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1.
J Agric Food Chem ; 67(38): 10685-10693, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479251

RESUMO

Theanine is the most abundant non-protein amino acid in Camellia sinensis, but it is not known how a tea plant accumulates such high levels of theanine. The endophyte isolated from in vitro grown plantlets of C. sinensis cultivars was identified as Luteibacter spp., showing strong biocatalytic activity for converting both glutamine and ethylamine to theanine. Theanine was secreted outside of the bacteria. The endophyte isolated from in vitro plantlets of Camellia oleifera cultivar was identified as Bacillus safensis and did not convert glutamine and ethylamine to theanine. Enzymatic assays in vitro indicated that γ-glutamyltranspeptidases rCsEGGTs from the endophyte Luteibacter strains converted glutamine and ethylamine to theanine at higher rates than rCsGGTs from C. sinensis. This is the first report on theanine biosynthesis by an endophyte from C. sinensis, which provides a new pathway to explore the mechanism of theanine biosynthesis in C. sinensis and the interactions between an endophyte and tea plants.


Assuntos
Bactérias/metabolismo , Camellia sinensis/microbiologia , Endófitos/metabolismo , Glutamatos/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Camellia sinensis/química , Camellia sinensis/classificação , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Etilaminas/metabolismo , Glutamina/metabolismo , Folhas de Planta/química , Folhas de Planta/microbiologia
2.
J Agric Food Chem ; 67(38): 10646-10652, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479255

RESUMO

A new monosesquiterpene diacetylgliocladic acid (1), a new dimeric sesquiterpene divirensol H (9), and two exceptionally novel trimeric sesquiterpene trivirensols A and B (11 and 12), together with another eight known congeners, were purified from an endophytic fungus Trichoderma virens FY06, derived from Litchi chinensis Sonn. whose fruit is a delicious and popular food. All of them were identified by comprehensive spectroscopic analysis, combined with biosynthetic considerations. Trivirensols A and B are unprecedented trimers of which three subunits are connected by two ester bonds of the sesquiterpene class. Relative to the positive control triadimefon, all the tested metabolites showed strong inhibitory activities against at least one phytopathogenic fungus among Penicillium italicum, Fusarium oxysporum, Fusarium graminearum, Colletotrichum musae, and Colletotrictum gloeosporioides. Notably, as metabolites of the endophytic fungus from L. chinensis, they all presented strong antifungal activities against C. gloeosporioides which causes anthracnose in L. chinensis.


Assuntos
Fungicidas Industriais/farmacologia , Litchi/microbiologia , Sesquiterpenos/farmacologia , Trichoderma/química , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Endófitos/química , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Frutas/microbiologia , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Trichoderma/genética , Trichoderma/isolamento & purificação
3.
J Agric Food Chem ; 67(38): 10660-10666, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479263

RESUMO

Two new indolyl diketopiperazines, gartryprostatins A and B (1 and 2), with an unusual 2,3-furan-fused pyrano[2,3-g]pyrrolo[1″,2″:4',5']pyrazino[1',2':1,5]pyrrolo[2,3-b]indole nucleus, along with a new naturally occurring compound (gartryprostatin C, 3) were isolated from the solid culture of Aspergillus sp. GZWMJZ-258, an endophyte from Garcinia multiflora (Guttiferae). The structures of compounds 1-3 were determined by nuclear magnetic resonance, mass spectrometry, Marfey's analysis of amino acids, and chemical calculation. Compounds 1-3 displayed selective inhibition on human FLT3-ITD mutant AML cell line, MV4-11, with IC50 values of 7.2, 10.0, and 0.22 µM, respectively.


Assuntos
Aspergillus/química , Dicetopiperazinas/farmacologia , Endófitos/química , Garcinia/microbiologia , Plantas Medicinais/microbiologia , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dicetopiperazinas/química , Dicetopiperazinas/metabolismo , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular
4.
Microbiol Res ; 228: 126302, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31442862

