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1.
J Fungi (Basel) ; 10(6)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38921369

RESUMO

Current agrochemicals used in crop farming mainly consist of synthetic compounds with harmful effects on the environment and human health. Crop-associated fungal endophytes, which play many ecological roles including defense against pathogens, represent a promising source for bioactive and ecologically safer molecules in agrochemical discovery. The methanolic extract of the endophyte Menisporopsis sp. LCM 1078 was evaluated in vitro against the plant pathogens Boeremia exigua, Calonectria variabilis, Colletotrichum theobromicola, Colletotrichum tropicale, and Mycena cytricolor. Bioassay-guided isolation using chromatographic techniques followed by detailed chemical characterization by NMR and mass spectrometry led to the identification of menisporopsin A, which showed inhibitory activity in a dose-dependent manner against the five fungal pathogens including an endophytic strain (Colletotrichum tropicale), with MIC values in the range of 0.63-10.0 µg/mL showing a potency equivalent to the broadly employed agrochemical mancozeb.

2.
J Multimorb Comorb ; 14: 26335565231224570, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38186670

RESUMO

This is a descriptive study using healthcare claims data from patients with T2DM from public and private healthcare insurance companies providing services in Puerto Rico in 2013, aimed to estimate the prevalence of comorbidities in this population. Descriptive analyses were performed by sociodemographic, and type of service variables using frequency and percent for categorical data or means (+/-SD) or median (IQR) for continuous variables. Chi-square, Fisher exact or two-sample t-tests were used for comparisons. A total of 3,100,636 claims were identified from 485,866 adult patients with T2DM. Patients older than 65 years represented 48% of the study population. Most patients were women (57%) and had private health insurance (77%). The regions of Metro Area (17%) and Caguas (16%) had the higher number of persons living with T2DM. The overall estimated prevalence of T2DM was 17.4%. The number of claims per patient ranged from 1 to 339. A mean of 6.3 claims (SD±9.99) and a median of 3 claims (Q1 1- Q3 8) per subject were identified. Of the 3,100,636 claims most (74%) were related to the diagnosis of diabetes (59%) and associated to outpatient services (88%). The most prevalent comorbidities were hypertension (48%), hyperlipidemia (41%), neuropathy (21%); renal disease (15%), and retinopathy (13%). A high prevalence and co-prevalence of comorbidities and use of healthcare services were identified in patients with T2DM, especially in older adults. Since most comorbidities were due to diabetes-related conditions, this analysis highlights the importance of early diagnosis and adequate management of T2DM patients to avoid preventable burden to the patient and to the healthcare system.

3.
Microorganisms ; 10(11)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36363784

RESUMO

Mangrove ecosystems are threatened worldwide by a wide range of factors including climate change, coastal development, and pollution. The effects of these factors on soil bacterial communities of Neotropical mangroves and their temporal dynamics is largely undocumented. Here we compared the diversity and taxonomic composition of bacterial communities in the soil of two mangrove forest sites of the Panama Bay: Juan Diaz (JD), an urban mangrove forest in Panama City surrounded by urban development, with occurrence of five mangrove species, and polluted with solid waste and sewage; and Bayano (B), a rural mangrove forest without urban development, without solid waste pollution, and with the presence of two mangrove species. Massive amplicon sequencing of the V4 region of the 16S rRNA gene and community analyses were implemented. In total, 20,691 bacterial amplicon sequence variants were identified, and the bacterial community was more diverse in the rural mangrove forest based on Faith's phylogenetic diversity index. The three dominant phyla of bacteria found and shared between the two sites were Proteobacteria, Desulfobacterota, and Chloroflexi. The ammonia oxidizing archaea class Nitrosphaeria was found among the top 10 most abundant. Dominant genera of bacteria that occurred in the two mangrove sites were: BD2-11_terrestrial_group (Gemmatimonadota), EPR3968-O8a-Bc78 (Gammaproteobacteria), Salinimicrobium (Bacteroidetes), Sulfurovum (Campylobacteria), and Woeseia (Gammaproteobacteria) of which the first three and Methyloceanibacter had increased in relative abundance in the transition from rainy to dry to rainy season in the urban mangrove forest. Altogether, our study suggests that factors such as urban development, vegetation composition, pollution, and seasonal changes may cause shifts in bacterial diversity and relative abundance of specific taxa in mangrove soils. In particular, taxa with roles in biogeochemical cycles of carbon, nitrogen, sulfur, and phosphorus, and on rhizosphere taxa, could be important for mangrove plant resilience to environmental stress.

