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1.
Ecol Lett ; 23(2): 409-411, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31898406

RESUMO

Whether natural selection favours 'cheating' in mutualisms is hotly debated. Gano-Cohen et al. (2019a) report a negative correlation between fitness and mutualist quality in rhizobia, suggesting that rhizobia evolve to cheat. However, reanalysis of their data shows that the correlation is an artefact of unequal sampling across populations.


Assuntos
Fabaceae , Rhizobium , Seleção Genética , Simbiose
2.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-31932537

RESUMO

Vigna is a genus of legumes cultivated in specific areas of tropical countries. Species in this genus are important crops worldwide. Vigna species are of great agronomic interest in Venezuela because Vigna beans are an excellent alternative to other legumes. However, this type of crop has some cultivation issues due to sensitivity to acidic soils, high temperatures, and salinity stress, which are common in Venezuela. Vigna species establish symbioses mainly with Bradyrhizobium and Ensifer, and Vigna-rhizobia interactions have been examined in Asia, Africa, and America. However, the identities of the rhizobia associated with V. radiata and V. unguiculata in Venezuela remain unknown. In the present study, we isolated Venezuelan symbiotic rhizobia associated with Vigna species from soils with contrasting agroecosystems or from fields in Venezuela. Several types of soils were used for bacterial isolation and nodules were sampled from environments characterized by abiotic stressors, such as high temperatures, high concentrations of NaCl, and acidic or alkaline pH. Venezuelan Vigna-rhizobia were mainly fast-growing. Sequencing of several housekeeping genes showed that in contrast to other continents, Venezuelan Vigna species were nodulated by rhizobia genus including Burkholderia, containing bacteria from several new phylogenetic lineages within the genus Bradyrhizobium. Some Rhizobium and Bradyrhizobium isolates were tolerant of high salinity and Al toxicity. The stress tolerance of strains was dependent on the type of rhizobia, soil origin, and cultivation history. An isolate classified as R. phaseoli showed the highest plant biomass, nitrogen fixation, and excellent abiotic stress response, suggesting a novel promising inoculant for Vigna cultivation in Venezuela.


Assuntos
Filogenia , Proteobactérias/classificação , Proteobactérias/fisiologia , Microbiologia do Solo , Simbiose , Vigna/microbiologia , DNA Bacteriano/genética , Genes Bacterianos/genética , Fixação de Nitrogênio/genética , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética , Nódulos Radiculares de Plantas/microbiologia , Análise de Sequência de DNA , Solo/química , Estresse Fisiológico , Venezuela , Vigna/crescimento & desenvolvimento
3.
Insect Sci ; 27(2): 256-265, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30047567

RESUMO

We tested the recent hypothesis that the "fly factor" phenomenon (food currently or previously fed on by flies attracts more flies than the same type of food kept inaccessible to flies) is mediated by bacterial symbionts deposited with feces or regurgitated by feeding flies. We allowed laboratory-reared black blow flies, Phormia regina (Meigen), to feed and defecate on bacterial Luria-Bertani medium solidified with agar, and isolated seven morphologically distinct bacterial colonies. We identified these using matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 16S rRNA gene. In two-choice laboratory experiments, traps baited with cultures of Proteus mirabilis Hauser, Morganella morganii subsp. sibonii Jensen, or Serratia marcescens Bizio, captured significantly more flies than corresponding control jars baited with tryptic soy agar only. A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate (M. m. sibonii). In a field experiment, traps baited with agar cultures of P. mirabilis and M. m. sibonii in combination captured significantly more flies than traps baited with either bacterial isolate alone or the agar control. As evident by gas chromatography-mass spectrometry, the odor profiles of bacterial isolates differ, which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits. As "generalist bacteria," P. mirabilis and M. m. sibonii growing on animal protein (beef liver) or plant protein (tofu) are similarly effective in attracting flies. Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.