RESUMO

Endophytic bacteria isolated from cactus were characterized and assessed for their capability to induce drought tolerance and growth promotion in tomato. A total of 191-bacteria representing 13-genera and 18-species were isolated from wild cactus, Euphorbia trigonas. Bacillus (58), Lysinibacillus (36), Enterobacter (29), Stenotrophomonas (18), Lelliottia (12) and Pseudomonas (12) were the most represented genera. 16S rDNA sequence (>1400-bp) comparison placed the bacterial isolates with Bacillus xiamenensis; Bacillus megaterium; Bacillus cereus; Bacillus amyloliquefaciens; Bacillus velezensis; Brevibacillus brevis; Lysinibacillus fusiformis; Enterobacter cloacae; Lelliottia nimipressuralis; Proteus penneri; Sphingobacterium multivorum; Klebsiella pneumoniae; Pseudomonas putida; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Citrobacter freundii; Chryseobacterium indologenes and Paracoccus sp. Bacillus xiamenensis was identified for the first time as plant endophyte. Upon bacterization, the endophytes triggered germination and growth promotion in tomato as indicated by 118 % and 52 % more root-biomass under drought-free and drought-induced conditions, respectively. Bacillus amyloliquefaciens CBa_RA37 and B. megaterium RR10 displayed broad spectrum endophytism in tomato. Bacterization of tomato with cactus endophyte showed altered oxidative status, stomatal and photosystem II functioning, internal leaf temperature and relative water content suggestive of physiological de-stressing from moisture stress. Activity of oxidative stress enzymes such as guaiacol peroxidase and catalase was also indicative of endophyte assisted de-stressing of tomato. Re-irrigation on 20-days of drought infliction showed 86.9% recovery of B. amyloliquefaciens CBa_RA37 primed tomato when non-primed plantlets succumbed. The cactus endophytic bacterial strain B. amyloliquefaciens CBa_RA37 showed promise for low-cost, efficient and environmentally friendly bio-inoculant technology to mitigate drought in arid zones of Asian and African continents.


Assuntos
Cactaceae/microbiologia , Secas , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/fisiologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Desenvolvimento Vegetal , Aclimatação , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/fisiologia , Biomassa , Camarões , DNA Ribossômico/genética , Clima Desértico , Endófitos/genética , Filogenia , Folhas de Planta , Raízes de Plantas , RNA Ribossômico 16S/genética , Rifamicinas/farmacologia , Análise de Sequência , Microbiologia do Solo , Estresse Fisiológico
5.
J Agric Food Chem ; 67(31): 8493-8499, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31310523

RESUMO

The ginsenosides Rh2 and Rg3 induce tumor cell apoptosis, inhibit tumor cell proliferation, and restrain tumor invasion and metastasis. Despite Rh2 and Rg3 having versatile pharmacological activities, contents of them in natural ginseng are extremely low. To produce ginsenosides Rh2 and Rg3, the saponin-producing capacity of endophytic bacteria isolated from Panax ginseng was investigated. In this work, 81 endophytic bacteria isolates were taken from ginseng roots by tissue separation methods. Among them, strain PDA-2 showed the highest capacity to produce the rare ginsenosides; the concentrations of rare ginsenosides Rg3 and Rh2 reached 62.20 and 18.60 mg/L, respectively. On the basis of phylogenetic analysis, it was found that strain PDA-2 belongs to the genus Agrobacterium and was very close to Agrobacterium rhizogenes.


Assuntos
Bactérias/metabolismo , Endófitos/metabolismo , Ginsenosídeos/biossíntese , Panax/microbiologia , Agrobacterium/classificação , Agrobacterium/genética , Agrobacterium/isolamento & purificação , Agrobacterium/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Filogenia , Raízes de Plantas/microbiologia
6.
World J Microbiol Biotechnol ; 35(7): 113, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289918

RESUMO

Camellia taliensis (W. W. Smith) Melchior is a wild tea plant endemic from the west and southwest of Yunnan province of China to the north of Myanmar and is used commonly to produce tea by the local people of its growing areas. Its chemical constituents are closely related to those of C. sinensis var. assamica, a widely cultivated tea plant. In this study, the α diversity and phylogeny of endophytic fungi in the branches of C. taliensis were explored for the first time. A total of 160 fungal strains were obtained and grouped into 42 species from 29 genera, which were identified based on rDNA internal transcribed spacer sequence analysis. Diversity analysis showed that the endophytic fungal community of the branches of C. taliensis had high species richness S (42), Margalef index D' (8.0785), Shannon-Wiener index H' (2.8494), Simpson diversity index DS (0.8891), PIE index (0.8947) and evenness Pielou index J (0.7623) but a low dominant index λ (0.1109). By contrast, that in the branches of C. taliensis had abundant species and high species evenness. Diaporthe tectonigena, Acrocalymma sp. and Colletotrichum magnisporum were the dominant endophytic fungi. The phylogenetic tree was established by maximum parsimony analysis, and the 11 orders observed for endophytic fungi belonging to Ascomycota and Basidiomycota were grouped into 4 classes.


