbiologia , Bacillus/genética , Bacillus/isolamento & purificação , Endófitos/genética , Endófitos/isolamento & purificação , Raízes de Plantas/microbiologia
11.
PLoS One ; 15(4): e0232096, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32339210

RESUMO

Endophytic bacteria, which are common in plant tissues, may help to control plant pathogens and enhance plant growth. Camellia oleifera, an oil-producing plant, is widely grown in warm, subtropical, hilly regions in China. However, C. oleifera is strongly negatively affected by C. oleifera anthracnose, which is caused by Colletetrichum fructicola. To find a suitable biocontrol agent for C. oleifera anthracnose, 41 endophytes were isolated from the stems, leaves, and roots of C. oleifera. Bacterial cultures were identified based on analyses of 16S rDNA sequences; most strains belonged to the genus Bacillus. The antagonistic effects of these strains on C. fructicola were tested in vitro. In total, 16 strains inhibited C. fructicola growth, with B. subtilis strain 1-L-29 being the most efficient. Strain 1-L-29 demonstrated antagonistic activity against C. siamense, C. asianum, Fusarium proliferatum, Agaricodochium camellia, and Pseudomonas syringae. In addition, this strain produced indole acetic acid, solubilized phosphate, grew on N-free media, and produced siderophores. To facilitate further microecological studies of this strain, a rifampicin-resistant, green fluorescent protein (GFP)-labeled strain, 1-L-29gfpr, was created using protoplast transformation. This plasmid had good segregational stability. Strain 1-L-29gfpr was re-introduced into C. oleifera and successfully colonized root, stem, and leaf tissues. This strain remained at a stable concentration in the root more than 20 d after inoculation. Fluorescence microscopic analysis showed that strain 1-L-29gfpr thoroughly colonized the root surfaces of C. fructicola as well as the root vascular tissues of Arabidopsis thaliana.


Assuntos
Antibacterianos/metabolismo , Bacillus subtilis/metabolismo , Camellia/crescimento & desenvolvimento , Endófitos/metabolismo , Doenças das Plantas/prevenção & controle , Raízes de Plantas/crescimento & desenvolvimento , Bacillus subtilis/classificação , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/isolamento & purificação , Camellia/metabolismo , Camellia/microbiologia , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Controle Biológico de Vetores , Desenvolvimento Vegetal , Doenças das Plantas/microbiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia
12.
Microbiol Res ; 236: 126467, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32248049

RESUMO

Strains of Xylella fastidiosa subsp. pauca characterized by a specific genotype, the so called sequence type "ST53", have been associated with a severe disease named Olive Quick Decline Syndrome (OQDS). Despite the relevant research efforts devoted to control the disease caused by X. fastidiosa, so far there are no therapeutic means able to cure the infected host plants. As such, the aim of this study was the identification of antagonistic bacteria potentially deployable as bio-control agents against X. fastidiosa. To this end, two approaches were used, i.e. the evaluation of the antagonistic activity of: i) endophytic bacteria isolated from olive trees located in an infected area but showing mild or no symptoms, and ii) Bacillus strains, as they are already known as bio-control agents. Characterization of endophytic bacterial isolates revealed that the majority belonged to different species of the genera Sphingomonas, Methylobacterium, Micrococcus and Curtobacterium. However, when they were tested in vitro against X. fastidiosa ST53 none of them showed antagonistic activity. On the contrary, when strains belonging to different species of the genus Bacillus were included in these tests, remarkable antagonistic activities were recorded. Some B. velezensis strains also produced culture filtrates with inhibitory activity against X. fastidiosa ST53. Taking also into account that two of these B. velezensis strains (namely strains D747 and QST713) are already registered and commercially available as bio-control agents, our results pave the way for further studies aimed at the development of a sustainable bio-control strategy of the OQDS.