4.
Phytopathology ; 112(3): 643-652, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34428920

RESUMO

Hemileia vastatrix is the most important fungal pathogen of coffee and the causal agent of recurrent disease epidemics that have invaded nearly every coffee growing region in the world. The development of coffee varieties resistant to H. vastatrix requires fundamental understanding of the biology of the fungus. However, the complete life cycle of H. vastatrix remains unknown, and conflicting studies and interpretations exist as to whether the fungus is undergoing sexual reproduction. Here we used population genetics of H. vastatrix to infer the reproductive mode of the fungus across most of its geographic range, including Central Africa, Southeast Asia, the Caribbean, and South and Central America. The population structure of H. vastatrix was determined via eight simple sequence repeat markers developed for this study. The analyses of the standardized index of association, Hardy-Weinberg equilibrium, and clonal richness all strongly support asexual reproduction of H. vastatrix in all sampled areas. Similarly, a minimum spanning network tree reinforces the interpretation of clonal reproduction in the sampled H. vastatrix populations. These findings may have profound implications for resistance breeding and management programs against H. vastatrix.


Assuntos
Basidiomycota , Coffea , Basidiomycota/genética , Coffea/microbiologia , Café , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Reprodução Assexuada
5.
Artigo em Inglês | MEDLINE | ID: mdl-34948592

RESUMO

Early in the SARS-CoV-2 pandemic, many national public health authorities implemented non-pharmaceutical interventions to mitigate disease outbreaks. Panamá established mandatory mask use two months after its first documented case. Initial compliance was high, but diverse masks were used in public areas. We studied behavioral dynamics of mask use through the first two COVID-19 waves in Panama, to improve the implementation of effective, low-cost public health containment measures when populations are exposed to novel air-borne pathogens. Mask use behavior was recorded from pedestrians in four Panamanian populations (August to December 2020). We recorded facial coverings and if used, the type of mask, and gender and estimated age of the wearer. Our results showed that people were highly compliant (>95%) with mask mandates and demonstrated important population-level behaviors: (1) decreasing use of cloth masks over time, and increasing use of surgical masks; (2) mask use was 3-fold lower in suburban neighborhoods than other public areas and (3) young people were least likely to wear masks. Results help focus on highly effective, low-cost, public health interventions for managing and controlling a pandemic. Considerations of behavioral preferences for different masks, relative to pricing and availability, are essential for optimizing public health policies. Policies to increase the availability of effective masks, and behavioral nudges to increase acceptance, and to facilitate mask usage, during the ongoing SARS-CoV-2 pandemic, and for future pandemics of respiratory pathogens, are key tools, especially for nations lagging in access to expensive vaccines and pharmacological approaches.


Assuntos
COVID-19 , SARS-CoV-2 , Adolescente , Humanos , Máscaras , Pandemias , Saúde Pública
6.
PLoS Negl Trop Dis ; 14(10): e0008849, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33108372

RESUMO

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry is an analytical method that detects macromolecules that can be used for proteomic fingerprinting and taxonomic identification in arthropods. The conventional MALDI approach uses fresh laboratory-reared arthropod specimens to build a reference mass spectra library with high-quality standards required to achieve reliable identification. However, this may not be possible to accomplish in some arthropod groups that are difficult to rear under laboratory conditions, or for which only alcohol preserved samples are available. Here, we generated MALDI mass spectra of highly abundant proteins from the legs of 18 Neotropical species of adult field-collected hard ticks, several of which had not been analyzed by mass spectrometry before. We then used their mass spectra as fingerprints to identify each tick species by applying machine learning and pattern recognition algorithms that combined unsupervised and supervised clustering approaches. Both Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) classification algorithms were able to identify spectra from different tick species, with LDA achieving the best performance when applied to field-collected specimens that did have an existing entry in a reference library of arthropod protein spectra. These findings contribute to the growing literature that ascertains mass spectrometry as a rapid and effective method to complement other well-established techniques for taxonomic identification of disease vectors, which is the first step to predict and manage arthropod-borne pathogens.