Assuntos
Camellia/microbiologia , Endófitos/classificação , Endófitos/isolamento & purificação , Fungos/classificação , Fungos/isolamento & purificação , Filogenia , Chá , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/isolamento & purificação , Biodiversidade , China , Análise por Conglomerados , DNA Ribossômico/genética , Endófitos/genética , Fungos/genética , Mianmar , Análise de Sequência
7.
Bioengineered ; 10(1): 316-334, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31347943

RESUMO

In the development of medicinally important Orchidaceae, the extent of fungal endophytes specificity is not presently very clear. Limited study has been available on natural products formed and its role on plant growth, defence mechanism by endophytes, and to characterize the chief treasure of bioactive molecules. Therefore, this review article presents an evaluation of the endophytes associated with Orchidaceae for physiology, metabolism, and genomics which have prominently contributed to the resurgence of novel metabolite research increasing our considerate of multifaceted mechanisms regulatory appearance of biosynthetic gene groups encoding diverse metabolites. Additionally, we presented the comprehensive recent development of bio-strategies for the cultivation of endophytes from Orchidaceae and integration of bioengineered 'Genomics with metabolism' approaches with emphases collective omics as powerful approach to discover novel metabolite compounds. The Orchidaceae-fungal endophytes' biodynamics for sustainable development of bioproducts and its applications are supported in large-scale biosynthesis of industrially and pharmaceutical important biomolecules.


Assuntos
Produtos Biológicos/química , Endófitos/metabolismo , Fungos/metabolismo , Orchidaceae/microbiologia , Simbiose/fisiologia , Produtos Biológicos/isolamento & purificação , Endófitos/classificação , Endófitos/genética , Fungos/classificação , Fungos/genética , Redes e Vias Metabólicas/fisiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , Metabolismo Secundário/fisiologia
8.
Sci Total Environ ; 686: 107-117, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31176810

RESUMO

Soil salinity is one of the serious environmental issues worldwide. In the present study, we made an attempt to isolate endophytic actinobacteria from halophyte and evaluate their growth promoting ability in Arabidopsis thaliana under salt stress through transcriptomic analysis. Two endophytic strains SYSU 333322 and SYSU 333140 were isolated and 16S rRNA gene sequence analysis suggests that these strains belong to Arthrobacter endophyticus and Nocardiopsis alba, respectively. To evaluate the growth promoting ability of two strains in Arabidopsis thaliana four experimental set up were designed. Set up designated s322 and s140 includes strains SYSU 333322 and SYSU 333140, respectively inoculated with A. thaliana under salt stress; set up designated MS322 and MS140 includes strains SYSU 333322 and SYSU 333140, respectively inoculated with A. thaliana without salt stress; MS includes seedlings without bacterial strains and salt stress; C150 includes seedlings grown in 150 mmol L-1NaCl. A. endophyticus strain SYSU 333322 and N. alba strain SYSU 333140 were efficient to promote A. thaliana growth under salt stress A. endophyticus strain SYSU 333322 was more efficient than N. alba strain SYSU 333140 for growth promotion. Although A. endophyticus strain SYSU 333322 and N. alba strain SYSU 333140 were isolated from the same host, their mechanism of growth promotion in A. thaliana under salt stress was different. Gene encoding for chlorophyll a reductase, peptide-methionine (R)-S-oxide reductase, and potassium ion uptake were up-regulated when A. thaliana inoculated with strain SYSU 333322 and SYSU 333140 under salt stress. Pathways such as carotenoid biosynthesis, phenylalanine metabolism, phenylpropanoid biosynthesis, glycerolipid metabolism, and nitrogen metabolism played a crucial role in enhancing the salt stress tolerance of A. thaliana. Our results suggest that different bacteria have a different mechanism to promote plant growth under salt stress and hence it is necessary to understand the mechanism to overcome soil salinity problem.


