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1.
IEEE Trans Pattern Anal Mach Intell ; 45(7): 9122-9134, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37022222

RESUMO

We present a novel approach for disentangling the content of a text image from all aspects of its appearance. The appearance representation we derive can then be applied to new content, for one-shot transfer of the source style to new content. We learn this disentanglement in a self-supervised manner. Our method processes entire word boxes, without requiring segmentation of text from background, per-character processing, or making assumptions on string lengths. We show results in different text domains which were previously handled by specialized methods, e.g., scene text, handwritten text. To these ends, we make a number of technical contributions: (1) We disentangle the style and content of a textual image into a non-parametric, fixed-dimensional vector. (2) We propose a novel approach inspired by StyleGAN but conditioned over the example style at different resolution and content. (3) We present novel self-supervised training criteria which preserve both source style and target content using a pre-trained font classifier and text recognizer. Finally, (4) we also introduce Imgur5K, a new challenging dataset for handwritten word images. We offer numerous qualitative photo-realistic results of our method. We further show that our method surpasses previous work in quantitative tests on scene text and handwriting datasets, as well as in a user study.

2.
J Hazard Mater ; 453: 131399, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37062095

RESUMO

Research into plastic-degrading bacteria and fungi is important for understanding how microorganisms can be used to address the problem of plastic pollution and for developing new approaches to sustainable waste management and bioplastic production. In the present study, we isolated 55 bacterial and 184 fungal strains degrading polycaprolactone (PCL) in plastic waste samples from Dafeng coastal salt marshes, Jiangsu, China. Of these, Jonesia and Streptomyces bacteria also showed potential to degrade other types of petroleum-based polymers. The metabarcoding results proved the existence of plastisphere as a distinct ecological niche regardless of the plastic types where 27 bacterial and 29 fungal amplicon sequence variants (ASVs) were found to be significantly (p < 0.05) enriched, including some belonging to Alternaria (Ascomycota, Fungi) and Pseudomonas (Gammaproteobacteria, Bacteria) that were also mined out by the method of cultivation. Further assembly analyses demonstrated the importance of deterministic processes especially the environmental filtering effect of carbon content and pH on bacteria as well as the carbon and cation content on fungi in shaping the plastisphere communities in this ecosystem. Thus, the unique microbiome of the plastisphere in the terrestrial-marine ecotone is enriched with microorganisms that are potentially capable of utilizing petroleum-based polymers, making it a valuable resource for screening plastic biodegraders.


Assuntos
Ascomicetos , Microbiota , Petróleo , Polímeros , Plásticos , Bactérias/genética , Biodegradação Ambiental
3.
J Agric Food Chem ; 70(37): 11769-11781, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36084284

RESUMO

Filamentous fungi produce a great variety of bioactive secondary metabolites essential for their biotic interactions. Here, we characterized an exceptional Trichoderma mutant overproducing harzianic acids (HAs) with exclusively highly antifungal activity against numerous fungi from different ecological groups. Interestingly, two transcription factors (TFs) were identified in this HA biosynthetic gene cluster (hac BGC), with HacI regulating the biosynthetic genes and HacF being likely responsible for the product transportation essential for the self-detoxification of the fungus from the produced HAs. Evolutionary analysis suggested that the sparse distribution of hac BGC in many environmental opportunistic fungi including several species from Trichoderma, Penicillium, and Aspergillus could result from lateral gene transfers and pervasive gene losses in different lineages of Pezizomycotina. Taken together, we propose that the production of HAs by fungi is to inhibit the growth of the surrounding partners to secure an exclusive position in a competitive community.