Assuntos
Antibiose , Bacillus , Endófitos/isolamento & purificação , Olea/microbiologia , Xylella , Bacillus/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Agentes de Controle Biológico/farmacologia , DNA Bacteriano/genética , Endófitos/genética , Endófitos/metabolismo , Patologia Molecular , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , Xylella/patogenicidade
13.
Int J Syst Evol Microbiol ; 70(5): 3162-3166, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32250241

RESUMO

An endophytic member of the genus Trichoderma was isolated from the root of a healthy 3-year-old Panax notoginseng in Yunnan province, PR China. The results of phylogenetic analyses based on a combined of ITS, tef1 and rpb2 indicated that this isolate was distinct from other species of the genus Trichoderma and closely related to Trichoderma songyi. It can be distinguished from T. songyi by its slower growth rates on PDA and colony morphology. The novel isolate formed conidia in thick white pustules scattered mostly at the margin. Its conidiophores tended to be regularly verticillium-like, little branched, sometimes substituted by phialides singly or in whorls. Conidia are smooth, mostly broadly subglobose to ellipsoidal. In combination with the genotypic and phenotypic characteristics, all data demonstrated that the fungus studied represented a unique and distinguishable novel species of the genus Trichoderma, for which the name Trichoderma panacis sp. nov. is proposed.


Assuntos
Panax notoginseng/microbiologia , Filogenia , Trichoderma/classificação , China , DNA Fúngico/genética , Endófitos/classificação , Endófitos/isolamento & purificação , Técnicas de Tipagem Micológica , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Fúngicos/crescimento & desenvolvimento , Trichoderma/isolamento & purificação
14.
Arch Microbiol ; 202(6): 1563-1569, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32172289

RESUMO

Cellulosimicrobium sp. JZ28, a root endophytic bacterium from the desert plant Panicum turgidum, was previously identified as a plant growth-promoting bacterium. The genome of JZ28 consists of a 4378,193 bp circular chromosome and contains 3930 CDSs with an average GC content of 74.5%. Whole-genome sequencing analysis revealed that JZ28 was closely related to C. aquatile 3 bp. The genome harbors genes responsible for protection against oxidative, osmotic and salinity stresses, such as the production of osmoprotectants. It also contains genes with a role in the production of volatiles, such as hydrogen sulfide, which promote biotic and abiotic stress tolerance in plants. The presence of three copies of chitinase genes indicates a possible role of JZ28 as biocontrol agent against fungal pathogens, while a number of genes for the degradation of plant biopolymers indicates potential application in industrial processes. Genome sequencing and mining of culture-dependent collections of bacterial endophytes from desert plants provide new opportunities for biotechnological applications.


Assuntos
Actinobacteria , Endófitos/isolamento & purificação , Panicum/microbiologia , Desenvolvimento Vegetal/fisiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Genoma Bacteriano/genética , Plantas/microbiologia , Estresse Fisiológico
15.
PLoS One ; 15(3): e0229589, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155163

RESUMO

Securinega suffruticosa (Pall.) Rehd is an excellent natural secondary shrub in the Shell Islands of Yellow River Delta. The roots of S. suffruticosa have high medicinal value and are used to treat diseases, such as neurasthenia and infant malnutrition. Any organism that is isolated from this species is of immense interest due to its potential novel bioactive compounds. In this research, the distribution and diversity of culturable endophytic fungi in S. suffruticosa were studied, and the endophytic fungi with antimicrobial activity were screened. A total of 420 endophytic fungi isolates were obtained from the S. suffruticosa grown in Shell Islands, from which 20 genera and 35 species were identified through morphological and internal transcribed spacer (ITS) sequence analyses. Chaetomium, Fusarium, Cladosporium, and Ceratobasidium were the dominant genera. The high species richness S (42), Margalef index D' (5.6289), Shannon-Wiener index H' (3.1000), Simpson diversity index Ds (0.9459), PIE index (0.8670), and evenness Pielou index J (0.8719) and a low dominant index λ (0.0541) indicated the high diversity of endophytic fungi in S. suffruticosa, the various species of endophytic fungi with obvious tissue specificity. The inhibition percentages of the 12 species of such endophytic fungi against Colletotrichum siamense were 3.6%-26.3%. C. globosum, Fusarium sp.3, and C. ramotenellum had a high antibacterial activity against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were between 0.5 mg/mL and 2 mg/mL. Alkaloid content detection indicated that endophytic fungi had a high alkaloid content, whereas the alkaloid contents of C. globosum and Fusarium sp.3 reached 0.231% and 0.170%, respectively. Members belonging to the endophytic fungal community in the S. suffruticosa of Shell Islands that may be used as antagonists and antibacterial agents for future biotechnology applications were identified for the first time.