Assuntos
Arabidopsis/fisiologia , Endófitos/genética , Arabidopsis/microbiologia , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , Rizosfera , Estresse Salino/fisiologia , Plantas Tolerantes a Sal/microbiologia , Microbiologia do Solo , Transcriptoma
9.
J Microbiol ; 57(8): 655-660, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187415

RESUMO

A Gram-negative, aerobic, short-rod-shaped, motile (with a terminal flagellum), non-spore-forming bacterium, designated strain 85T, was isolated from a surface-sterilized bark of Sonneratia caseolaris collected from Qinzhou in Guangxi, China and was analyzed using a polyphasic approach to determine its taxonomic position. Strain 85T grew optimally in the presence of 1-2% (w/v) NaCl at 30°C and pH 6.0-7.0. Phylogenetic analysis based on 16S rRNA gene sequence suggested that strain 85T belonged to the genus Fulvimarina and shared the highest 16S rRNA gene sequence similarity with Fulvimarina pelagi HTCC2506T (96.16%). The cell-wall peptidoglycan contained meso-diaminopimelic acid and ubiquinone Q-10 was the predominant respiratory lipoquinone. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified amino lipid, three unidentified phospholipids and six unidentified lipids. The major fatty acid was C18:1ω7c. The DNA G+C content of strain 85T was 65.4 mol%, and the average nucleotide identity and estimated DDH values between strain 85T and the type strain of Fulvimarina pelagi HTCC2506T were 77.3% and 21.7%, respectively. Based on the phylogenetic, phenotypic, and chemotaxonomic analyses, strain 85T should be considered as a novel species of the genus Fulvimarina with the proposed name Fulvimarina endophytica sp. nov., and its type strain is 85T (= KCTC 62717T = CGMCC 1.13665T).


Assuntos
Alphaproteobacteria/classificação , Endófitos/classificação , Lythraceae/microbiologia , Casca de Planta/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/crescimento & desenvolvimento , Alphaproteobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Composição de Bases , China , DNA Bacteriano/genética , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , RNA Ribossômico 16S/genética , Sequenciamento Completo do Genoma/métodos
10.
Microbiol Res ; 223-225: 58-62, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31178052

RESUMO

Climate change is predicted to have adverse impacts on terrestrial ecosystems and uncertainties exist on how these systems will respond. Terrestrial plant ecosystems can be divided by how they fix atmospheric carbon- C3, C4 and CAM photosynthesis pathways. However, as for now, no clear answers could be given regarding the future global repartition of the C3, C4 and CAM plants. As seeds are the reproductive and dispersal unit of the plants and endophytes play a central role in their preservation; here it is suggested that a better knowledge regarding the seeds endophytic community is needed when studying the future repartition of C3, C4 and CAM plant seeds. Bacterial endophyte communities inhabiting seeds belonging to C3, C4 and CAM annual plants were analysed by culture-dependent methods and 16S rRNA gene sequencing. Results indicated there were differences in the relative abundance of bacterial phyla within and across all photosynthetic pathways. Indicating some level of niche partitioning, and each of the three photosynthetic pathways could be characterized by a specific endophytic composition of Firmicutes, corresponding to the adaptation capacity of each group. We successfully identified resistant species of endophytes in the Firmicutes phylum of C4 and CAM plant seeds. Those bacteria are known for being involved in thermal regulation and plant protection through enzymes and antibiotic synthesis and match the strong adaptation capacity of C4 and CAM plants. Overall, this study suggests that there is a plant-mediated selection of the seed microbiome and these symbionts could potentially confer additional benefits to the seed.


Assuntos
Endófitos/fisiologia , Fotossíntese , Sementes/metabolismo , Sementes/microbiologia , Aclimatação , Bactérias/classificação , Bactérias/genética , Contagem de Colônia Microbiana , Endófitos/classificação , Endófitos/genética , Firmicutes , Israel , Microbiota , RNA Ribossômico 16S/genética
11.
World J Microbiol Biotechnol ; 35(7): 104, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31236765

