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1.
Int J Syst Evol Microbiol ; 70(10): 5355-5362, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32881677

RESUMO

Two novel strains (HMF3257T and HMF4905T), isolated from freshwater and bark samples, were investigated to determine their relationships within and between species of the genus Spirosoma by using a polyphasic approach. They were aerobic, Gram-stain-negative, non-motile and rod-shaped bacteria. The major fatty acids (>10%) in both strains were identified as summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 1 ω5c, while strains HMF3257T and HMF4905T contained a moderately high amount of C16 : 0 and iso-C15 : 0, respectively. The predominant respiratory quinone was MK-7 for both strains. In addition to phosphatidylethanolamine and one unidentified glycolipid, the polar lipid profile of strain HMF3257T consisted of three unidentified aminophospholipids, one unidentified aminolipid and two unidentified polar lipids, and that of strain HMF4905T consisted of one unidentified aminophospholipid, two unidentified aminolipids and three unidentified polar lipids. The DNA G+C contents of strains HMF3257T and HMF4905T were 47.2 and 46.4 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains HMF3257T and HMF4905T are closely related to Spirosoma migulaei 15J9-8T (97.0 % sequence similarity), while sharing 97.4 % sequence similarity with each other. The average nucleotide identity value between strains HMF3257T and HMF4905T was 81.1 %, and the digital DNA-DNA hybridization value between these two strains was 24.4 %. Based on the above data, strains HMF3257T and HMF4905T represent two novel members within the genus Spirosoma, for which the names Spirosoma telluris sp. nov. and Spirosoma arboris sp. nov. are proposed, respectively. The type strain of S. telluris is HMF3257T (=KCTC 62463T=NBRC 112670T) and type strain of S. arboris is HMF4905T (=KCTC 72779T=NBRC 114270T).


Assuntos
Cytophagaceae/classificação , Filogenia , Casca de Planta/microbiologia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Cytophagaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pinales/microbiologia , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Árvores/microbiologia , Vitamina K 2/análogos & derivados , Vitamina K 2/química
2.
Proc Biol Sci ; 287(1933): 20200956, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811286

RESUMO

Forest declines caused by climate disturbance, insect pests and microbial pathogens threaten the global landscape, and tree diseases are increasingly attributed to the emergent properties of complex ecological interactions between the host, microbiota and insects. To address this hypothesis, we combined reductionist approaches (single and polyspecies bacterial cultures) with emergentist approaches (bacterial inoculations in an oak infection model with the addition of insect larvae) to unravel the gene expression landscape and symptom severity of host-microbiota-insect interactions in the acute oak decline (AOD) pathosystem. AOD is a complex decline disease characterized by predisposing abiotic factors, inner bark lesions driven by a bacterial pathobiome, and larval galleries of the bark-boring beetle Agrilus biguttatus. We identified expression of key pathogenicity genes in Brenneria goodwinii, the dominant member of the AOD pathobiome, tissue-specific gene expression profiles, cooperation with other bacterial pathobiome members in sugar catabolism, and demonstrated amplification of pathogenic gene expression in the presence of Agrilus larvae. This study highlights the emergent properties of complex host-pathobiota-insect interactions that underlie the pathology of diseases that threaten global forest biomes.


Assuntos
Gammaproteobacteria , Interações entre Hospedeiro e Microrganismos , Doenças das Plantas/microbiologia , Árvores/microbiologia , Animais , Besouros , Microbiota , Quercus/microbiologia
3.
Nat Commun ; 11(1): 4024, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788652

RESUMO

Soil microbial communities remain active during much of the Arctic winter, despite deeply frozen soils. Overwinter microbial activity affects the global carbon (C) budget, nutrient cycling, and vegetation composition. Microbial respiration is highly temperature sensitive in frozen soils, as liquid water and solute availability decrease rapidly with declining temperature. Climate warming and changes in snowpack are leading to warmer Arctic winter soils. Warmer winter soils are thought to yield greater microbial respiration of available C, greater overwinter CO2 efflux and greater nutrient availability to plants at thaw. Using field and laboratory observations and experiments, we demonstrate that persistently warm winter soils can lead to labile C starvation and reduced microbial respiration, despite the high C content of most Arctic soils. If winter soils continue to warm, microbial C limitation will reduce expected CO2 emissions and alter soil nutrient cycling, if not countered by greater labile C inputs.


