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1.
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
2.
PLoS One ; 15(6): e0234537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574172

RESUMO

Plant-soil feedback studies attempt to understand the interplay between composition of plant and soil microbial communities. A growing body of literature suggests that plant species can coexist when they interact with a subset of the soil microbial community that impacts plant performance. Most studies focus on the microbial community in the soil rhizosphere; therefore, the degree to which the bacterial community within plant roots (root-endophytic compartment) influences plant-microbe interactions remains relatively unknown. To determine if there is an interaction between conspecific vs heterospecific soil microbes and plant performance, we sequenced root-endophytic bacterial communities of five tallgrass-prairie plant species, each reciprocally grown with soil microbes from each hosts' soil rhizosphere. We found evidence of plant-soil feedbacks for some pairs of plant hosts; however, the strength and direction of feedbacks varied substantially across plant species pairs-from positive to negative feedbacks. Additionally, each plant species harbored a unique subset of root-endophytic bacteria. Conspecifics that hosted similar bacterial communities were more similar in biomass than individuals that hosted different bacterial communities, suggesting an important functional link between root-endophytic bacterial community composition and plant fitness. Our findings suggest a connection between an understudied component of the root-endophytic microbiome and plant performance, which may have important implications in understanding plant community composition and coexistence.


Assuntos
Microbiota/genética , Desenvolvimento Vegetal/genética , Plantas/microbiologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Endófitos/classificação , Endófitos/genética , Pradaria , Filogenia , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Plantas/genética , RNA Ribossômico 16S/genética , Rizosfera
3.
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
4.
Tree Physiol ; 40(8): 1080-1094, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32333677

RESUMO

Dark septate endophytes (DSEs) are one of the most studied groups of root fungal endophytes in recent years. However, the effects of DSE on host plant are still under debate, and the molecular mechanisms are poorly understood. In this study, we identified a DSE fungus of the genus Anteaglonium, named T010, from the wild blueberry. When inoculated into Vaccinium corymbosum L. plants, T010 could enhance root growth and promote shoot branching, leading to increased plant growth. By comparative transcriptome analysis, we obtained 1948 regulated differentially expressed genes (DEGs) from the V. corymbosum plants treated by T010. Further functional enrichment analysis identified a series of DEGs enriched in transcriptional regulation, material transport, phytohormone biosynthesis and flavonoid biosynthesis. Moreover, the comparative analysis of liquid chromatography-mass spectrometry verified that T010 treatment induced the changes in the contents of various phytohormones and flavonoids. This is the first report on the isolation of DSE fungi of the genus Anteaglonium from blueberry roots. Moreover, our results suggested that T010 colonization could result in a series of changes in cell metabolism, biosynthesis and signal pathways, thereby promoting plant growth. Particularly, the changes of phytohormone and flavonoid metabolism induced by T010 colonization might contribute to the promotion of blueberry growth. Our results will provide new insights into understanding of the interaction of DSE fungi and host plants, as well as the development and utilization of DSE preparations.


Assuntos
Mirtilos Azuis (Planta) , Endófitos/genética , Flavonoides , Genes de Plantas , Reguladores de Crescimento de Planta , Raízes de Plantas/genética
5.
Arch Microbiol ; 202(7): 1717-1728, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32313992

RESUMO

Paeonia ludlowii is indigenous to Tibet and has an important ecological and economic value in China. In Tibet, P. ludlowii has been used in folk medicine with relative success. Plant microbial endophytes play an important role in plant growth, health and ecological function. The diversity of endophytic bacteria associated with P. ludlowii remains poorly understood. In this study, the structure of the endophytic bacterial communities associated with different tissues, including fruits, flowers, leaves, stems, and roots, and rhizosphere soils was analyzed with Illumina MiSeq sequencing of bacterial 16S rDNA. A total of 426,240 sequences and 4847 operational taxonomic units (OTUs) were obtained. The OTUs abundance of roots was higher than that of other tissues; however, the OTUs abundance was similar among different deep soil samples. In the plant tissues, Cyanobacteria was the most abundant bacterial phylum, followed by Proteobacteria; however, the most abundant phyla were Proteobacteria and Acidobacteria in soil samples from three different layers. In addition, the diversity and richness of the microorganisms in the soil were very similar to those in roots but higher than those in other tissues of P. ludlowii. Predictive metagenome analysis revealed that endophytic bacteria play critical functional roles in P. ludlowii. This conclusion could facilitate the study of the ecological functions of endophytic bacteria and their interactions with P. ludlowii to analyze the reasons why this important medicinal plant is becoming endangered.