RESUMO

Endophytic bacterial diversity in plants presents the level of interaction between culturable and non-culturable endophytic bacteria, thereby providing an appropriate insight into the endophytic environment. This study was conducted to determine the trend of culturable and non-culturable endophytic bacteria at two different sites encompassing four consecutive growth stages. For culturable endophytic bacteria, isolation was carried out using the dilution plate technique, and the obtained colonies were compared using PCR-restriction fragment length polymorphism (RFLP). Different RFLP-types were identified to their nearest neighbour using 16S rRNA sequencing. The non-culturable endophytic bacterial diversity was obtained by next generation sequencing. Results suggested a similar trend among the culturable and non-culturable bacteria for observed operational taxonomic units and diversity indices. It is noticeable that the endophytic bacteria inhabiting in stage 1 disappeared, and instead, different endophytic bacteria appeared. Moreover, the temporal persistence of certain culturable and non-culturable bacteria was also observed. In conclusion, the endophytic bacterial diversity in cucumber initially increased with the plant growth and then decreased at a later stage. Furthermore, it was suggested that plants regulate the number and diversity of endophytes throughout the lifecycle of plants.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Biodiversidade , Cucumis sativus/microbiologia , Endófitos/classificação , Endófitos/isolamento & purificação , Microbiota , Bactérias/genética , Cucumis sativus/crescimento & desenvolvimento , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Endófitos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota/genética , Filogenia , Raízes de Plantas/microbiologia , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética
12.
Mycorrhiza ; 29(4): 313-324, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129728

RESUMO

Restoration of the American chestnut (Castanea dentata) is underway using backcross breeding that confers chestnut blight disease resistance from Asian chestnuts (most often Castanea mollissima) to the susceptible host. Successful restoration will depend on blight resistance and performance of hybrid seedlings, which can be impacted by below-ground fungal communities. We compared fungal communities in roots and rhizospheres (rhizobiomes) of nursery-grown, 1-year-old chestnut seedlings from different genetic families of American chestnut, Chinese chestnut, and hybrids from backcross breeding generations as well as those present in the nursery soil. We specifically focused on the ectomycorrhizal (EcM) fungi that may facilitate host performance in the nursery and aid in seedling establishment after outplanting. Seedling rhizobiomes and nursery soil communities were distinct and seedlings recruited heterogeneous communities from shared nursery soil. The rhizobiomes included EcM fungi as well as endophytes, putative pathogens, and likely saprobes, but their relative proportions varied widely within and among the chestnut families. Notably, hybrid seedlings that hosted few EcM fungi hosted a large proportion of potential pathogens and endophytes, with possible consequences in outplanting success. Our data show that chestnut seedlings recruit divergent rhizobiomes and depart nurseries with communities that may facilitate or compromise the seedling performance in the field.


Assuntos
Fagaceae/microbiologia , Fungos/isolamento & purificação , Microbiota , Micorrizas/isolamento & purificação , Doenças das Plantas/imunologia , Biodiversidade , Resistência à Doença , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Fagaceae/genética , Fagaceae/imunologia , Fungos/classificação , Fungos/genética , Hibridização Genética , Micorrizas/classificação , Micorrizas/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Microbiologia do Solo
13.
Fungal Biol ; 123(5): 373-383, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31053326

RESUMO

A total of 266 endophytic fungal isolates were recovered from 1019 tissue segments of Glycyrrhiza glabra collected from four different locations in the North-Western Himalayas. The endophytes grouped into 21 genera and 38 different taxa. The host had strong affinity for the genus Phoma, followed by Fusarium. The species richness was highest at the sub-tropical location, followed by the sub-temperate location and the temperate locations, respectively. The tissue specificity of endophytes was also evident. Some endophytes showed potential antimicrobial activity against phyto-pathogens indicating that they may be helpful to the host in evading pathogens. All the endophytic taxa produced the plant growth promoting hormone, indole acetic acid (IAA), though in varying concentrations. None of these endophytes caused any symptoms of disease in co-cultivation with the tissue cultured plants. Further, all the endophytes had a positive influence on the phenolic and flavonoid content of the host. Three endophytes, Stagonosporopsis cucurbitacearum, Bionectria sp. and Aspergillus terreus also increased the host root (rhizome) and shoot growth visibly. Such endophytes are potential candidates for developing endophyte-based technologies for sustainable cultivation and enhanced productivity of G. glabra. This is the first report of community structure and biological properties of fungal endophytes associated with G. glabra.