Assuntos
Ixodidae/química , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Vetores de Doenças/classificação , Ixodidae/classificação , Ixodidae/metabolismo
7.
Insects ; 11(9)2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32878094

RESUMO

Insects host a highly diverse microbiome, which plays a crucial role in insect life. However, the composition and diversity of microbiomes associated with Neotropical freshwater insects is virtually unknown. In addition, the extent to which diversification of this microbiome is associated with host phylogenetic divergence remains to be determined. Here, we present the first comprehensive analysis of bacterial communities associated with six closely related species of Neotropical water striders in Panama. We used comparative phylogenetic analyses to assess associations between dominant bacterial linages and phylogenetic divergence among species of water striders. We found a total of 806 16S rRNA amplicon sequence variants (ASVs), with dominant bacterial taxa belonging to the phyla Proteobacteria (76.87%) and Tenericutes (19.51%). Members of the α- (e.g., Wolbachia) and γ- (e.g., Acinetobacter, Serratia) Proteobacteria, and Mollicutes (e.g., Spiroplasma) were predominantly shared across species, suggesting the presence of a core microbiome in water striders. However, some bacterial lineages (e.g., Fructobacillus, Fluviicola and Chryseobacterium) were uniquely associated with different water strider species, likely representing a distinctive feature of each species' microbiome. These findings indicate that both host identity and environmental context are important drivers of microbiome diversity in water striders. In addition, they suggest that diversification of the microbiome is associated with diversification in water striders. Although more research is needed to establish the evolutionary consequences of host-microbiome interaction in water striders, our findings support recent work highlighting the role of bacterial community host-microbiome codiversification.

8.
Mar Drugs ; 18(9)2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32899199

RESUMO

The marine bacterial genus Pseudoalteromonas is known for their ability to produce antimicrobial compounds. The metabolite-producing capacity of Pseudoalteromonas has been associated with strain pigmentation; however, the genomic basis of their antimicrobial capacity remains to be explained. In this study, we sequenced the whole genome of six Pseudoalteromonas strains (three pigmented and three non-pigmented), with the purpose of identifying biosynthetic gene clusters (BGCs) associated to compounds we detected via microbial interactions along through MS-based molecular networking. The genomes were assembled and annotated using the SPAdes and RAST pipelines and mined for the identification of gene clusters involved in secondary metabolism using the antiSMASH database. Nineteen BGCs were detected for each non-pigmented strain, while more than thirty BGCs were found for two of the pigmented strains. Among these, the groups of genes of nonribosomal peptide synthetases (NRPS) that code for bromoalterochromides stand out the most. Our results show that all strains possess BGCs for the production of secondary metabolites, and a considerable number of distinct polyketide synthases (PKS) and NRPS clusters are present in pigmented strains. Furthermore, the molecular networking analyses revealed two new molecules produced during microbial interactions: the dibromoalterochromides D/D' (11-12).