Assuntos
Dípteros/microbiologia , Animais , Comportamento Apetitivo , Comportamento Alimentar , Feminino , Masculino , Odorantes/análise , Simbiose
4.
Bull Entomol Res ; 110(1): 22-33, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31190648

RESUMO

Plant-sucking stinkbugs are especially associated with mutualistic gut bacterial symbionts. Here, we explored the symbiotic relationship of a pistachio stinkbug, Acrosternum heegeri Fieber by histological, fluorescence in situ hybridization (FISH), real-time PCR and molecular phylogenetic techniques. Furthermore, the effects of the symbiont on the resting/wandering behaviors of the newborn nymphs, pre-adult survival rates, and stage compositions were investigated. Transmission electron microscopy and real-time PCR analyses showed that a rod-shaped gammaproteobacterium was persistently located within the posterior midgut crypts. Molecular phylogenetic and FISH techniques strongly suggested that this symbiont should be placed in the genus Pantoea of the Enterobacteriales. Scanning electron microscopy confirmed the presence of the bacterial cells on the egg surface which the surface sterilization of the eggs resulted in the successful removal of the symbiont from the eggs. Symbiotic and aposymbiotic A. heegeri showed no significant differences in the wandering behaviors of the first nymphal stages, while the symbiont-free insects suffered retarded growth and lower survivability. Together, the results highlight the habitat and acquisition features of Pantoea symbiont and its contribution in A. heegeri biology that might help us for better pest management in the future.


Assuntos
Gammaproteobacteria/isolamento & purificação , Heterópteros/microbiologia , Animais , Feminino , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/ultraestrutura , Heterópteros/ultraestrutura , Ovário/microbiologia , Óvulo/microbiologia , Simbiose
5.
Arch Virol ; 165(1): 127-135, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31741097

RESUMO

In clinical virome research, whole-genome/transcriptome amplification is required when starting material is limited. An improved method, named "template-dependent multiple displacement amplification" (tdMDA), has recently been developed in our lab (Wang et al. in BioTechniques 63:21-25. https://doi.org/10.2144/000114566, 2017). In combination with Illumina sequencing and bioinformatics pipelines, its application in virome sequencing was explored using a serum sample from a patient with chronic hepatitis C virus (HCV) infection. In comparison to an amplification-free procedure, virome sequencing via tdMDA showed a 9.47-fold enrichment for HCV-mapped reads and, accordingly, an increase in HCV genome coverage from 28.5% to 70.1%. Eight serum samples from acute patients liver failure (ALF) with or without known etiology were then used for virome sequencing with an average depth at 94,913x. Both similarity-based (mapping, NCBI BLASTn, BLASTp, and profile hidden Markov model analysis) and similarity-independent methods (machine-learning algorithms) identified viruses from multiple families, including Herpesviridae, Picornaviridae, Myoviridae, and Anelloviridae. However, their commensal nature and cross-detection ruled out an etiological interpretation. Together with a lack of detection of novel viruses in a comprehensive analysis at a resolution of single reads, these data indicate that viral agents might be rare in ALF cases with indeterminate etiology.


Assuntos
Biologia Computacional/métodos , Hepatite C Crônica/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Falência Hepática Aguda/virologia , Soro/virologia , Anelloviridae/isolamento & purificação , Anelloviridae/fisiologia , Perfilação da Expressão Gênica/métodos , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/sangue , Herpesviridae/isolamento & purificação , Herpesviridae/fisiologia , Humanos , Falência Hepática Aguda/sangue , Myoviridae/isolamento & purificação , Myoviridae/fisiologia , Picornaviridae/isolamento & purificação , Picornaviridae/fisiologia , Especificidade da Espécie , Simbiose , Sequenciamento Completo do Genoma/métodos
6.
Arch Virol ; 165(1): 11-20, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31620899

RESUMO

Southern tomato virus (STV) is often found infecting healthy tomato plants (Solanum lycopersicum). In this study, we compared STV-free and STV-infected plants of cultivar M82 to determine the effect of STV infection on the host plant. STV-free plants exhibited a short and bushy phenotype, whereas STV-infected plants were taller. STV-infected plants produced more fruit than STV-free plants, and the germination rate of seeds from STV-infected plants was higher than that of seeds from STV-free plants. This phenotypic difference was also observed in progeny plants (siblings) derived from a single STV-infected plant in which the transmission rate of STV to progeny plants via the seeds was approximately 86%. These results suggest that the interaction between STV and host plants is mutualistic. Transcriptome analysis revealed that STV infection affects gene expression in the host plant and results in downregulation of genes involved in ethylene biosynthesis and signaling. STV-infected tomato plants might thus be artificially selected due to their superior traits as a crop.