Assuntos
Endófitos/classificação , Endófitos/isolamento & purificação , Fungos/classificação , Fungos/isolamento & purificação , Glycyrrhiza/microbiologia , Simbiose , Anti-Infecciosos/metabolismo , Endófitos/genética , Endófitos/fisiologia , Fungos/genética , Fungos/fisiologia , Índia , Desenvolvimento Vegetal
14.
J Microbiol ; 57(9): 725-731, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31124044

RESUMO

A Gram-staining-positive, motile and short-rod-shaped actinobacterium designated 9W16Y-2T was isolated from surface-sterilized leaves of reed (Phragmites australis) collected from Taklamakan Desert in Xinjiang Uygur Autonomous Region, China. Colonies were pale greenish yellow, circular, smooth, and convex. The 16S rRNA gene sequence of strain 9W16Y-2T exhibited highest sequence similarities with Aeromicrobium camelliae CGMCC 1.12942T (99.0%) and Aeromicrobium erythreum NRRL B-3381T (97.2%). Phylogenetic analyses based on 16S rRNA gene sequences and single-copy phylogenetic marker genes (pMGs) showed that strain 9W16Y-2T belonged to the genus Aeromicrobium and formed a monophyletic clade with Aeromicrobium camelliae CGMCC 1.12942T. Furthermore, average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) clearly separated strain 9W16Y-2T from the other species of the genus Aeromicrobium with values below the thresholds for species delineation. The G+C content of the genomic DNA is 68.9 mol%. The diagnostic diamino acid of the cell-wall peptidoglycan was LL-diaminopimelic acid. The predominant menaquinone was MK-9(H4). The major fatty acids (> 10% of the total fatty acids) were C18:0 10-methyl (TBSA) (28.2%), C16:0 (21.0%), C16:0 2-OH (20.8%) and C18:1ω9c (12.8%). The polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, an unidentified aminophospholipid and an unidentified lipid. Based on the phylogenic, phenotypic and chemotaxonomic features, strain 9W16Y-2T represents a novel species of the genus Aeromicrobium, for which the name Aeromicrobium endophyticum sp. nov. is proposed. The type strain is 9W16Y-2T (= CGMCC 1.13876T = JCM 33141T).


Assuntos
Actinobacteria/isolamento & purificação , Endófitos/isolamento & purificação , Poaceae/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/metabolismo , Técnicas de Tipagem Bacteriana , Parede Celular/química , Parede Celular/metabolismo , China , DNA Bacteriano/genética , Endófitos/classificação , Endófitos/genética , Endófitos/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Peptidoglicano/química , Peptidoglicano/metabolismo , Filogenia , RNA Ribossômico 16S/genética
15.
J Agric Food Chem ; 67(24): 6828-6836, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31136163

RESUMO

Verticillium wilt, caused by Verticillium dahliae, results in a dramatic loss of cotton yields in China. There is great potential for biocontrol to manage this destructive crop disease. In this study, we obtained the endophytic bacterium Bacillus halotolerans Y6 from Verticillium wilt-resistant cotton Gossypium barbadense Xinhai15; this bacterium possesses strong antagonistic abilities that inhibit V. dahliae spore germination and mycelial growth. The results of the enzyme activity assay, heterologous expression, and gene knockdown showed that the key virulence factor of Y6 for antagonizing V. dahliae was ß -glucanase Bgy6. To facilitate field tests of biological control, we constructed the homologous Bgy6-overexpression strain OY6. Compared with the wild-type Y6 strain, the ß-glucanase activity of OY6 was increased by 91.79%, and the inhibition rate of OY6 against V. dahliae V991 exceeded 96.7%. Moreover, the spores of V. dahliae V991 treated with OY6 showed more mucus and larger holes on the surface, as observed by scanning electron microscopy. Potting test results illustrated that both OY6 and Y6 could improve the resistance of upland cotton to Verticillium wilt. With the inoculation of V. dahliae V991 for 45 days, the disease index of G. hirsutum TM-1 treated with OY6 was only 8.33, which was significantly lower than that in plants treated with the wild-type strain Y6 (17.86) or the controls without bacteria (35.94). Our research provides a new idea for the control of Verticillium wilt in upland cotton via transforming endophytic bacteria of Verticillium wilt-resistant cotton and proposes a new solution to prevent and control Verticillium wilt.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/genética , Endo-1,3(4)-beta-Glucanase/genética , Endófitos/enzimologia , Gossypium/microbiologia , Doenças das Plantas/imunologia , Verticillium/fisiologia , Fatores de Virulência/genética , Antibiose , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/fisiologia , Proteínas de Bactérias/metabolismo , Resistência à Doença , Endo-1,3(4)-beta-Glucanase/metabolismo , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/fisiologia , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Gossypium/imunologia , Doenças das Plantas/microbiologia , Fatores de Virulência/imunologia
16.
Microbiome ; 7(1): 57, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967154