Assuntos
Anti-Infecciosos , Proteínas de Bactérias/genética , Mineração de Dados , Depsipeptídeos/genética , Perfilação da Expressão Gênica , Pseudoalteromonas/genética , Transcriptoma , Animais , Antozoários/microbiologia , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Bases de Dados Genéticas , Depsipeptídeos/metabolismo , Depsipeptídeos/farmacologia , Regulação Bacteriana da Expressão Gênica , Redes Reguladoras de Genes , Família Multigênica , Panamá , Parques Recreativos , Filogenia , Pseudoalteromonas/metabolismo , Metabolismo Secundário
9.
Am J Bot ; 107(2): 219-228, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32072625

RESUMO

PREMISE: Interactions between fungal endophytes and their host plants present useful systems for identifying important factors affecting assembly of host-associated microbiomes. Here we investigated the role of secondary chemistry in mediating host affinity of asymptomatic foliar endophytic fungi using Psychotria spp. and Theobroma cacao (cacao) as hosts. METHODS: First, we surveyed endophytic communities in Psychotria species in a natural common garden using culture-based methods. Then we compared differences in endophytic community composition with differences in foliar secondary chemistry in the same host species, determined by liquid chromatography-tandem mass spectrometry. Finally, we tested how inoculation with live and heat-killed endophytes affected the cacao chemical profile. RESULTS: Despite sharing a common environment and source pool for endophyte spores, different Psychotria host species harbored strikingly different endophytic communities that reflected intrinsic differences in their leaf chemical profiles. In T. cacao, inoculation with live and heat-killed endophytes produced distinct cacao chemical profiles not found in uninoculated plants or pure fungal cultures, suggesting that endophytes, like pathogens, induce changes in secondary chemical profiles of their host plant. CONCLUSIONS: Collectively our results suggest at least two potential processes: (1) Plant secondary chemistry influences assembly and composition of fungal endophytic communities, and (2) host colonization by endophytes subsequently induces changes in the host chemical landscape. We propose a series of testable predictions based on the possibility that reciprocal chemical interactions are a general property of plant-endophyte interactions.


Assuntos
Cacau , Fungos , Endófitos , Folhas de Planta , Plantas
10.
PLoS Biol ; 17(11): e3000533, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710600

RESUMO

The significance of symbioses between eukaryotic hosts and microbes extends from the organismal to the ecosystem level and underpins the health of Earth's most threatened marine ecosystems. Despite rapid growth in research on host-associated microbes, from individual microbial symbionts to host-associated consortia of significantly relevant taxa, little is known about their interactions with the vast majority of marine host species. We outline research priorities to strengthen our current knowledge of host-microbiome interactions and how they shape marine ecosystems. We argue that such advances in research will help predict responses of species, communities, and ecosystems to stressors driven by human activity and inform future management strategies.


Assuntos
Organismos Aquáticos/microbiologia , Microbiota/fisiologia , Simbiose/fisiologia , Animais , Bactérias/classificação , Ecossistema , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos
11.
BMC Chem ; 13(1): 22, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31384771

RESUMO

BACKGROUND: Mangroves plants and their endophytes represent a natural source of novel and bioactive compounds. In our ongoing research on mangrove endophytes from the Panamanian Pacific Coast, we have identified several bioactive endophytic fungi. From these organisms, an isolate belonging to the genus Zasmidium (Mycosphaerellaceae) showed 91.3% of inhibition against α-glucosidase enzyme in vitro. RESULTS: Zasmidium sp. strain EM5-10 was isolated from mature leaves of Laguncularia racemosa, and its crude extract showed good inhibition against α-glucosidase enzyme (91.3% of inhibition). Bioassay-guided fractionation of the crude extract led to obtaining two active fractions: L (tripalmitin) and M (Fungal Tryglicerides Mixture). Tripalmitin (3.75 µM) showed better inhibitory activity than acarbose (positive control, IC50 217.71 µM). Kinetic analysis established that tripalmitin acted as a mixed inhibitor. Molecular docking and molecular dynamics simulations predicted that tripalmitin binds at the same site as acarbose and also to an allosteric site in the human intestinal α-glucosidase (PDB: 3TOP). CONCLUSIONS: Zasmidium sp. strain EM5-10 represents a new source of bioactive substances that could possess beneficial properties for human health.