Assuntos
Perfilação da Expressão Gênica/métodos , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Plantas/genética , Vírus de Plantas/fisiologia , Infecções Assintomáticas , Etilenos/biossíntese , Frutas/crescimento & desenvolvimento , Frutas/virologia , Regulação da Expressão Gênica de Plantas , Germinação , Lycopersicon esculentum/genética , Lycopersicon esculentum/virologia , Fenótipo , Transdução de Sinais , Simbiose
7.
Arch Microbiol ; 202(1): 1-16, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31552478

RESUMO

The acerbic elevation of toxic metal ions in arable lands, enhance the risk of their accumulation and biomagnification in crops as well as in humans. Phytoremediation is an eco-friendly approach to clear metal-contaminated lands by making use of metal accumulation potential of plants; which are referred to as hyperaccumulators. This phytoremediation potential can be enhanced with the symbiotic association between the root of hyperaccumulators and arbuscular mycorrhizae. Modification of root morphology, enhancement of antioxidants biosynthesis, and the increase in shoot biomass are the changes observed in plants as a result of indirect influence of arbuscular mycorrhizae. Direct influence of arbuscular mycorrhizae on enhancing metal tolerance of plants includes immobilization strategies, adsorption of metals on to the hyphal wall and glomalin exudation. Furthermore, we have discussed arbuscular mycorrhizal induced increment in the metal tolerance potential of plants through the alteration in various metabolic processes with special emphasis to the phenylpropanoid pathway.


Assuntos
Biodegradação Ambiental , Metais/toxicidade , Micorrizas/metabolismo , Raízes de Plantas/microbiologia , Plantas/efeitos dos fármacos , Plantas/microbiologia , Simbiose/fisiologia , Biomassa , Poluentes do Solo/toxicidade
8.
Exp Parasitol ; 208: 107802, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31730782

RESUMO

In insects, diet plays an important role in growth and development. Insects can vary their diet composition based on their physiological needs. In this study we tested the influence of diet composition involving varying concentrations of macronutrients and zinc on the immune-tolerance following parasite and pathogen exposure in Spodoptera litura larvae. We also tested the insecticidal potential of Mesorhabditis belari, Enterobacter hormaechei and its secondary metabolites on Spodoptera litura larvae. The results shows macronutrient composition does not directly affect the larval tolerance to nematode infection. However, Zinc supplemented diet improved the immune tolerance. While larvae exposed to bacterial infection performed better on carbohydrate rich diet. Secondary metabolites from bacteria produced an immune response in dose dependent mortality. The study shows that the larvae maintained on different diet composition show varied immune tolerance which is based on the type of infection.


Assuntos
Enterobacter/fisiologia , Controle Biológico de Vetores , Rhabditoidea/fisiologia , Spodoptera/imunologia , Análise de Variância , Animais , Bioensaio , Carboidratos/administração & dosagem , Cromatografia Líquida de Alta Pressão , Dieta , Enterobacter/imunologia , Enterobacter/patogenicidade , Cromatografia Gasosa-Espectrometria de Massas , Tolerância Imunológica , Larva/imunologia , Dose Letal Mediana , Proteínas/administração & dosagem , Rhabditoidea/imunologia , Rhabditoidea/patogenicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Spodoptera/fisiologia , Simbiose , Virulência , Zinco/administração & dosagem
9.
Bull Entomol Res ; 110(1): 1-14, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31223102

RESUMO

Tephritidae is a large family that includes several fruit and vegetable pests. These organisms usually harbor a variegated bacterial community in their digestive systems. Symbiotic associations of bacteria and fruit flies have been well-studied in the genera Anastrepha, Bactrocera, Ceratitis, and Rhagoletis. Molecular and culture-based techniques indicate that many genera of the Enterobacteriaceae family, especially the genera of Klebsiella, Enterobacter, Pectobacterium, Citrobacter, Erwinia, and Providencia constitute the most prevalent populations in the gut of fruit flies. The function of symbiotic bacteria provides a promising strategy for the biological control of insect pests. Gut bacteria can be used for controlling fruit fly through many ways, including attracting as odors, enhancing the success of sterile insect technique, declining the pesticide resistance, mass rearing of parasitoids and so on. New technology and recent research improved our knowledge of the gut bacteria diversity and function, which increased their potential for pest management. In this review, we discussed the diversity of bacteria in the economically important fruit fly and the use of these bacteria for controlling fruit fly populations. All the information is important for strengthening the future research of new strategies developed for insect pest control by the understanding of symbiotic relationships and multitrophic interactions between host plant and insects.