Assuntos
Carbono , Microbiota/fisiologia , Estações do Ano , Microbiologia do Solo , Solo/química , Árvores/microbiologia , Alaska , Regiões Árticas , Atmosfera , Ciclo do Carbono , Dióxido de Carbono , Mudança Climática , Ecossistema , Glucose/metabolismo , Modelos Teóricos , Plantas , Temperatura
4.
PLoS One ; 15(7): e0235932, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645087

RESUMO

We tested whether post-fire seedling establishment of common boreal tree and expanding shrub species at treeline and in Arctic tundra is facilitated by co-migration of boreal forest mycorrhizal fungi. Wildfires are anticipated to facilitate biome shifts at the forest-tundra ecotone by improving seedbed conditions for recruiting boreal species; at the same time fire alters the composition and availability of mycorrhizal fungi critical to seedling performance. To determine the role of root-associated fungi (RAF) in post-fire seedling recruitment and future biome shifts, we outplanted four dominant boreal tree and shrub species inoculated with one of three treatments at treeline and in tundra: burned boreal forest, unburned boreal forest, or a control treatment of sterilized inoculum. We compared survivorship, growth, and physiological performance of the seedlings in relation to mycorrhizal inoculum treatment and among host species, characterized the RAF communities based on ITS-rDNA sequencing of individual root tips sampled from surviving seedlings, and tested for correlations between RAF composition and the inoculation treatments, host species, and duration of the experiment. We explored correlations between RAF composition and seedling metrics. Both live and sterile autoclaved inoculation treatments had similar effects on seedling survivorship and growth for all species. RAF composition did not vary by treatment, suggesting that most colonization was due to local fungi. However, seedling traits and growth were correlated with RAF species composition, colonization, and the relative abundance of specific RAF taxa. Picea sp. performance in particular showed strong co-variation with RAF metrics. Our results suggest that mycorrhizal co-migration is not a primary limiting factor to boreal seedling recruitment because the experimental provision of inoculum did not affect seedling recruitment; yet, RAF did influence seedling performance, particularly resident RAF at treeline and in tundra, suggesting that mycorrhizal fungi are important to vegetation processes at the treeline-tundra ecotone.


Assuntos
Micorrizas/fisiologia , Árvores/microbiologia , Incêndios Florestais , Basidiomycota/fisiologia , Picea/crescimento & desenvolvimento , Picea/microbiologia , Raízes de Plantas/microbiologia , Populus/crescimento & desenvolvimento , Populus/microbiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Especificidade da Espécie , Taiga , Árvores/crescimento & desenvolvimento , Tundra
5.
Nat Commun ; 11(1): 2636, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32457288

RESUMO

The mechanisms regulating community composition and local dominance of trees in species-rich forests are poorly resolved, but the importance of interactions with soil microbes is increasingly acknowledged. Here, we show that tree seedlings that interact via root-associated fungal hyphae with soils beneath neighbouring adult trees grow faster and have greater survival than seedlings that are isolated from external fungal mycelia, but these effects are observed for species possessing ectomycorrhizas (ECM) and not arbuscular mycorrhizal (AM) fungi. Moreover, survival of naturally-regenerating AM seedlings over ten years is negatively related to the density of surrounding conspecific plants, while survival of ECM tree seedlings displays positive density dependence over this interval, and AM seedling roots contain greater abundance of pathogenic fungi than roots of ECM seedlings. Our findings show that neighbourhood interactions mediated by beneficial and pathogenic soil fungi regulate plant demography and community structure in hyperdiverse forests.