Assuntos
Ascomicetos , Vias Biossintéticas , Antifúngicos/metabolismo , Ascomicetos/metabolismo , Vias Biossintéticas/genética , Família Multigênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Microbiol Spectr ; 10(4): e0226821, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35946960

RESUMO

The Pythium (Peronosporales, Oomycota) genus includes devastating plant pathogens that cause widespread diseases and severe crop losses. Here, we have uncovered a far greater arsenal of virulence factor-related genes in the necrotrophic Pythium myriotylum than in other Pythium plant pathogens. The genome of a plant-virulent P. myriotylum strain (~70 Mb and 19,878 genes) isolated from a diseased rhizome of ginger (Zingiber officinale) encodes the largest repertoire of putative effectors, proteases, and plant cell wall-degrading enzymes (PCWDEs) among the studied species. P. myriotylum has twice as many predicted secreted proteins than any other Pythium plant pathogen. Arrays of tandem duplications appear to be a key factor of the enrichment of the virulence factor-related genes in P. myriotylum. The transcriptomic analysis performed on two P. myriotylum isolates infecting ginger leaves showed that proteases were a major part of the upregulated genes along with PCWDEs, Nep1-like proteins (NLPs), and elicitin-like proteins. A subset of P. myriotylum NLPs were analyzed and found to have necrosis-inducing ability from agroinfiltration of tobacco (Nicotiana benthamiana) leaves. One of the heterologously produced infection-upregulated putative cutinases found in a tandem array showed esterase activity with preferences for longer-chain-length substrates and neutral to alkaline pH levels. Our results allow the development of science-based targets for the management of P. myriotylum-caused disease, as insights from the genome and transcriptome show that gene expansion of virulence factor-related genes play a bigger role in the plant parasitism of Pythium spp. than previously thought. IMPORTANCE Pythium species are oomycetes, an evolutionarily distinct group of filamentous fungus-like stramenopiles. The Pythium genus includes several pathogens of important crop species, e.g., the spice ginger. Analysis of our genome from the plant pathogen Pythium myriotylum uncovered a far larger arsenal of virulence factor-related genes than found in other Pythium plant pathogens, and these genes contribute to the infection of the plant host. The increase in the number of virulence factor-related genes appears to have occurred through the mechanism of tandem gene duplication events. Genes from particular virulence factor-related categories that were increased in number and switched on during infection of ginger leaves had their activities tested. These genes have toxic activities toward plant cells or activities to hydrolyze polymeric components of the plant. The research suggests targets to better manage diseases caused by P. myriotylum and prompts renewed attention to the genomics of Pythium plant pathogens.


Assuntos
Pythium , Zingiber officinale , Peptídeo Hidrolases , Doenças das Plantas , Plantas , Pythium/genética , Virulência/genética , Fatores de Virulência/genética
5.
Environ Microbiol ; 23(10): 5784-5801, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33788384

RESUMO

Hypocrealean Trichoderma are the most extensively studied facultative mycoparasites against phytopathogenic fungi. Aerial hyphae of Trichoderma guizhouense can rapidly proliferate over Fusarium oxysporum hyphae, cause sporadic cell death and arrest the growth of the host. The results of the present study demonstrated that a unique short-chain dehydrogenase/reductase (SDR), designated as TgSDR1, was expressed at a high level in T. guizhouense challenged by the hosts. Similar to other SDRs family members, the TgSDR1 protein contains a cofactor-binding motif and a catalytic site. The subcellular localization assay revealed that the TgSDR1::GFP fusion protein translocated to lipid droplets in mycelia and conidia. The data obtained using reverse genetic approach indicated that TgSDR1 is associated with antifungal ability, plays an important role in providing reducing equivalents in the form of NADPH and regulates the amino sugar and nucleotide sugar metabolism in T. guizhouense upon encountering a host. Moreover, the TgSDR1 deletion mutant was defective in conidiation. Thus, TgSDR1 functions as a key metabolic enzyme in T. guizhouense to regulate mycotrophic interactions, defence against other fungi, such as F. oxysporum, and conidiation.