Assuntos
Biodiversidade , Espécies em Perigo de Extinção , Endófitos/classificação , Endófitos/fisiologia , Paeonia/microbiologia , Rizosfera , Microbiologia do Solo , Cianobactérias/genética , Cianobactérias/isolamento & purificação , DNA Ribossômico/genética , Endófitos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Raízes de Plantas/microbiologia , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética , Tibet
6.
PLoS One ; 15(4): e0230924, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240208

RESUMO

The endophytic bacterial diversity of rose was analyzed by high-throughput sequencing of 16S rDNA and functional prediction of the bacterial community. The number of bacterial sequence reads obtained from 18 rose samples ranged from 63,951 to 114,833, and reads were allocated to 1982 OTUs based on sequences of the V3-V4 region. The highest Shannon Index was found in Luogang rose (1.93), while the lowest was found in Grasse rose (0.35). The bacterial sequence reads were grouped into three different phyla: Firmicutes, Proteobacteria, and Actinobacteria. At the genus level, Bacillus and Staphylococcus had the highest abundance across all 18 samples; Bacillus was particularly abundant in Daguo rose (99.09%), Rosa damascena (99.65%), and Fenghua rose (99.58%). Unclassified OTUs were also found in all samples. PICRUSt gene prediction revealed that each endophyte sample contained multiple KEGG functional modules related to human metabolism and health. A high abundance of functional genes were involved in (1) Amino Acid Metabolism, (2) Carbohydrate Metabolism, (3) Cellular Processes and Signaling, (4) Energy Metabolism, and (5) Membrane Transport, indicating that the endophytic community comprised a wide variety of microorganisms and genes that could be used for further studies. The rose endophytic bacterial community is rich in diversity; community composition varies among roses and contains functional information related to human health.


Assuntos
Bactérias/genética , Endófitos/genética , Rosa/microbiologia , Biodiversidade , China , Análise por Conglomerados , DNA Bacteriano/genética , DNA Ribossômico/genética , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , RNA Ribossômico 16S/genética , Rosa/genética , Análise de Sequência de DNA
7.
Planta Med ; 86(13-14): 997-1008, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32294787

RESUMO

Medicinal plants of the genus Hypericum are rich sources of bioactive naphthodianthrones, which are unique in the plant kingdom, but quite common in fungal endophytes. Cultivable endophytic fungi were isolated from 14 different Hypericum spp. originating from seeds grown under in vitro conditions and further acclimated to outdoor conditions. Among 37 fungal isolates yielded from the aerial and underground plant organs, 25 were identified at the species level by the fungal barcode marker internal transcribed spacer rDNA and protein-coding gene region of tef1α. Ten of them were isolated from Hypericum spp. for the first time. The axenic cultures of the isolated endophytes were screened for the production of extracellular enzymes, as well as bioactive naphthodianthrones and their putative precursors by Bornträger's test and HPLC-HRMS. Traces of naphthodianthrones and their intermediates, emodin, emodin anthrone, skyrin, or pseudohypericin, were detected in the fungal mycelia of Acremonium sclerotigenum and Plectosphaerella cucumerina isolated from Hypericum perforatum and Hypericum maculatum, respectively. Traces of emodin, hypericin, and pseudohypericin were released in the broth by Scedosporium apiospermum, P. cucumerina, and Fusarium oxysporum during submerged fermentation. These endophytes were isolated from several hypericin-producing Hypericum spp. Taken together, our results reveal the biosynthetic potential of cultivable endophytic fungi harbored in Hypericum plants as well as evidence of the existence of remarkable plant-endophyte relationships in selected non-native ecological niches. A possible role of the extracellular enzymes in plant secondary metabolism is discussed.