Assuntos
Controle Biológico de Vetores , Tephritidae/microbiologia , Animais , Microbiota , Simbiose
10.
Ecol Lett ; 23(1): 2-15, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707763

RESUMO

Changing conditions may lead to sudden shifts in the state of ecosystems when critical thresholds are passed. Some well-studied drivers of such transitions lead to predictable outcomes such as a turbid lake or a degraded landscape. Many ecosystems are, however, complex systems of many interacting species. While detecting upcoming transitions in such systems is challenging, predicting what comes after a critical transition is terra incognita altogether. The problem is that complex ecosystems may shift to many different, alternative states. Whether an impending transition has minor, positive or catastrophic effects is thus unclear. Some systems may, however, behave more predictably than others. The dynamics of mutualistic communities can be expected to be relatively simple, because delayed negative feedbacks leading to oscillatory or other complex dynamics are weak. Here, we address the question of whether this relative simplicity allows us to foresee a community's future state. As a case study, we use a model of a bipartite mutualistic network and show that a network's post-transition state is indicated by the way in which a system recovers from minor disturbances. Similar results obtained with a unipartite model of facilitation suggest that our results are of relevance to a wide range of mutualistic systems.


Assuntos
Ecossistema , Modelos Biológicos , Previsões , Características de Residência , Simbiose
11.
Immunology ; 159(1): 26-38, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31777068

RESUMO

Mucosal tissues contain distinct microbial communities that differ drastically depending on the barrier site, and as such, mucosal immune responses have evolved to be tailored specifically for their location. Whether protective or regulatory immune responses against invading pathogens or the commensal microbiota occur is controlled by local mononuclear phagocytes (MNPs). Comprising macrophages and dendritic cells (DCs), the functions of these cells are highly dependent on the local environment. For example, the intestine contains the greatest bacterial load of any site in the body, and hence, intestinal MNPs are hyporesponsive to bacterial stimulation. This is thought to be one of the major mechanisms by which harmful immune responses directed against the trillions of harmless bacteria that line the gut lumen are avoided. Regulation of MNP function by the microbiota has been characterized in the most depth in the intestine but there are several mucosal sites that also contain their own microbiota. In this review, we present an overview of how MNP function is regulated by the microbiota at mucosal sites, highlighting recent novel pathways by which this occurs in the intestine, and new studies elucidating these interactions at mucosal sites that have been characterized in less depth, including the urogenital tract.


Assuntos
Imunidade nas Mucosas , Microbiota/imunologia , Sistema Fagocitário Mononuclear/imunologia , Membrana Mucosa/microbiologia , Simbiose/imunologia , Animais , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Tolerância Imunológica , Intestinos/imunologia , Intestinos/microbiologia , Pulmão/microbiologia , Modelos Animais , Boca/imunologia , Boca/microbiologia , Membrana Mucosa/imunologia , Sistema Urogenital/imunologia , Sistema Urogenital/microbiologia
12.
Insect Sci ; 27(1): 86-98, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29749703

RESUMO

Bacterial endosymbionts play important roles in ecological traits of aphids. In this study, we characterize the bacterial endosymbionts of A. gossypii collected in Karaj, Iran and their role in the performance of the aphid. Our results indicated that beside Buchnera aphidicola, A. gossypii, also harbors both Hamiltonella defensa and Arsenophonus sp. Quantitative PCR (qPCR) results revealed that the populations of the endosymbionts increased throughout nymphal development up to adult emergence; thereafter, populations of Buchnera and Arsenophonus were diminished while the density of H. defensa constantly increased. Buchnera reduction caused prolonged development and no progeny production. Furthermore, secondary symbiont reduction led to reduction of the total life span and intrinsic rate of natural increase as well as appearance of the deformed dead offspring in comparison with the control insects. Reduction of the secondary symbionts did not affect parasitism rate of the aphid by the parasitic wasp Aphidius matricariae. Together these findings showed that H. defensa and Arsenophonus contributed to the fitness of A. gossypii by enhancing its performance, but not through parasitoid resistance.