12.
J Basic Microbiol ; 58(9): 747-769, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29938809

RESUMO

Pseudoalteromonas is a genus of marine bacteria often found in association with other organisms. Although several studies have examined Pseudoalteromonas diversity and their antimicrobial activity, its diversity in tropical environments is largely unexplored. We investigated the diversity of Pseudoalteromonas in marine environments of Panama using a multilocus phylogenetic approach. Furthermore we tested their antimicrobial capacity and evaluated the effect of recombination and mutation in shaping their phylogenetic relationships. The reconstruction of clonal relationships among 78 strains including 15 reference Pseudoalteromonas species revealed 43 clonal lineages, divided in pigmented and non-pigmented strains. In total, 39 strains displayed moderate to high activity against Gram-positive and Gram-negative bacteria and fungi. Linkage disequilibrium analyses showed that the Pseudoalteromonas strains of Panama have a highly clonal structure and that, although present, recombination is not frequent enough to break the association among alleles. This clonal structure is in contrast to the high rates of recombination generally reported for aquatic and marine bacteria. We propose that this structure is likely due to the symbiotic association with marine invertebrates of most strains analyzed. Our results also show that there are several putative new species of Pseudoalteromonas in Panama to be described.


Assuntos
Anti-Infecciosos/metabolismo , Biodiversidade , Filogenia , Pseudoalteromonas/classificação , Pseudoalteromonas/genética , Água do Mar/microbiologia , Anti-Infecciosos/farmacologia , Análise por Conglomerados , DNA Bacteriano/genética , Genoma Bacteriano/genética , Desequilíbrio de Ligação , Panamá , Pseudoalteromonas/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
13.
Sci Rep ; 7(1): 5604, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28717220

RESUMO

The fungus-growing ant-microbe symbiosis is an ideal system to study chemistry-based microbial interactions due to the wealth of microbial interactions described, and the lack of information on the molecules involved therein. In this study, we employed a combination of MALDI imaging mass spectrometry (MALDI-IMS) and MS/MS molecular networking to study chemistry-based microbial interactions in this system. MALDI IMS was used to visualize the distribution of antimicrobials at the inhibition zone between bacteria associated to the ant Acromyrmex echinatior and the fungal pathogen Escovopsis sp. MS/MS molecular networking was used for the dereplication of compounds found at the inhibition zones. We identified the antibiotics actinomycins D, X2 and X0ß, produced by the bacterium Streptomyces CBR38; and the macrolides elaiophylin, efomycin A and efomycin G, produced by the bacterium Streptomyces CBR53.These metabolites were found at the inhibition zones using MALDI IMS and were identified using MS/MS molecular networking. Additionally, three shearinines D, F, and J produced by the fungal pathogen Escovopsis TZ49 were detected. This is the first report of elaiophylins, actinomycin X0ß and shearinines in the fungus-growing ant symbiotic system. These results suggest a secondary prophylactic use of these antibiotics by A. echinatior because of their permanent production by the bacteria.


Assuntos
Antibacterianos/farmacologia , Formigas/microbiologia , Interações Hospedeiro-Patógeno , Hypocreales/metabolismo , Streptomyces/metabolismo , Simbiose , Espectrometria de Massas em Tandem/métodos , Animais , Hypocreales/efeitos dos fármacos , Processamento de Imagem Assistida por Computador , Filogenia , Streptomyces/efeitos dos fármacos
14.
Proc Biol Sci ; 284(1858)2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28679727

RESUMO

It is increasingly recognized that microbiota affect host health and physiology. However, it is unclear what factors shape microbiome community assembly in nature, and how microbiome assembly can be manipulated to improve host health. All plant leaves host foliar endophytic fungi, which make up a diverse, environmentally acquired fungal microbiota. Here, we experimentally manipulated assembly of the cacao tree (Theobroma cacao) fungal microbiome in nature and tested the effect of assembly outcome on host health. Using next-generation sequencing, as well as culture-based methods coupled with Sanger sequencing, we found that manipulating leaf litter exposure and location within the forest canopy significantly altered microbiome composition in cacao. Exposing cacao seedlings to leaf litter from healthy conspecific adults enriched the seedling microbiome with Colletotrichum tropicale, a fungal endophyte known to enhance pathogen resistance of cacao seedlings by upregulating host defensive pathways. As a result, seedlings exposed to healthy conspecific litter experienced reduced pathogen damage. Our results link processes that affect the assembly and composition of microbiome communities to their functional consequences for host success, and have broad implications for understanding plant-microbe interactions. Deliberate manipulation of the plant-fungal microbiome also has potentially important applications for cacao production and other agricultural systems in general.