Assuntos
Hypericum , Plantas Medicinais , Endófitos/genética , Fungos/genética , Metabolismo Secundário , Sementes
8.
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
9.
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
10.
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
11.
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
12.
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
13.
Artigo em Inglês | MEDLINE | ID: mdl-31936472

RESUMO

Plant endophytes are microbial sources of bioactive secondary metabolites, which mimic the natural compounds chemistry of their respective host plants in a similar manner. This study explored the isolation and identification of fungal endophytes, and investigated the antibacterial and antimycobacterial activity of their crude extracts. Fungal endophytes were isolated from Solanum mauritianum, identified using morphological traits and internal transcribed spacer ribosomal-deoxyribonucleic acid (ITS-rDNA) sequence analysis. Eight fungal endophytes were identified as Aureobasidium pullulans, Paracamarosporium leucadendri, Cladosporium sp., Collectotrichum boninense, Fusarium sp., Hyalodendriella sp., and Talaromyces sp., while Penicillium chrysogenum was isolated from the leaves and unripe fruits. Good activity was observed for the crude extracts of Paracamarosporium leucadendri inhibiting Mycobacterium bovis, Klebsiella pneumoniae, and Pseudomonas aeruginosa at 6 µg/mL. Crude extracts of Fusarium sp., showed activity at 9 µg/mL against M. bovis, M. smegmatis and K. pneumonia. In general, the crude extracts showed great activity against Gram-negative and Gram-positive bacteria and novel results for two mycobacteria species M. bovis and M. smegmatis. The results provide evidence of diverse fungal endophytes isolated from Solanum mauritianum, and evidence that fungal endophytes are a good source of bioactive compounds with pharmaceutical potential, particularly against Mycobacterium tuberculosis.


Assuntos
Endófitos/classificação , Fungos/isolamento & purificação , Folhas de Planta/microbiologia , Solanum/microbiologia , Antibacterianos/farmacologia , Endófitos/genética , Testes de Sensibilidade Microbiana
14.
J Agric Food Chem ; 68(4): 1126-1135, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31891261

RESUMO

Phenylpropanoid (PPPN) compounds are widely used in agriculture, medical, food, and cosmetic industries because of their multiple bioactivities. Alternaria sp. MG1, an endophytic fungus isolated from grape, is a new natural source of PPPNs. However, the PPPN biosynthesis pathway in MG1 tends to be suppressed under normal growth conditions. Starvation has been reported to stimulate the PPPN pathway in plants, but this phenomenon has not been well studied in endophytic fungi. Here, metabolomics analysis was used to examine the profile of PPPN compounds, and quantitative reverse transcription-polymerase chain reaction was used to detect the expression of key genes in the PPPN biosynthesis pathway under starvation conditions. Starvation treatment significantly increased the accumulation of shikimate and PPPN compounds and upregulated the expression of key genes in their biosynthesis pathways. In addition to previously reported PPPNs, sinapate, 4-hydroxystyrene, piceatannol, and taxifolin were also detected under starvation treatment. These findings suggest that starvation treatment provides an effective way to optimize the production of PPPN compounds and may permit the investigation of compounds that are undetectable under normal conditions. Moreover, the diversity of its PPPNs makes strain MG1 a rich repository of valuable compounds and an extensive genetic resource for future studies.


Assuntos
Alternaria/metabolismo , Endófitos/metabolismo , Vitis/metabolismo , Vitis/microbiologia , Alternaria/genética , Alternaria/isolamento & purificação , Vias Biossintéticas , Ácidos Cumáricos/metabolismo , Endófitos/genética , Endófitos/isolamento & purificação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Metabolômica , Fenóis/metabolismo , Quercetina/análogos & derivados , Quercetina/biossíntese , Metabolismo Secundário , Estilbenos/metabolismo
15.
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
16.
PLoS One ; 15(1): e0227671, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31945106

RESUMO

Deciphering the various types of interactions between plants and their microbiomes is a hot topic for research in ecology as well as in plant sciences and agronomy. To analyse and compare the differences in microbial communities in different compartments of Chinese chives, high-throughput sequencing technology was employed to amplify and sequence the V5-V6 region of the 16S rDNA of microorganisms in the leaves, phylloplanes, stems, roots and rhizospheres of Chinese chives. The sequences were clustered by operational taxonomic units (OTUs), and the community composition of bacteria between the endosphere (inner tissues) and ectosphere (outer surfaces) of Chinese chives was analysed based on the OTU. Overall, the results indicated that the endophytic bacteria in Chinese chives mainly include Proteobacteria, Actinobacteria, and Actinomycetes. Alpha diversity index analysis and OTU number analysis showed that the bacterial diversity and richness of the underground plant compartments were higher than those of the above-ground parts. PCoA based on the OTU level showed that the vertical stratification structure of plants and compartments had significant effects on the bacterial community structure. The richness of endophytic bacteria also varied greatly among the different varieties of Chinese chive. A considerable number of endophytic bacteria form symbiotic and mutually beneficial relationships with host plants, which play an important role in regulating host growth, metabolism and stress resistance. Further investigations are needed to uncover the evolution of interactions between plants and endophytes.