Assuntos
Micorrizas/fisiologia , Microbiologia do Solo , Árvores/microbiologia , China , Florestas , Fungos/genética , Fungos/patogenicidade , Fungos/fisiologia , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/fisiologia , Modelos Biológicos , Biologia Molecular , Micorrizas/genética , Micorrizas/patogenicidade , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Simbiose , Árvores/crescimento & desenvolvimento
6.
PLoS One ; 15(4): e0226863, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240194

RESUMO

Global trade and climate change are responsible for a surge in foreign invasive species and emerging pests and pathogens across the world. Early detection and surveillance activities are essential to monitor the environment and prevent or mitigate future ecosystem impacts. Molecular diagnostics by DNA testing has become an integral part of this process. However, for environmental applications, there is a need for cost-effective and efficient point-of-use DNA testing to obtain accurate results from remote sites in real-time. This requires the development of simple and fast sample processing and DNA extraction, room-temperature stable reagents and a portable instrument. We developed a point-of-use real-time Polymerase Chain Reaction system using a crude buffer-based DNA extraction protocol and lyophilized, pre-made, reactions for on-site applications. We demonstrate the use of this approach with pathogens and pests covering a broad spectrum of known undesirable forest enemies: the fungi Sphaerulina musiva, Cronartium ribicola and Cronartium comandrae, the oomycete Phytophthora ramorum and the insect Lymantria dispar. We obtained positive DNA identification from a variety of different tissues, including infected leaves, pathogen spores, or insect legs and antenna. The assays were accurate and yielded no false positive nor negative. The shelf-life of the lyophilized reactions was confirmed after one year at room temperature. Finally, successful tests conducted with portable thermocyclers and disposable instruments demonstrate the suitability of the method, named in Situ Processing and Efficient Environmental Detection (iSPEED), for field testing. This kit fits in a backpack and can be carried to remote locations for accurate and rapid detection of pests and pathogens.


Assuntos
Monitoramento Ambiental , Fungos/isolamento & purificação , Espécies Introduzidas , Árvores/microbiologia , Mudança Climática , Ecossistema , Florestas , Fungos/genética , Fungos/patogenicidade , Humanos , Controle de Pragas/métodos , Reação em Cadeia da Polimerase , Árvores/genética , Árvores/crescimento & desenvolvimento
7.
Int J Syst Evol Microbiol ; 70(4): 2664-2676, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32238230

RESUMO

This study examined over 20 fungal specimens of the Orbiliaceae (Orbiliomycetes) from different regions in China. Our analyses based on morphological traits and the ITS rDNA sequences revealed two new Orbilia species with drechslerella-like asexual morphs. These new species are able to trap nematodes with constricting rings. In addition, Orbilia cf. orientalis is reported as a new cryptic Chinese variant of European collections of O. orientalis. All three species are described and illustrated in detail in this paper. Their phylogenetic relationships with other orbiliaceous species were identified based on their ITS sequences.


Assuntos
Ascomicetos/classificação , Filogenia , Árvores/microbiologia , Animais , Ascomicetos/isolamento & purificação , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Ácidos Graxos/química , Florestas , Técnicas de Tipagem Micológica , Nematoides/microbiologia , Análise de Sequência de DNA
8.
PLoS One ; 15(4): e0231215, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267901

RESUMO

Plants interact with a great variety of microorganisms that inhabit the rhizosphere or the epiphytic and endophytic phyllosphere and that play critical roles in plant growth as well as the biocontrol of phytopathogens and insect pests. Avocado fruit damage caused by the thrips species Scirtothrips perseae leads to economic losses of 12-51% in many countries. In this study, a screening of bacteria associated with the rhizosphere or endophytic phyllosphere of avocado roots was performed to identify bacterial isolates with plant growth-promoting activity in vitro assays with Arabidopsis seedlings and to assess the biocontrol activity of the isolates against Scirtothrips perseae. The isolates with beneficial, pathogenic and/or neutral effects on Arabidopsis seedlings were identified. The plant growth-promoting bacteria were clustered in two different groups (G1 and G3B) based on their effects on root architecture and auxin responses, particularly bacteria of the Pseudomonas genus (MRf4-2, MRf4-4 and TRf2-7) and one Serratia sp. (TS3-6). Twenty strains were selected based on their plant growth promotion characteristics to evaluate their potential as thrips biocontrol agents. Analyzing the biocontrol activity of S. perseae, it was identified that Chryseobacterium sp. shows an entomopathogenic effect on avocado thrips survival. Through the metabolic profiling of compounds produced by bacteria with plant growth promotion activity, bioactive cyclodipeptides (CDPs) that could be responsible for the plant growth-promoting activity in Arabidopsis were identified in Pseudomonas, Serratia and Stenotrophomonas. This study unravels the diversity of bacteria from the avocado rhizosphere and highlights the potential of a unique isolate to achieve the biocontrol of S. perseae.