Assuntos
Cacau/microbiologia , Fungos , Microbiota , Folhas de Planta/microbiologia , Plântula/microbiologia
16.
BMC Genomics ; 17: 363, 2016 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-27189060

RESUMO

BACKGROUND: The pathogenesis-related (PR) group of proteins are operationally defined as polypeptides that increase in concentration in plant tissues upon contact with a pathogen. To date, 17 classes of highly divergent proteins have been described that act through multiple mechanisms of pathogen resistance. Characterizing these families in cacao, an economically important tree crop, and comparing the families to those in other species, is an important step in understanding cacao's immune response. RESULTS: Using publically available resources, all members of the 17 recognized pathogenesis-related gene families in the genome of Theobroma cacao were identified and annotated resulting in a set of ~350 members in both published cacao genomes. Approximately 50 % of these genes are organized in tandem arrays scattered throughout the genome. This feature was observed in five additional plant taxa (three dicots and two monocots), suggesting that tandem duplication has played an important role in the evolution of the PR genes in higher plants. Expression profiling captured the dynamics and complexity of PR genes expression at basal levels and after induction by two cacao pathogens (the oomycete, Phytophthora palmivora, and the fungus, Colletotrichum theobromicola), identifying specific genes within families that are more responsive to pathogen challenge. Subsequent qRT-PCR validated the induction of several PR-1, PR-3, PR-4, and PR-10 family members, with greater than 1000 fold induction detected for specific genes. CONCLUSIONS: We describe candidate genes that are likely to be involved in cacao's defense against Phytophthora and Colletotrichum infection and could be potentially useful for marker-assisted selection for breeding of disease resistant cacao varieties. The data presented here, along with existing cacao-omics resources, will enable targeted functional genetic screening of defense genes likely to play critical functions in cacao's defense against its pathogens.


Assuntos
Cacau/genética , Perfilação da Expressão Gênica , Genes de Plantas/genética , Análise de Sequência com Séries de Oligonucleotídeos , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Cacau/microbiologia , Cacau/parasitologia , Colletotrichum/fisiologia , Phytophthora/fisiologia , Doenças das Plantas/genética
17.
IMA Fungus ; 6(1): 145-54, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26203420

RESUMO

In advancing to one name for fungi, this paper treats generic names competing for use in the order Diaporthales (Ascomycota, Sordariomycetes) and makes a recommendation for the use or protection of one generic name among synonymous names that may be either sexually or asexually typified. A table is presented that summarizes these recommendations. Among the genera most commonly encountered in this order, Cytospora is recommended over Valsa and Diaporthe over Phomopsis. New combinations are introduced for the oldest epithet of important species in the recommended genus. These include Amphiporthe tiliae, Coryneum lanciforme, Cytospora brevispora, C. ceratosperma, C. cinereostroma, C. eugeniae, C. fallax, C. myrtagena, Diaporthe amaranthophila, D. annonacearum, D. bougainvilleicola, D. caricae-papayae, D. cocoina, D. cucurbitae, D. juniperivora, D. leptostromiformis, D. pterophila, D. theae, D. vitimegaspora, Mastigosporella georgiana, Pilidiella angustispora, P. calamicola, P. pseudogranati, P. stromatica, and P. terminaliae.