Assuntos
Afídeos/microbiologia , Afídeos/fisiologia , Buchnera/fisiologia , Enterobacteriaceae/fisiologia , Simbiose , Animais , Afídeos/crescimento & desenvolvimento , Irã (Geográfico) , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Reprodução , Especificidade da Espécie
13.
Insect Sci ; 27(1): 69-85, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29797656

RESUMO

Bacterial endosymbionts have enabled aphids to adapt to a range of stressors, but their effects in many aphid species remain to be established. The bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus), is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria, although the resulting aphid phenotype has not been described. This study presents the first report of R. padi infection with the facultative bacterial endosymbiont Hamiltonella defensa. Individuals of R. padi were sampled from populations in Eastern Scotland, UK, and shown to represent seven R. padi genotypes based on the size of polymorphic microsatellite markers; two of these genotypes harbored H. defensa. In parasitism assays, survival of H. defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani (Viereck) was 5 fold higher than for uninfected nymphs. Aphid genotype was a major determinant of aphid performance on two Hordeum species, a modern cultivar of barley H. vulgare and a wild relative H. spontaneum, although aphids infected with H. defensa showed 16% lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals. These findings suggest that deploying resistance traits in barley will favor the fittest R. padi genotypes, but symbiont-infected individuals will be favored when parasitoids are abundant, although these aphids will not achieve optimal performance on a poor quality host plant.


Assuntos
Afídeos/microbiologia , Enterobacteriaceae/fisiologia , Simbiose , Animais , Afídeos/genética , Afídeos/crescimento & desenvolvimento , Genótipo , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Escócia
14.
mSphere ; 4(6)2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801843

RESUMO

The work presented by Audry et al. (M. Audry, C. Robbe-Masselot, J.-P. Barnier, B. Gachet, et al., mSphere 4:e00494-19, 2019, https://doi.org/10.1128/mSphere.00494-19) gives new insight into the interactions of Neisseria meningitidis and the human nasopharynx. Using an air interface tissue culture model of a polarized, mucus-secreting epithelium, Audry et al. demonstrate that N. meningitidis bacteria do not commonly invade epithelial cells. Rather, they are trapped in the mucus layer, where they are protected from dessication. In this model, meningicocci fail to elicit a pro-inflammatory immune response and show growth effects in response to another nasopharyngeal colonizer, Streptococcus mitis These findings prompt new questions about pathobiont behaviors, the role of mucus in bacterium-host interactions, and modeling human infection.


Assuntos
Neisseria meningitidis , Células Epiteliais , Humanos , Inflamação , Membrana Mucosa , Muco , Simbiose
15.
BMC Evol Biol ; 19(1): 224, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818253

RESUMO

BACKGROUND: Eukaryotes acquired the trait of oxygenic photosynthesis through endosymbiosis of the cyanobacterial progenitor of plastid organelles. Despite recent advances in the phylogenomics of Cyanobacteria, the phylogenetic root of plastids remains controversial. Although a single origin of plastids by endosymbiosis is broadly supported, recent phylogenomic studies are contradictory on whether plastids branch early or late within Cyanobacteria. One underlying cause may be poor fit of evolutionary models to complex phylogenomic data. RESULTS: Using Posterior Predictive Analysis, we show that recently applied evolutionary models poorly fit three phylogenomic datasets curated from cyanobacteria and plastid genomes because of heterogeneities in both substitution processes across sites and of compositions across lineages. To circumvent these sources of bias, we developed CYANO-MLP, a machine learning algorithm that consistently and accurately phylogenetically classifies ("phyloclassifies") cyanobacterial genomes to their clade of origin based on bioinformatically predicted function-informative features in tRNA gene complements. Classification of cyanobacterial genomes with CYANO-MLP is accurate and robust to deletion of clades, unbalanced sampling, and compositional heterogeneity in input tRNA data. CYANO-MLP consistently classifies plastid genomes into a late-branching cyanobacterial sub-clade containing single-cell, starch-producing, nitrogen-fixing ecotypes, consistent with metabolic and gene transfer data. CONCLUSIONS: Phylogenomic data of cyanobacteria and plastids exhibit both site-process heterogeneities and compositional heterogeneities across lineages. These aspects of the data require careful modeling to avoid bias in phylogenomic estimation. Furthermore, we show that amino acid recoding strategies may be insufficient to mitigate bias from compositional heterogeneities. However, the combination of our novel tRNA-specific strategy with machine learning in CYANO-MLP appears robust to these sources of bias with high accuracy in phyloclassification of cyanobacterial genomes. CYANO-MLP consistently classifies plastids as late-branching Cyanobacteria, consistent with independent evidence from signature-based approaches and some previous phylogenetic studies.