Assuntos
Controle de Insetos/métodos , Persea/crescimento & desenvolvimento , Persea/microbiologia , Controle Biológico de Vetores/métodos , Tisanópteros/microbiologia , Árvores/crescimento & desenvolvimento , Árvores/microbiologia , Animais , Arabidopsis/fisiologia , Técnicas de Cocultura , DNA Bacteriano/genética , Ácidos Indolacéticos/metabolismo , Filogenia , Pseudomonas/metabolismo , Rizosfera , Plântula/metabolismo , Serratia/metabolismo , Stenotrophomonas/metabolismo
9.
Int J Syst Evol Microbiol ; 70(4): 2677-2681, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32207678

RESUMO

Six strains of a novel yeast species were isolated from tree bark collected in the Atlantic Forest and the Amazon Rainforest in Brazil. Analyses of the sequences of D1/D2 domains of the large subunit rRNA gene showed that the strains belong to a species in the genus Zygotorulaspora. The species differed by 5.54 % sequence divergence (25 substitutions and five indels out of 542 bp) in the D1/D2 sequences from Zygotorulaspora mrakii, its closest relative. The ITS sequence of the type strain of the novel species differs by 27-69 nucleotide substitutions/indels from the other Zygotorulaspora species. The novel species is able to grow on trehalose, maltose, l-sorbose, inulin and at 37 °C, which are negative in Z. mrakii. The name Zygotorulaspora cariocana sp. nov. is proposed. The holotype of Z. cariocana sp. nov. is CBS 16118T. The MycoBank number is MB 833702.


Assuntos
Filogenia , Casca de Planta/microbiologia , Saccharomycetales/classificação , Brasil , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Floresta Úmida , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA , Árvores/microbiologia
10.
Planta ; 251(4): 83, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32189086

RESUMO

MAIN CONCLUSION: Plant growth-promoting bacteria association improved the enzymatic and non-enzymatic antioxidant pathways in Neotropical trees under drought, which led to lower oxidative damage and enhanced drought tolerance in these trees. Water deficit is associated with oxidative stress in plant cells and may, thus, negatively affect the establishment of tree seedlings in reforestation areas. The association with plant growth-promoting bacteria (PGPB) is known to enhance the antioxidant response of crops, but this strategy has not been tested in seedlings of Neotropical trees. We evaluated the effects of inoculation with two PGPB (Azospirillum brasilense and Bacillus sp.) on the antioxidant metabolism of Cecropia pachystachya and Cariniana estrellensis seedlings submitted to drought. We measured the activity of antioxidant enzymes and the content of non-enzymatic antioxidants in leaves, and biometrical parameters of the seedlings. In both tree species, drought decreased the activity of antioxidant enzymes and the content of non-enzymatic antioxidant compounds. For C. pachystachya, the enzymatic and non-enzymatic pathways were mostly influenced by A. brasilense inoculation, which enhanced ascorbate peroxidase (APX) and superoxide dismutase activities and positively affected the level of non-enzymatic antioxidant compounds. In C. estrellensis, A. brasilense inoculation enhanced APX activity. However, A. brasilense and Bacillus sp. inoculation had more influence on the non-enzymatic pathway, as both bacteria induced a greater accumulation of secondary compounds (such as chlorogenic acid, gallic acid, rutin and synapic acid) compared to that in non-inoculated plants under drought. For both species, PGPB improved biometrical parameters related to drought tolerance, as specific leaf area and leaf-area ratio. Our results demonstrate that PGPB induced antioxidant mechanisms in drought-stressed Neotropical trees, increasing drought tolerance. Thus, PGPB inoculation provides a biotechnological alternative to improve the success of reforestation programmes.