18.
Front Microbiol ; 5: 479, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25309519

RESUMO

It is increasingly recognized that macro-organisms (corals, insects, plants, vertebrates) consist of both host tissues and multiple microbial symbionts that play essential roles in their host's ecological and evolutionary success. Consequently, identifying benefits and costs of symbioses, as well as mechanisms underlying them are research priorities. All plants surveyed under natural conditions harbor foliar endophytic fungi (FEF) in their leaf tissues, often at high densities. Despite producing no visible effects on their hosts, experiments have nonetheless shown that FEF reduce pathogen and herbivore damage. Here, combining results from three genomic, and two physiological experiments, we demonstrate pervasive genetic and phenotypic effects of the apparently asymptomatic endophytes on their hosts. Specifically, inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant FEF species in healthy T. cacao, induces consistent changes in the expression of hundreds of host genes, including many with known defensive functions. Further, E+ plants exhibited increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes. These phenotypic changes observed in E+ plants correspond to changes in expression of specific functional genes in related pathways. Moreover, a cacao gene (Tc00g04254) highly up-regulated by C. tropicale also confers resistance to pathogen damage in the absence of endophytes or their products in host tissues. Thus, the benefits of increased pathogen resistance in E+ plants are derived in part from up-regulation of intrinsic host defense responses, and appear to be offset by potential costs including reduced photosynthesis, altered host nitrogen metabolism, and endophyte heterotrophy of host tissues. Similar effects are likely in most plant-endophyte interactions, and should be recognized in the design and interpretation of genetic and phenotypic studies of plants.

19.
Mycologia ; 103(2): 379-99, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21415292

RESUMO

The phylogeny of Cryptosporella is revised to include recently discovered species. Eight species new to science are described and two new combinations are proposed, raising the total number of species accepted in Cryptosporella to 19. The species delimitation and phylogeny for Cryptosporella are determined based on analyses of DNA sequences from three genes (ß-tubulin, ITS and tef1-α), comparative morphology of sexual structures on their host substrate, and host associations. The inferred phylogeny suggests that Cryptosporella has speciated primarily on Betulaceae with 16 species occurring on hosts in that plant family. The host range of most species seems to be narrow with nine species reported from a single host species or subspecies and seven species occurring on plants within a single host genus. A key to species is provided. The known distribution of Cryptosporella is expanded to mountain cloud forests of the provinces of Chiriquí in Panama and Tucumán in Argentina.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Especificidade de Hospedeiro , Filogenia , Plantas/microbiologia , Ascomicetos/genética , Ascomicetos/fisiologia , DNA Fúngico/genética , Proteínas Fúngicas/genética , Dados de Sequência Molecular , Especificidade da Espécie , Tubulina (Proteína)/genética
20.
Mycologia ; 100(5): 760-75, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18959162

RESUMO

A new lineage is discovered within the Botryosphaeriaceae (Ascomycetes, Dothideomycetes, incertae sedis). Consistent with current practice of providing generic names for independent lineages, this lineage is described as Endomelanconiopsis gen. nov., with the anamorphic species E. endophytica sp. nov. and E. microspora comb. nov. (= Endomelanconium microsporum). Endomelanconiopsis is characterized by eustromatic conidiomata and holoblastically produced, brown, nonapiculate, unicellular conidia, each with a longitudinal germ slit. Phylogenetic analysis of partial sequences of LSU, ITS and translation elongation factor 1 alpha (tef1) indicate that E. endophytica is sister of E. microspora and that they are nested within the Botryosphaeriaceae. However because there is no support for the "backbone" of the Botryosphaeriacae we are not able to see the interrelationships among the many genera in the family. Neither species is known to have a teleomorph. Endomelanconiopsis differs from Endomelanconium because conidia of the type species of Endomelanconium, E. pini, are papillate at the base, conidiogenous cells proliferate sympodially and the pycnidial wall is thinner; we postulate that the teleomorph of E. pini as yet unknown is an inoperculate discomycete. Endomelanconiopsis endophytica was isolated as an endophyte from healthy leaves of Theobroma cacao (cacao, Malvaceae) and Heisteria concinna (Erythroplaceae) in Panama. Endomelanconiopsis microspora was isolated from soil in Europe.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Ascomicetos/citologia , Ascomicetos/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Proteínas Fúngicas/genética , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos/genética , Filogenia , Microbiologia do Solo , Esporos Fúngicos/citologia
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