Assuntos
Bactérias/genética , Cebolinha-Francesa/microbiologia , Microbiota/genética , Bactérias/classificação , Biodiversidade , China , Cebolinha-Francesa/anatomia & histologia , DNA Bacteriano/genética , DNA Ribossômico/genética , Endófitos/genética , Interações entre Hospedeiro e Microrganismos/genética , RNA Ribossômico 16S/genética , Simbiose/genética
17.
Arch Microbiol ; 202(1): 17-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31444513

RESUMO

The role and activity of bacterial endophytes remains largely unexplored and detail insight into Indian rice agro ecosystem is still little explored. In this study, we examined the diversity of endophytic bacteria in aerobic rice (variety ARB6) under aerobic and flooded field conditions. Based on 16S rRNA gene RFLP cloning sequencing, 900 clones with 144 representatives (72 aerobic and 72 flooded) revealed majority of clones affiliated to Gammaproteobacteria (64.58%), Betaproteobacteria (9.72%), Alphaproteobacteria (17.36), Firmicutes (6.26%) and Bacteroidetes (2.08). The study suggests that the aerobic rice variety harbours plant growth promoting (PGP) genera (viz. Pantoea, Enterobacter, Paenibacillus, etc). Investigations on aerobic rice under aerobic and flooded conditions revealed high richness and diversity of endophytic bacteria under aerobic condition inferring that the endophytic bacteria are beneficial for rice growth and productivity, and hence, would be helpful in designing better strategies for rice cultivation under drought or water scarce conditions.


Assuntos
Bactérias/genética , Biodiversidade , Endófitos/genética , Oryza/microbiologia , Aerobiose , Anaerobiose , Bactérias/classificação , Ecossistema , Endófitos/classificação , RNA Ribossômico 16S/genética , Clima Tropical
18.
Microbiol Res ; 231: 126371, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31734584

RESUMO

Eleven soil samples were collected from different plantations at the Forestry Model Base, Northeast Forestry University, China (45°43'10″N, 126°37'15″E), and 122 Trichoderma strains (T1-T122) were isolated. Nine Trichoderma species were identified based on morphological and molecular classification methods. The diversity of woody fungi was analyzed based on the type and quantity of Trichoderma spp. in the soil samples isolated from each plantation. Subdominant T. pseudoharzianum T17 (TpsT17) was screened and its biocontrol potential against Fusarium oxysporum CFCC86068 (Fox68) and growth promotion of Populus davidiana × P. alba var. pyramidalis (PdPap) seedlings were investigated. Compared with PdPap + Fox68 treatment, PdPap + TpsT17 + Fox68 treatment had an obvious antagonistic effect on Fox68 based on the status of roots and stomata of the poplar seedlings. In addition, pretreatment with TpsT17 increased catalase activity 14-fold and decreased hydrogen peroxide and malondialdehyde concentrations 2.57- and 7-fold, respectively, in the PdPap + TpsT17 + Fox68 treatment compared with the PdPap + Fox68 treatment. The transcription levels of PR1, JAZ6751, MYC2, MP, and JAR1 in PdPap + TpsT17+Fox68-treated plants were upregulated 5.75-, 5.63-, 14.88-, 8.24-, and 10.45-fold, respectively, at 3 d, while LAX2 exhibited little change in comparison with the level in PdPap + Fox-treated plants. TpsT17 was detected in the roots and stems of PdPap + TpsT17- and PdPap + TpsT17+Fox68-treated PdPap 28 d after inoculation, which demonstrated the endogenous capacity of TpsT17.