Assuntos
Endófitos/genética , Endófitos/fisiologia , Fungos/genética , Fungos/fisiologia , Plantas Medicinais/microbiologia , Securinega/microbiologia , Alcaloides/análise , Anti-Infecciosos/análise , Biodiversidade , China , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Endófitos/isolamento & purificação , Fungos/classificação , Testes de Sensibilidade Microbiana , Filogenia , Rios
16.
Arch Microbiol ; 202(6): 1571-1579, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32166358

RESUMO

Enterobacter cloacae is normally considered to be an opportunistic human pathogen. Here, we report on the whole-genome sequence of an endophytic E. cloacae, strain "Ghats1", isolated from leaves of the medicinal plant Coscinium fenestratum Gaertn. Functional analysis of the Ghats1 genome revealed an enrichment for genes involved in the uptake and exchange of nutrients, for chemotaxis and for plant colonization. Unexpectedly though, there were no ORFs belonging to the "virulence factors and antibiotic resistance". Moreover, the presence of hydrolytic enzymes and motility functions reveals the characteristics of an endophyte lifestyle of a bacterium that can colonize and adapt to plant environment. These results provide a better understanding of an endophytic lifestyle through plant-microbe interaction, which can be further exploited as a biocontrol agent.


Assuntos
Endófitos/isolamento & purificação , Enterobacter cloacae/genética , Genoma Bacteriano/genética , Menispermaceae/microbiologia , Aclimatação , Endófitos/genética , Enterobacter cloacae/classificação , Enterobacter cloacae/isolamento & purificação , Genômica , Humanos , Estilo de Vida , Plantas/microbiologia , Sequenciamento Completo do Genoma/métodos
17.
Microbiol Res ; 236: 126451, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146294

RESUMO

Burkholderia species have different lifestyles establishing mutualist or pathogenic associations with plants and animals. Changes in the ecological behavior of these bacteria may depend on genetic variations in response to niche adaptation. Here, we studied 15 Burkholderia strains isolated from different environments with respect to genetic and phenotypic traits. By Multilocus Sequence Analysis (MLSA) these isolates fell into 6 distinct groups. MLSA clusters did not correlate with strain antibiotic sensitivity, but with the bacterial ability to produce antimicrobial compounds and control orchid necrosis. Further, the B. seminalis strain TC3.4.2R3, a mutualistic bacterium, was inoculated into orchid plants and the interaction with the host was evaluated by analyzing the plant response and the bacterial oxidative stress response in planta. TC3.4.2R3 responded to plant colonization by increasing its own growth rate and by differential gene regulation upon oxidative stress caused by the plant, while reducing the plant's membrane lipid peroxidation. The bacterial responses to oxidative stress were recapitulated by bacterial exposure to the herbicide paraquat. We suggest that the ability of Burkholderia species to successfully establish in the rhizosphere correlates with genetic variation, whereas traits associated with antibiotic resistance are more likely to be categorized as strain specific.


Assuntos
Adaptação Biológica/genética , Infecções por Burkholderia , Burkholderia , Interações entre Hospedeiro e Microrganismos , Orchidaceae/microbiologia , Aclimatação/genética , Anti-Infecciosos/farmacologia , Agentes de Controle Biológico/farmacologia , Burkholderia/genética , Burkholderia/crescimento & desenvolvimento , Burkholderia/isolamento & purificação , Burkholderia/metabolismo , Resistência Microbiana a Medicamentos/genética , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Endófitos/metabolismo , Genes Bacterianos , Ilhas Genômicas , Genótipo , Peroxidação de Lipídeos , Tipagem de Sequências Multilocus , Orchidaceae/fisiologia , Estresse Oxidativo/genética , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , RNA Ribossômico 16S/genética , Simbiose , Transcriptoma
18.
Sci Rep ; 10(1): 3237, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32094443

RESUMO

Endophytes, both of bacterial and fungal origin, are ubiquitously present in all plants. While their origin and evolution are enigmatic, there is burgeoning literature on their role in promoting growth and stress responses in their hosts. We demonstrate that a salt-tolerant endophyte isolated from salt-adapted Pokkali rice, a Fusarium sp., colonizes the salt-sensitive rice variety IR-64, promotes its growth under salt stress and confers salinity stress tolerance to its host. Physiological parameters, such as assimilation rate and chlorophyll stability index were higher in the colonized plants. Comparative transcriptome analysis revealed 1348 up-regulated and 1078 down-regulated genes in plants colonized by the endophyte. Analysis of the regulated genes by MapMan and interaction network programs showed that they are involved in both abiotic and biotic stress tolerance, and code for proteins involved in signal perception (leucine-rich repeat proteins, receptor-like kinases) and transduction (Ca2+ and calmodulin-binding proteins), transcription factors, secondary metabolism and oxidative stress scavenging. For nine genes, the data were validated by qPCR analysis in both roots and shoots. Taken together, these results show that salt-adapted Pokkali rice varieties are powerful sources for the identification of novel endophytes, which can be used to confer salinity tolerance to agriculturally important, but salt-sensitive rice varieties.