RESUMO

BACKGROUND: Revealing the relationship between plants and fungi is very important in understanding biodiversity maintenance, community stability, and ecosystem functioning. However, differences in the community and network structures of phyllosphere epiphytic and endophytic fungi are currently poorly documented. In this study, we examined epiphytic and endophytic fungal communities associated with the leaves of six mangrove species using Illumina MiSeq sequencing of internal transcribed spacer 2 (ITS2) sequences. RESULTS: A total of 635 operational taxonomic units (OTUs) of endophytic and epiphytic fungi were obtained at a 97% sequence similarity level; they were dominated by Dothideomycetes and Tremellomycetes. Plant identity had a significant effect on the OTU richness of endophytic fungi, but not on epiphytic fungi. The community composition of epiphytic and endophytic fungi was significantly different, and plant identity had a greater effect on endophytic fungi than on epiphytic fungi. Network analysis showed that both epiphytic and endophytic network structures were characterized by significantly highly specialized and modular but lowly connected and anti-nested properties. Furthermore, the endophytic network had higher levels of specialization and modularity but lower connectance and stronger anti-nestedness than the epiphytic network. CONCLUSIONS: This study reveals that the phyllosphere epiphytic and endophytic fungal communities differ, and plant identity has a greater effect on the endophytic fungi than on epiphytic fungi. These findings demonstrate the role of host plant identity in driving phyllosphere epiphytic and endophytic community structure.


Assuntos
Fungos/classificação , Plantas/microbiologia , Análise de Sequência de DNA/métodos , Biodiversidade , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Fungos/genética , Fungos/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Filogenia , Áreas Alagadas
17.
J Basic Microbiol ; 59(7): 713-722, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30994190

RESUMO

Plant endophytes are rich in secondary metabolites and are widely used in medicine, chemical, food, agriculture, and other fields. Here, an endophytic fungus is isolated from Ginkgo biloba L. leaves and identified as Alternaria brassicae GL07 through genotypic characterizations. It can produce fruity scented volatiles. The analysis of volatile organic compounds (VOCs) was done by gas chromatography-mass spectrometry. A total of 32 components were identified; and at different culture times, the composition of VOCs was different. It had more components in the first two weeks, but a fewer components on the 21st day. More olefins, ketone, aldehyde, and alcohol were found in the growth period and more amines and esters were found in the decline period. Also, 2,5-dihydroxyacetophenone, ß-ionone, and nonanal were found. They were the same ingredients in Ginkgo essential oils and some of them were isolated for the first time in the volatile constituents of endophytes. The antioxidant activity and whitening activities of all extracts were also evaluated. When cultured for 10 days, it had the strongest 2,2-diphenyl-2-picrylhydrazyl radical (IC50 , 0.56 g/L), hydroxyl radical scavenging ability (IC50 , 0.47 g/L), reducing ability, and tyrosinase inhibition ability (IC50 , 5.18 g/L), which may be due to a large amount of ketones and alcohols produced during the log phase. This demonstrates the potential of A. brassicae GL07 to produce bioactive compounds and to be used for perfume and cosmetic industries.


Assuntos
Alternaria/química , Alternaria/crescimento & desenvolvimento , Antioxidantes/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Alternaria/classificação , Alternaria/genética , Endófitos/química , Endófitos/classificação , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Ginkgo biloba/microbiologia , Oxirredução , Filogenia , Extratos Vegetais/química , Folhas de Planta/microbiologia , Compostos Orgânicos Voláteis/química
18.
Microbiol Res ; 221: 10-14, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30825937