Assuntos
Cianobactérias/genética , Eucariotos/citologia , Eucariotos/genética , Plastídeos/genética , Evolução Biológica , Modelos Biológicos , Fotossíntese , Filogenia , RNA de Transferência , Simbiose
16.
Ying Yong Sheng Tai Xue Bao ; 30(11): 3971-3979, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31833711

RESUMO

Arbuscular mycorrhizal fungi (AMF) are ancient and ubiquitous soil microorganisms, which can form mutually beneficial association with most terrestrial plants. Within the symbiotic relationship, AMF helps their host plants to absorb nutrients such as nitrogen and phosphorus while obtains carbon from the hosts. AMF plays an important role in agricultural ecosystem, including promoting plant growth, improving crop quality, increasing plant stress resistance, stabilizing soil structure, keeping ecological balance, and maintaining a sustainable agricultural development. We summarized the research advances of AMF in terrestrial agro-ecosystem in recent years, by focusing on AMF species diversity, spatial and temporal distribution, and influence factors of AMF biodiversity in terrestrial agro-ecosystem of China. Further research works were also prospected.


Assuntos
Micorrizas , Biodiversidade , China , Ecossistema , Fungos , Raízes de Plantas , Microbiologia do Solo , Simbiose
17.
Oecologia ; 191(4): 983-993, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31679040

RESUMO

Understanding the differences in fine-root traits among different species is essential to gain a detailed understanding of resource conservation and acquisition strategies of plants. We aimed to explore whether certain root traits are consistent among subsets of species and characterize species together into meaningful community groups. We selected 11 woody species from different microbial symbiotic groups (ectomycorrhiza, arbuscular mycorrhiza, and rhizobia) and phylogenetic groups (broad-leaved angiosperms and coniferous gymnosperms) from the cool temperate forests of Nagano, Japan. We measured root architectural (branching intensity), morphological (root tissue density and specific root length), chemical (N and K concentrations), and anatomical (total stele and total cortex) traits. Significant differences were observed in all root traits, although many species did not differ from one another. Branching intensity was found to be the greatest variation in the measured root traits across the 11 woody species. The results of a principal component analysis of root traits showed a distinct separation between angiosperms and gymnosperms. We identified clusters of species based on their multidimensional root traits that were consistent with the different phylogenetic microbial association groups. Gymnosperm roots may be more resource conservative, while angiosperm roots may be more acquisitive for water and nutrients. We consider that the advances in root traits combination will make a breakthrough in our ability to differentiate the community groups rather than individual root trait.


Assuntos
Raízes de Plantas , Simbiose , Florestas , Japão , Filogenia
18.
J Chem Ecol ; 45(10): 879-887, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31686336

RESUMO

Many species of morning glories (Convolvulaceae) form symbioses with seed-transmitted Periglandula fungal endosymbionts, which produce ergot alkaloids and may contribute to defensive mutualism. Allocation of seed-borne ergot alkaloids to various tissues of several Ipomoea species has been demonstrated, including roots of I. tricolor. The goal of this study was to determine if infection of I. tricolor by the Periglandula sp. endosymbiont affects Southern root-knot nematode (Meloidogyne incognita) gall formation and host plant biomass. We hypothesized that I. tricolor plants infected by Periglandula (E+) would develop fewer nematode-induced galls compared to non-symbiotic plants (E-). E+ or E- status of plant lines was confirmed by testing methanol extracts from individual seeds for endosymbiont-produced ergot alkaloids. To test the effects of Periglandula on nematode colonization, E+ and E- I. tricolor seedlings were grown in soil infested with high densities of M. incognita nematodes (N+) or no nematodes (N-) for four weeks in the greenhouse before harvesting. After harvest, nematode colonization of roots was visualized microscopically, and total gall number and plant biomass were quantified. Four ergot alkaloids were detected in roots of E+ plants, but no alkaloids were found in E- plants. Gall formation was reduced by 50% in E+ plants compared to E- plants, independent of root biomass. Both N+ plants and E+ plants had significantly reduced biomass compared to N- and E- plants, respectively. These results demonstrate Periglandula's defensive role against biotic enemies, albeit with a potential trade-off with host plant growth.