Assuntos
Antioxidantes/metabolismo , Desenvolvimento Vegetal , Estresse Fisiológico , Árvores/metabolismo , Ascorbato Peroxidases/metabolismo , Azospirillum brasilense/metabolismo , Cecropia (Planta)/metabolismo , Cecropia (Planta)/microbiologia , Secas , Lecythidaceae/metabolismo , Lecythidaceae/microbiologia , Estresse Oxidativo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Plântula/metabolismo , Plântula/microbiologia , Árvores/microbiologia
11.
Sci Rep ; 10(1): 5310, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210276

RESUMO

Determining the impacts of invasive pathogens on tree mortality and growth is a difficult task, in particular in the case of species occurring naturally at low frequencies in mixed stands. In this study, we quantify such effects by comparing national forest inventory data collected before and after pathogen invasion. In Norway, Fraxinus excelsior is a minor species representing less than 1% of the trees in the forests and being attacked by the invasive pathogen Hymenoscyphus fraxineus since 2006. By studying deviations between inventories, we estimated a 74% higher-than-expected average ash mortality and a 13% slower-than-expected growth of the surviving ash trees, indicating a lack of compensation by the remaining ash. We could confidently assign mortality and growth losses to ash dieback as no mortality or growth shifts were observed for co-occurring tree species in the same plots. The mortality comparisons also show regional patterns with higher mortality in areas with the longest disease history in Norway. Considering that ash is currently mostly growing in mixed forests and that no signs of compensation were observed by the surviving ash trees, a significant habitat loss and niche replacement could be anticipated in the mid-term.


Assuntos
Ascomicetos/patogenicidade , Fraxinus/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Árvores/crescimento & desenvolvimento , Virulência , Biodiversidade , Fraxinus/microbiologia , Árvores/microbiologia
12.
Sci Rep ; 10(1): 2302, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041976

RESUMO

We observed strong positive relationships between soil properties and forest dynamics of growth and mortality across twelve primary lowland tropical forests in a phosphorus-poor region of the Guiana Shield. Average tree growth (diameter at breast height) increased from 0.81 to 2.1 mm yr-1 along a soil texture gradient from 0 to 67% clay, and increasing metal-oxide content. Soil organic carbon stocks in the top 30 cm ranged from 30 to 118 tons C ha-1, phosphorus content ranged from 7 to 600 mg kg-1 soil, and the relative abundance of arbuscular mycorrhizal fungi ranged from 0 to 50%, all positively correlating with soil clay, and iron and aluminum oxide and hydroxide content. In contrast, already low extractable phosphorus (Bray P) content decreased from 4.4 to <0.02 mg kg-1 in soil with increasing clay content. A greater prevalence of arbuscular mycorrhizal fungi in more clayey forests that had higher tree growth and mortality, but not biomass, indicates that despite the greater investment in nutrient uptake required, soils with higher clay content may actually serve to sustain high tree growth in tropical forests by avoiding phosphorus losses from the ecosystem. Our study demonstrates how variation in soil properties that retain carbon and nutrients can help to explain variation in tropical forest growth and mortality, but not biomass, by requiring niche specialization and contributing to biogeochemical diversification across this region.


Assuntos
Biomassa , Micorrizas/crescimento & desenvolvimento , Fósforo/análise , Solo/química , Árvores/crescimento & desenvolvimento , Carbono/análise , Carbono/metabolismo , Micorrizas/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Fósforo/metabolismo , Floresta Úmida , Microbiologia do Solo , Árvores/microbiologia , Clima Tropical
13.
Microbiol Res ; 235: 126440, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32109690