RESUMO

The culturable bacteria from root nodules of Sulla coronaria growing in spontaneous conditions in Sardinia were characterized. This plant's peculiarity is to represent a legume still found in both wild and cropped statuses. We tested whether culturable bacteria would differ from those commonly isolated from its field-cropped varieties, to date exclusively represented by Rhizobium sullae. 63 isolates from 60 surface-sterilized nodules were analyzed by ARDRA and 16S rDNA sequencing. The official nitrogen-fixing symbiont Rhizobium sullae was found only in 25 nodules out of 60. The remaining nodules did not yield culturable rhizobia but a number of different endophytic genera including Pseudomonas sp. (17 nodules), Microbacterium sp. (15 nodules), Pantoea agglomerans (5 nodules). The situation appears therefore a hybrid between what is commonly observed in other Mediterranean legumes occurring only in wild status (featuring non-culturable rhizobia and arrays of culturable endophytes within nodules), as opposed to cropped legumes (endowed with fully culturable rhizobia and minimal endophytic occurrence). These findings, within a species bridging the ecology between native and cropped conditions, suggest insights on the relative importance of endophytic co-occupancy vs. true N-fixing symbiont culturability within nodules. The latter trait thus appears to accompany the domestication path of plants with a main trade-off of renouncing to interactions with a diversity of endophytic co-invaders; the relationships with those being critical in the non-cropped status. In fact, endophytes are known to promote plant growth in harsh conditions, which can be particularly stressful in the Mediterranean due to drought, highly calcareous soils, and pathogens outbreaks.


Assuntos
Endófitos/isolamento & purificação , Fabaceae/microbiologia , Rhizobium/isolamento & purificação , Nódulos Radiculares de Plantas/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Endófitos/classificação , Endófitos/genética , Microbiota , Pantoea/genética , Pantoea/isolamento & purificação , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Rhizobium/classificação , Rhizobium/genética , Análise de Sequência de DNA , Simbiose
19.
Microbiol Res ; 221: 36-49, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30825940

RESUMO

Endophytic bacteria are the plant beneficial bacteria that thrive inside plants and can improve plant growth under normal and challenging conditions. They can benefit host plants directly by improving plant nutrient uptake and by modulating growth and stress related phytohormones. Indirectly, endophytic bacteria can improve plant health by targeting pests and pathogens with antibiotics, hydrolytic enzymes, nutrient limitation, and by priming plant defenses. To confer these benefits, the bacteria have to colonize the plant endosphere after colonizing the rhizosphere. The colonization is achieved using a battery of traits involving motility, attachment, plant-polymer degradation, and evasion of plant defenses. The diversity of endophytic colonizers depends on several bacteria, plant and environment specific factors. Some endophytic bacteria can have a broad host range and can be used as bioinoculants in developing a safe and sustainable agriculture system. This review elaborates the factors affecting diversity of bacterial endophytes, their host specificity and mechanisms of plant growth promotion. The review also accentuates various methods used to study endophytic communities, wild plants as a source of novel endophytic bacteria, and innovative approaches that may improve plant-endophyte association. Moreover, bacterial genes expressed in planta and challenges to study them are also discussed.


Assuntos
Bactérias/metabolismo , Endófitos/metabolismo , Desenvolvimento Vegetal/fisiologia , Raízes de Plantas/microbiologia , Plantas/microbiologia , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Especificidade de Hospedeiro , Rizosfera , Simbiose/fisiologia
20.
J Agric Food Chem ; 67(13): 3554-3564, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30860831

RESUMO

Cynomorium songaricum Rupr. is a valuable food and medicinal plant with functions, such as an increase in sexual function, mainly attributed to its complex secondary metabolites. However, the effect of internal microbes on metabolite production in C. songaricum is still largely unclear. In this study, the relationship between endophytes and differential secondary metabolites in C. songaricum from seven major producing regions of China were explored based on established methods of metabolomics and high-throughput sequencing. The results showed that there were 13 different marker metabolites, seven shared fungal OTUs, and numerous unshared OTUs among C. songaricum distributed at different locations in China and identified significant correlations between metabolites and endophytic fungi. Our study revealed that endophytic fungi may be one possible factor that can affect the plant secondary metabolite composition.


Assuntos
Cynomorium/microbiologia , Endófitos/isolamento & purificação , Fungos/isolamento & purificação , Micobioma , Plantas Medicinais/microbiologia , China , Cynomorium/química , Cynomorium/metabolismo , Clima Desértico , Endófitos/classificação , Endófitos/genética , Fungos/classificação , Fungos/genética , Plantas Medicinais/química , Plantas Medicinais/metabolismo
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