Assuntos
Alcaloides de Claviceps/química , Hypocreales/metabolismo , Ipomoea/parasitologia , Tylenchoidea/fisiologia , Animais , Biomassa , Cromatografia Líquida de Alta Pressão , Alcaloides de Claviceps/análise , Ipomoea/química , Ipomoea/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/parasitologia , Tumores de Planta/parasitologia , Sementes/química , Sementes/metabolismo , Solo/parasitologia , Espectrometria de Massas por Ionização por Electrospray , Simbiose
19.
Parasitol Res ; 118(12): 3565-3570, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31701295

RESUMO

The flagellated protozoon Trichomonas vaginalis, responsible for trichomoniasis, can establish a symbiotic relationship with the bacterium Mycoplasma hominis and can harbor double-stranded RNA Trichomonasvirus (TVV). In this study, we investigated by real-time PCR the prevalence of the four TVVs and of M. hominis among 48 T. vaginalis strains isolated in Italy, and we evaluated a possible association with metronidazole resistance. Fifty percent of the analyzed trichomonad strains tested positive for at least one TVV T. vaginalis, with TVV2 being the most prevalent, followed by TVV1 and TVV3. Two T. vaginalis strains were infected by TVV4, detected in Europe for the first time. Interestingly, we found more than one TVV species in 75% of positive trichomonad strains. M. hominis was present in 81.25% of T. vaginalis isolates tested, and no statistically significant association was observed with the infection by any TVV. Metronidazole sensitivity of T. vaginalis isolates was evaluated in vitro, and no correlation was observed between minimal lethal concentration and the presence of TVVs. This is the first report on TVV infection of T. vaginalis in Italy. Even if no association of TVV positive isolates with the presence of the symbiont M. hominis or with metronidazole resistance was observed, further studies are needed to shed light on the effective role of infecting microorganisms on the pathophysiology of T. vaginalis.


Assuntos
Mycoplasma hominis/isolamento & purificação , Vírus de RNA/isolamento & purificação , Trichomonas vaginalis/microbiologia , Trichomonas vaginalis/virologia , Antiprotozoários/farmacologia , Resistência a Medicamentos , Humanos , Itália , Metronidazol/farmacologia , Mycoplasma hominis/classificação , Mycoplasma hominis/genética , Mycoplasma hominis/fisiologia , Prevalência , Vírus de RNA/classificação , Vírus de RNA/genética , Vírus de RNA/fisiologia , RNA de Cadeia Dupla/genética , RNA Viral/genética , Simbiose , Tricomoníase/parasitologia , Trichomonas vaginalis/efeitos dos fármacos , Trichomonas vaginalis/fisiologia
20.
Zootaxa ; 4612(1): zootaxa.4612.1.13, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31717088

RESUMO

Despite the ubiquitous nature of symbiosis in palaemonid shrimps (Caridea: Palaemonidae) which live in or on varied invertebrate hosts, such as echinoderms, sponges, ascidians, hard and soft corals, etc., very few taxa have been recorded living in burrows constructed by other animals. This is in sharp contrast to the rich burrow-dwelling diversity in the Alpheidae, in which numerous genera associate with a great variety of burrowing animals, including stomatopods (Hayashi 2002; Duris Anker 2014), echiurans (Anker et al. 2005, 2015), other alpheid shrimps (e.g. De Grave 2004; Anker Marin 2006), and especially numerous ghost and mud shrimps (e.g. Anker, 2011; Anker Lazarus 2015).


Assuntos
Palaemonidae , Distribuição Animal , Estruturas Animais , Animais , Equinodermos , Simbiose
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