RESUMO

Although the use of crop-associated bacteria as biological control agents of fungal diseases has gained increasing interest, the biotechnological potential of forest tree-associated microbes and their natural products has scarcely been investigated. The objective of this study was to identify bacteria or bacterial products with antagonistic activity against Fusarium solani and Fusarium kuroshium, causal agent of Fusarium dieback, by screening the rhizosphere and phyllosphere of three Lauraceae species. From 195 bacterial isolates, we identified 32 isolates that significantly reduced the growth of F. solani in vitro, which mostly belonged to bacterial taxa Bacillus, Pseudomonas and Actinobacteria. The antifungal activity of their volatile organic compounds (VOCs) was also evaluated. Bacterial strain Bacillus sp. CCeRi1-002, recovered from the rhizosphere of Aiouea effusa, showed the highest percentage of direct inhibition (62.5 %) of F. solani and produced diffusible compounds that significantly reduced its mycelial growth. HPLC-MS analyses on this strain allowed to tentatively identify bioactive compounds from three lipopeptide groups (iturin, surfactin and fengycin). Bacillus sp. CCeRi1-002 and another strain identified as Pseudomonas sp. significantly inhibited F. solani mycelial growth through the emission of VOCs. Chemical analysis of their volatile profiles indicated the likely presence of 2-nonanone, 2-undecanone, disulfide dimethyl and 1-butanol 3-methyl-, which had been previously reported with antifungal activity. In antagonism assays against F. kuroshium, Bacillus sp. CCeRi1-002 and its diffusible compounds exhibited significant antifungal activity and induced hyphal deformations. Our findings highlight the importance of considering bacteria associated with forest species and the need to include bacterial products in the search for potential antagonists of Fusarium dieback.


Assuntos
Antibiose , Antifúngicos/farmacologia , Bactérias/química , Agentes de Controle Biológico/química , Fusarium/patogenicidade , Doenças das Plantas/prevenção & controle , Árvores/microbiologia , Florestas , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S , Rizosfera , Compostos Orgânicos Voláteis/química
14.
J Mycol Med ; 30(1): 100922, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31959581

RESUMO

BACKGROUND: To report a case of fungal keratitis caused by Colletotrichum gloeosporioides in an east coast city of China, which are rare pathogens that cause fungal keratitis in humans. METHODS: A 52-year-old man whose right eye was injured by a branch of an apple tree during farm work was referred to our Hospital. He was examined by Slit-lamp and the HRT II-RCM confocal scanning microscope, thus suggesting filamentous. Orneal scrapings were acquired and then inoculated into Sabouraud medium incubated at 28°C and 37°C. In vitro antifungal susceptibility tests were performed following the CLSI M38-A2 for Filamentous Fungi. Surgical intervention was advised because the abscess in the anterior chamber of the right eye was not completely absorbed. RESULTS: The Colletotrichum gloeosporioides isolate was identified by MALDI-TOF mass spectrometry and the BLAST after DNA sequencing of the amplified internal transcribed spacer (ITS) in rRNA. The patient's eye condition is under control and the patient's vision remains at the level of light perception (LP). CONCLUSIONS: We report the rare keratitis caused by C. gloeosporioides in eastern China, which has not been published. Suddenly ocular trauma and old surgical intervention may be the risk factors associated with Colletotrichum keratitis.


Assuntos
Colletotrichum/isolamento & purificação , Infecções Oculares Fúngicas/microbiologia , Ceratite/microbiologia , Antifúngicos/uso terapêutico , China , Colletotrichum/genética , Úlcera da Córnea/tratamento farmacológico , Úlcera da Córnea/microbiologia , Úlcera da Córnea/cirurgia , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/cirurgia , Traumatismos Oculares/complicações , Traumatismos Oculares/tratamento farmacológico , Traumatismos Oculares/microbiologia , Traumatismos Oculares/cirurgia , Humanos , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Ceratite/cirurgia , Masculino , Malus/microbiologia , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica/métodos , Análise de Sequência de DNA , Árvores/microbiologia
15.
Nat Commun ; 11(1): 286, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941904

RESUMO

A prominent tree species coexistence mechanism suggests host-specific natural enemies inhibit seedling recruitment at high conspecific density (negative conspecific density dependence). Natural-enemy-mediated conspecific density dependence affects numerous tree populations, but its strength varies substantially among species. Understanding how conspecific density dependence varies with species' traits and influences the dynamics of whole communities remains a challenge. Using a three-year manipulative community-scale experiment in a temperate forest, we show that plant-associated fungi, and to a lesser extent insect herbivores, reduce seedling recruitment and survival at high adult conspecific density. Plant-associated fungi are primarily responsible for reducing seedling recruitment near conspecific adults in ectomycorrhizal and shade-tolerant species. Insects, in contrast, primarily inhibit seedling recruitment of shade-intolerant species near conspecific adults. Our results suggest that natural enemies drive conspecific density dependence in this temperate forest and that which natural enemies are responsible depends on the mycorrhizal association and shade tolerance of tree species.