Assuntos
Endófitos/isolamento & purificação , Fusarium/crescimento & desenvolvimento , Populus , Trichoderma , Antibiose , Antifúngicos , Agentes de Controle Biológico , Catalase/metabolismo , DNA Espaçador Ribossômico , Endófitos/genética , Endófitos/metabolismo , Agricultura Florestal , Genes Fúngicos , Micoses/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Populus/enzimologia , Populus/microbiologia , Plântula/metabolismo , Microbiologia do Solo , Trichoderma/genética , Trichoderma/isolamento & purificação , Trichoderma/metabolismo
19.
Syst Appl Microbiol ; 43(1): 126025, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31704194

RESUMO

The main goal of the study was to determine the structure of endophytic bacteria inhabiting different parts (endosperm, germ, roots, coleoptiles, and leaves) of two wheat species, Triticum aestivum L. (cv. 'Hondia') and Triticum spelta L. (cv. 'Rokosz'), in order to provide new knowledge about the stability and/or changeability of the core microbiome in different plant organs. The endophytic core microbiome is associated with plants throughout their whole life cycle; however, plant organs can determine the actual endophytic community. Therefore, next generation sequencing with MiSeq Illumina technology was applied to identify the endophytic microbiome of T. aestivum and T. spelta. Bioinformatic analyses were performed with the use of the DADA2(1.8) package and R software (3.5.1). It was demonstrated that wheat, which is an important crop plant, was associated with beneficial endophytic bacteria inside the endosperms, germs, roots, leaves, and coleoptiles. Importantly, for the first time, biodiversity was recognized in the coleoptiles of the investigated wheat species. Flavobacterium, Pseudomonas and Janthinobacterium were shown to be common genera for both tested wheat cultivars. Among them, Pseudomonas was found to be the only endophytic genus accompanying both wheat species from the endosperm stage to the development of the leaf. Paenibacillus was recognized as a core genus for the 'Hondia' cv., whereas Pedobacter and Duganella constituted the core microbiome in the 'Rokosz' cv. In addition, the first insight into the unique and yet unrecognized endophytic microbiome of T. spelta is presented.


Assuntos
Microbiota , Triticum/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Microbiota/genética , Especificidade de Órgãos , Estruturas Vegetais/microbiologia , Especificidade da Espécie , Triticum/genética
20.
J Appl Microbiol ; 128(3): 747-762, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31710165

RESUMO

AIMS: Different endophytic fungi were isolated and screened for their digoxin-producing ability. Strain improvement and different culture conditions were studied for more effective production of digoxin. METHODS AND RESULTS: Among the isolated fungi, an isolate produced digoxin in a concentration of 2·07 mg l-1 . The digoxin-producing fungal isolate was identified as Epicoccum nigrum Link according to the morphological features and phylogenetic analyses. The potentiality of the fungal strain for production enhancement of digoxin was performed by gamma radiation mutagenesis. Gamma irradiation dose of 1000 Gy intensified the digoxin yield by five-fold. Using this dose, a stable mutant strain with improved digoxin productivity was isolated and the stability for digoxin production was followed up across four successive generations. In the effort to increase digoxin magnitude, selection of the proper cultivation medium, addition of some elicitors to the most proper medium and several physical fermentation conditions were tested. Fermentation process carried out in malt extract autolysate medium (pH 6·5) supplemented by methyl jasmonate and inoculated with 2 ml of 6-day-old culture and incubated at 25°C for 10 days stimulated the highest production of digoxin to attain 50·14 mg l-1 . Moreover, cytotoxicity of digoxin separated from the fungal culture was tested against five different cancer cell lines. Based on the MTT assay, digoxin inhibited the proliferation of the five different cancer cell lines and the recorded 50% inhibitory concentration ranged from 10·76 to 35·14 µg ml-1 . CONCLUSIONS: This is the first report on the production and enhancement of digoxin using fungal fermentation as a new and alternate source with high productivity. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings offer new and alternate sources with excellent biotechnological potential for digoxin production by fungal fermentation. Moreover, digoxin proved to be a promising anticancer agent whose anticancer potential should be assessed in prospective cancer therapy.


Assuntos
Antineoplásicos/metabolismo , Ascomicetos/genética , Ascomicetos/metabolismo , Digoxina/metabolismo , Animais , Antineoplásicos/farmacologia , Ascomicetos/isolamento & purificação , Ascomicetos/efeitos da radiação , Células CHO , Linhagem Celular Tumoral , Cricetulus , Digoxina/farmacologia , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Endófitos/efeitos da radiação , Fermentação , Raios gama , Humanos , Mutagênese , Filogenia
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