Assuntos
Fusarium , Hypocreales , Redutases-Desidrogenases de Cadeia Curta , Trichoderma , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/metabolismo , Hifas/metabolismo , Hypocreales/metabolismo , Redutases-Desidrogenases de Cadeia Curta/metabolismo , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo , Trichoderma/metabolismo
6.
Environ Microbiol ; 23(10): 5750-5768, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33538393

RESUMO

The secretomes of filamentous fungi contain a diversity of small secreted cysteine-rich proteins (SSCPs) that have a variety of properties ranging from toxicity to surface activity. Some SSCPs are recognized by other organisms as indicators of fungal presence, but their function in fungi is not fully understood. We detected a new family of fungal surface-active SSCPs (saSSCPs), here named hyphosphere proteins (HFSs). An evolutionary analysis of the HFSs in Pezizomycotina revealed a unique pattern of eight single cysteine residues (C-CXXXC-C-C-C-C-C) and a long evolutionary history of multiple gene duplications and ancient interfungal lateral gene transfers, suggesting their functional significance for fungi with different lifestyles. Interestingly, recombinantly produced saSSCPs from three families (HFSs, hydrophobins and cerato-platanins) showed convergent surface-modulating activity on glass and on poly(ethylene-terephthalate), transforming their surfaces to a moderately hydrophilic state, which significantly favoured subsequent hyphal attachment. The addition of purified saSSCPs to the tomato rhizosphere had mixed effects on hyphal attachment to roots, while all tested saSSCPs had an adverse effect on plant growth in vitro. We propose that the exceptionally high diversity of saSSCPs in Trichoderma and other fungi evolved to efficiently condition various surfaces in the hyphosphere to a fungal-beneficial state.


Assuntos
Proteínas Fúngicas , Trichoderma , Cisteína/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Propriedades de Superfície , Trichoderma/metabolismo
7.
Environ Microbiol ; 22(11): 4808-4824, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32985773

RESUMO

Filamentous fungi are known as producers of a large array of diverse secondary metabolites (SMs) that aid in securing their environmental niche. Here, we demonstrated that the SMs have an additional role in fungal defence against other fungi: Trichoderma guizhouense, a mycoparasite, is able to antagonize Fusarium oxysporum f. sp. cubense race 4 (Foc4) by forming aerial hyphae that kill the host with hydrogen peroxide. At the same time, a gene cluster comprising two polyketide synthases is strongly expressed. Using functional genetics, we characterized this cluster and identified its products as azaphilones (termed as trigazaphilones). The trigazaphilones were found lacking of antifungal toxicity but exhibited high radical scavenging activities. The antioxidant property of trigazaphilones was in vivo functional under various tested conditions of oxidative stress. Thus, we conclude that the biosynthesis of trigazaphilones serves as a complementary antioxidant mechanism and defends T. guizhouense against the hydrogen peroxide that it produces to combat other fungi like Foc4.


Assuntos
Antioxidantes/metabolismo , Benzopiranos/metabolismo , Hypocreales/metabolismo , Estresse Oxidativo , Pigmentos Biológicos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/fisiologia , Peróxido de Hidrogênio/metabolismo , Hifas/metabolismo , Hypocreales/genética , Família Multigênica , Trichoderma/classificação , Trichoderma/genética , Trichoderma/metabolismo
8.
AMB Express ; 9(1): 179, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31707479

RESUMO

Survival of inoculated fungal strains in a new environment plays a critical role in functional performance, but few studies have focused on strain-specific quantitative PCR (qPCR) methods for monitoring beneficial fungi. In this study, the Trichoderma guizhouense strain NJAU 4742 (transformed with the gfp gene and named gfp-NJAU 4742), which exhibits a growth-promoting effect by means of phytohormone production and pathogen antagonism, was selected as a model to design strain-specific primer pairs using two steps of genomic sequence comparison to detect its abundance in soil. After a second comparison with the closely related species T. harzianum CBS 226-95 to further differentiate the strain-specific fragments that had shown no homology to any sequence deposited in the databases used in the first comparison, ten primer pairs were designed from the whole genome. Meanwhile, 3 primer pairs, P11, P12 and P13, were also designed from the inserted fragment containing the gfp gene. After verification testing with three types of field soils, primer pairs P6, P7 and P8 were further selected by comparison with P11, P12 and P13. A practical test using a pot experiment showed that stable colonization of gfp-NJAU 4742 in pepper rhizosphere soil could be detected using primer pairs P6 and P7, showing no significant difference from the results of primers P11 and P12. Hence, the strategy described here for designing fungal-strain-specific primers may theoretically be used for any other fungi for which the whole genome sequence is available in a database, and the qPCR methodology developed can also be used to further monitor the population dynamics of different strains based on the designed primers.