Assuntos
Florestas , Plântula/fisiologia , Árvores/fisiologia , Animais , China , Herbivoria , Insetos , Micorrizas , Árvores/microbiologia
16.
Nat Prod Res ; 34(1): 110-121, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31298589

RESUMO

Taxol is one of the anticancer drugs synthesized naturally in the evergreen Taxus brevifolia forest tree belonging to the yew family (Taxaceae) growing on the Pacific. There are reportedly evidence for treating ovarian, breast and lung cancers through this drug given its unique structural and functional features. Extraction of this drug from yew trees bark is one of the most common ways of producing this drug, but 3000 trees are needed to obtain a kilogram of Taxol. Hence, further attention has recently been attracted to the metabolic engineering strategies, including, engineering cellular metabolism of microorganisms and their optimization. Accordingly, the present paper article was aimed to review recent advances in elevating the production and commercialization of Taxol through metabolic engineering techniques.


Assuntos
Engenharia Metabólica/métodos , Paclitaxel/biossíntese , Taxus/química , Antineoplásicos Fitogênicos/biossíntese , Humanos , Neoplasias/tratamento farmacológico , Taxus/microbiologia , Árvores/microbiologia
17.
FEMS Microbiol Ecol ; 96(1)2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31665274

RESUMO

The microbial habitat on leaf surfaces, also called the phyllosphere, is a selective environment for bacteria, harbouring specific phyllosphere bacterial communities (PBCs). These communities influence plant health, plant-community diversity, ecosystem functioning and ecosystem services. Host plants in an urban environment accommodate different PBCs than those in non-urban environments, but previous studies did not address individual urban factors. In this study, the PBC composition and diversity of 55 London plane (Platanus x acerifolia) trees throughout an urban landscape (Antwerp, Belgium) were determined using 16S rRNA amplicon sequencing. An increasing proportion of green infrastructure in the surrounding of the trees, and subsequently decreasing proportion of anthropogenic land use, was linked with taxa loss, expressed in lower phyllosphere alpha diversity and higher abundances of typical phyllosphere bacteria such as Hymenobacter, Pseudomonas and Beijerinckia. Although air pollution exposure, as assessed by leaf magnetic analysis, did not link with alpha diversity, it correlated with shifts in PBC composition in form of turnover, an equilibrium of taxa gain and taxa loss. We found that both urban landscape composition and air pollution exposure - each in their own unique way - influence bacterial communities in the urban tree phyllosphere.


Assuntos
Poluição do Ar , Microbiota , Folhas de Planta/microbiologia , Urbanização , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bélgica , Biodiversidade , Ecossistema , RNA Ribossômico 16S/genética , Árvores/microbiologia
18.
Mol Ecol ; 29(1): 199-213, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31755612

RESUMO

The taxonomically diverse phyllosphere fungi inhabit leaves of plants. Thus, apart from the fungi's dispersal capacities and environmental factors, the assembly of the phyllosphere community associated with a given host plant depends on factors encoded by the host's genome. The host genetic factors and their influence on the assembly of phyllosphere communities under natural conditions are poorly understood, especially in trees. Recent work indicates that Norway spruce (Picea abies) vegetative buds harbour active fungal communities, but these are hitherto largely uncharacterized. This study combines internal transcribed spacer sequencing of the fungal communities associated with dormant vegetative buds with a genome-wide association study (GWAS) in 478 unrelated Norway spruce trees. The aim was to detect host loci associated with variation in the fungal communities across the population, and to identify loci correlating with the presence of specific, latent, pathogens. The fungal communities were dominated by known Norway spruce phyllosphere endophytes and pathogens. We identified six quantitative trait loci (QTLs) associated with the relative abundance of the dominating taxa (i.e., top 1% most abundant taxa). Three additional QTLs associated with colonization by the spruce needle cast pathogen Lirula macrospora or the cherry spruce rust (Thekopsora areolata) in asymptomatic tissues were detected. The identification of the nine QTLs shows that the genetic variation in Norway spruce influences the fungal community in dormant buds and that mechanisms underlying the assembly of the communities and the colonization of latent pathogens in trees may be uncovered by combining molecular identification of fungi with GWAS.