Assuntos
Endófitos/fisiologia , Genes de Plantas , Oryza/genética , Oryza/microbiologia , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Endófitos/efeitos dos fármacos , Endófitos/isolamento & purificação , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Anotação de Sequência Molecular , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Potássio/metabolismo , Mapas de Interação de Proteínas/genética , Controle de Qualidade , Reprodutibilidade dos Testes , Salinidade , Tolerância ao Sal/efeitos dos fármacos , Sódio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Transcriptoma/genética
19.
Ecotoxicol Environ Saf ; 192: 110304, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32066006

RESUMO

The environmental release of graphene oxide (GO) will certainly induce the GO exposure to plants. To date, the influence of GO on the intracellular structures and the endophytic bacterial ecology of plants have been rarely reported. In the present study, the rice seedlings were exposed to GO (5 mg/L) under hydroponic condition for fifteen days with periodic stir. The cellular structures damage, GO deposition and oxidative stress were found in rice root after GO exposure. A Illumina analysis based on the bacterial 16 S rRNA gene showed that the richness, evenness and diversity of endophytic bacterial communities of rice root decreased due to GO exposure. The relative abundance of beneficial endophytic bacterial populations decreased after GO exposure. Out of potential phenotypes predicted by BugBase, the relative abundance of Gram negative, stress-tolerant and biofilm-forming phenotypes, presented an increase trend after GO exposure.


Assuntos
Grafite/toxicidade , Microbiota/efeitos dos fármacos , Oryza/microbiologia , Poluentes Químicos da Água/toxicidade , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Endófitos/classificação , Endófitos/efeitos dos fármacos , Endófitos/genética , Endófitos/isolamento & purificação , Grafite/metabolismo , Hidroponia , Oryza/efeitos dos fármacos , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Plântula/efeitos dos fármacos , Plântula/metabolismo , Plântula/microbiologia , Poluentes Químicos da Água/metabolismo
20.
Int J Mol Sci ; 21(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906579

RESUMO

: Dendrobium are tropical orchid plants that host diverse endophytic fungi. The role of these fungi is not currently well understood in Dendrobium plants. We morphologically and molecularly identified these fungal endophytes, and created an efficient system for evaluating the pathogenicity and symptoms of endophytic fungi on Dendrobium nobile and Dendrobium officinale though in vitro co-culturing. ReThe colony morphological traits of Dendrobium myco-endophytes (DMEs) were recorded for their identification. Molecular identification revealed the presence of Colletotrichum tropicicola, Fusarium keratoplasticum, Fusarium oxysporum, Fusarium solani, and Trichoderma longibrachiatum. The pathogenicity results revealed that T. longibrachiatum produced the least pathogenic effects against D. nobile protocorms. In seedlings, T. longibrachiatum showed the least pathogenic effects against D. officinale seedlings after seven days. C. tropicicola produced highly pathogenic effects against both Dendrobium seedlings. The results of histological examination of infected tissues revealed that F. keratoplasticum and T. longibrachiatum fulfill Koch's postulates for the existence of endophytes inside the living tissues. The DMEs are cross-transmitted inside the host plant cells, playing an important role in plant host development, resistance, and alkaloids stimulation.


Assuntos
Dendrobium/microbiologia , Endófitos/patogenicidade , Fungos/patogenicidade , Doenças das Plantas/microbiologia , Colletotrichum/genética , Colletotrichum/isolamento & purificação , Colletotrichum/patogenicidade , DNA Fúngico , Dendrobium/citologia , Endófitos/genética , Endófitos/isolamento & purificação , Fungos/citologia , Fungos/genética , Fungos/isolamento & purificação , Fusarium/genética , Fusarium/isolamento & purificação , Fusarium/patogenicidade , Filogenia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Trichoderma/genética , Trichoderma/isolamento & purificação , Trichoderma/patogenicidade
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