9.
Environ Microbiol ; 21(8): 2644-2658, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30815928

RESUMO

When resources are limited, the hypocrealean fungus Trichoderma guizhouense can overgrow another hypocrealean fungus Fusarium oxysporum, cause sporadic cell death and arrest growth. A transcriptomic analysis of this interaction shows that T. guizhouense undergoes a succession of metabolic stresses while F. oxysporum responded relatively neutrally but used the constitutive expression of several toxin-encoding genes as a protective strategy. Because of these toxins, T. guizhouense cannot approach it is potential host on the substrate surface and attacks F. oxysporum from above. The success of T. guizhouense is secured by the excessive production of hydrogen peroxide (H2 O2 ), which is stored in microscopic bag-like guttation droplets hanging on the contacting hyphae. The deletion of NADPH oxidase nox1 and its regulator, nor1 in T. guizhouense led to a substantial decrease in H2 O2 formation with concomitant loss of antagonistic activity. We envision the role of NOX proteins in the antagonism of T. guizhouense as an example of metabolic exaptation evolved in this fungus because the primary function of these ancient proteins was probably not linked to interfungal relationships. In support of this, F. oxysporum showed almost no transcriptional response to T. guizhouense Δnox1 strain indicating the role of NOX/H2 O2 in signalling and fungal communication.


Assuntos
Fusarium/metabolismo , Peróxido de Hidrogênio/metabolismo , NADPH Oxidases/metabolismo , Trichoderma/metabolismo , Evolução Biológica , Fusarium/crescimento & desenvolvimento , Hifas/crescimento & desenvolvimento , NADPH Oxidases/genética , Oxirredução , Trichoderma/enzimologia , Trichoderma/crescimento & desenvolvimento
10.
PLoS One ; 10(6): e0130081, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26110536

RESUMO

Trichoderma harzianum strain SQR-T037 is a biocontrol agent that has been shown to enhance the uptake of nutrients (macro- and microelements) by plants in fields. The objective of this study was to investigate the contribution of SQR-T037 to P and microelement (Fe, Mn, Cu and Zn) nutrition in tomato plants grown in soil and in hydroponic conditions. Inoculation with SQR-T037 significantly improved the biomass and nutrient uptake of tomato seedlings grown in a nutrient-limiting soil. So we investigated the capability of SQR-T037 to solubilise sparingly soluble minerals in vitro via four known mechanisms: acidification by organic acids, chelation by siderophores, redox by ferric reductase and hydrolysis by phytase. SQR-T037 was able to solubilise phytate, Fe2O3, CuO, and metallic Zn but not Ca3(PO4)2 or MnO2. Organic acids, including lactic acid, citric acid, tartaric acid and succinic acid, were detected by HPLC and LC/MS in two Trichoderma cultures. Additionally, we inoculated tomato seedlings with SQR-T037 using a hydroponic system with specific nutrient deficiencies (i.e., nutrient solutions deficient in P, Fe, Cu or Zn and supplemented with their corresponding solid minerals) to better study the effects of Trichoderma inoculation on plant growth and nutrition. Inoculated seedlings grown in Cu-deficient hydroponic conditions exhibited increases in dry plant biomass (92%) and Cu uptake (42%) relative to control plants. However, we did not observe a significant effect on seedling biomass in plants grown in the Fe- and Zn-deficient hydroponic conditions; by contrast, the biomass decreased by 82% in the P-deficient hydroponic condition. Thus, we demonstrated that Trichoderma SQR-T037 competed for P (phytate) and Zn with tomato seedlings by suppressing root development, releasing phytase and/or chelating minerals. The results of this study suggest that the induction of increased or suppressed plant growth occurs through the direct effect of T. harzianum on root development, in combination with indirect mechanisms, such as mineral solubilisation (including solubilisation via acidification, redox, chelation and hydrolysis).


Assuntos
Micronutrientes , Fosfatos , Desenvolvimento Vegetal/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Solanum lycopersicum/crescimento & desenvolvimento , Trichoderma , Microbiologia do Solo
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