Assuntos
Ascomicetos/genética , Basidiomycota/genética , Estudo de Associação Genômica Ampla , Micobioma , Picea/genética , Locos de Características Quantitativas/genética , Ecologia , Endófitos , Genótipo , Noruega , Fenótipo , Picea/microbiologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Árvores/microbiologia
19.
J Mycol Med ; 30(1): 100917, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864801

RESUMO

OBJECTIVE: Limited data are available on the epidemiology and etiology of cryptococcal infections in the Middle East. We aimed to conduct the systematic review and meta-analysis to summarize the epidemiological data on prevalence of Cryptococcus species complexes in trees and their surroundings, bird guano and secretions, animals, and highlight the reported episodes of cryptococcosis in Iran. MATERIALS AND METHODS: Twelve databases, including PubMed, Science Direct, Scopus, Proquest, Google Scholar, Embase, and the ISI Web of Science, as well as the national databases, from January 1969 to October 2019 were searched. Furthermore, gray literature (e.g., thesis, congress abstracts) was evaluated using Iran Doc and www.thesis. RESEARCH: ac.ir. Search process was accomplished on English or Persian language articles using the following keywords: "Cryptococcus", "Cryptococcosis", "invasive fungal infection", "Humans", "Birds", "Pigeon", "Animals", "Tree", "Eucalyptus", and "Iran", both alone and in combination. RESULTS: Overall 36 studies were eligible regarding Cryptococcus and cryptococcosis in Iran. The total prevalence rates of Cryptococcus species in the tree was 4.7% (95% CI: 2.3-7.8), and in bird guano was 20.4% (95% CI: 10.7-32.2). Cryptococcosis in animal, and human were 1.7% (95% CI: 0.01-5.1), and 2.8% (95% CI: 0.7v6.1), respectively. The highest prevalence of Cryptococcus in the trees (14.6%), and bird guano (89.4%) in Khorasan, animals (8.9%) in Chaharmahal and Bakhtiari, and human (4.4%) in Mazandaran provinces were reported. CONCLUSIONS: Given the significant risk of Cryptococcus species for susceptible humans, mainly HIV-infected patients, it seems quite necessary to adopt concrete preventive strategies to pinpoint the environmental habitats of this yeast.


Assuntos
Criptococose/epidemiologia , Criptococose/microbiologia , Cryptococcus/classificação , Cryptococcus/isolamento & purificação , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/microbiologia , Columbidae/microbiologia , Criptococose/veterinária , Eucalyptus/microbiologia , Humanos , Infecções Fúngicas Invasivas/epidemiologia , Infecções Fúngicas Invasivas/microbiologia , Irã (Geográfico)/epidemiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/estatística & dados numéricos , Prevalência , Árvores/microbiologia
20.
FEMS Microbiol Ecol ; 96(2)2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31825516

RESUMO

Despite numerous studies on plant endophytes, little is known about fungal communities associated with different aboveground tissues of living trees. We used high-throughput sequencing to compare the diversity and community structure of fungi inhabiting leaves, branches and trunks of Alnus incana and Corylus avellana growing at three hemiboreal forest sites. Our analysis revealed that tree organs are the main determinants of the structure of fungal communities, whereas the effects of host species and locality remained secondary and negligible, respectively. The structure of fungal communities in trunks was the most distinct compared to that in leaves and branches. The foliar fungal communities were more similar within than between individual trees, implying that certain fungi may grow through parts of the tree crown. The weak effect of locality compared to host organs and species identity suggests that the structural variation of fungal communities in the aboveground parts of trees depends mainly on deterministic factors rather than dispersal limitation.


Assuntos
Florestas , Micobioma/genética , Árvores/microbiologia , Biodiversidade , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Especificidade de Hospedeiro , Componentes Aéreos da Planta/microbiologia , Árvores/anatomia & histologia , Árvores/classificação
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