Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.575
Filtrar
1.
Toxins (Basel) ; 15(1)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36668865

RESUMO

Pathogenic fungi in the genera Alternaria, Aspergillus, Botrytis, Fusarium, Geotrichum, Gloeosporium, Monilinia, Mucor, Penicillium, and Rhizopus are the most common cause of pre- and postharvest diseases of fruit, vegetable, root and grain commodities. Some species are also able to produce mycotoxins, secondary metabolites having toxic effects on human and non-human animals upon ingestion of contaminated food and feed. Synthetic fungicides still represent the most common tool to control these pathogens. However, long-term application of fungicides has led to unacceptable pollution and may favour the selection of fungicide-resistant mutants. Microbial biocontrol agents may reduce the incidence of toxigenic fungi through a wide array of mechanisms, including competition for the ecological niche, antibiosis, mycoparasitism, and the induction of resistance in the host plant tissues. In recent years, the emission of volatile organic compounds (VOCs) has been proposed as a key mechanism of biocontrol. Their bioactivity and the absence of residues make the use of microbial VOCs a sustainable and effective alternative to synthetic fungicides in the management of postharvest pathogens, particularly in airtight environments. In this review, we will focus on the possibility of applying yeast VOCs in the biocontrol of mycotoxigenic fungi affecting stored food and feed.


Assuntos
Armas de Fogo , Fungicidas Industriais , Micotoxinas , Perfumes , Compostos Orgânicos Voláteis , Animais , Micotoxinas/metabolismo , Saccharomyces cerevisiae/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Compostos Orgânicos Voláteis/metabolismo , Fungicidas Industriais/farmacologia , Fungos/metabolismo , Alternaria/metabolismo
2.
Toxins (Basel) ; 15(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36668870

RESUMO

Fusaric acid (FA) is one of the first secondary metabolites isolated from phytopathogenic fungi belonging to the genus Fusarium. This molecule exerts a toxic effect on plants, rhizobacteria, fungi and animals, and it plays a crucial role in both plant and animal pathogenesis. In plants, metal chelation by FA is considered one of the possible mechanisms of action. Here, we evaluated the effect of different nitrogen sources, iron content, extracellular pH and cellular signalling pathways on the production of FA siderophores by the pathogen Fusarium oxysporum (Fol). Our results show that the nitrogen source affects iron chelating activity and FA production. Moreover, alkaline pH and iron limitation boost FA production, while acidic pH and iron sufficiency repress it independent of the nitrogen source. FA production is also positively regulated by the cell wall integrity (CWI) mitogen-activated protein kinase (MAPK) pathway and inhibited by the iron homeostasis transcriptional regulator HapX. Collectively, this study demonstrates that factors promoting virulence (i.e., alkaline pH, low iron availability, poor nitrogen sources and CWI MAPK signalling) are also associated with increased FA production in Fol. The obtained new insights on FA biosynthesis regulation can be used to prevent both Fol infection potential and toxin contamination.


Assuntos
Fusarium , Animais , Fusarium/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Ácido Fusárico/farmacologia , Ácido Fusárico/metabolismo , Fungos/metabolismo , Parede Celular/metabolismo , Ferro/metabolismo , Concentração de Íons de Hidrogênio , Doenças das Plantas/microbiologia
3.
Toxins (Basel) ; 15(1)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36668881

RESUMO

Mycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of deleterious organisms in foodstuff. Ozone treatment (O3, 500 ppb for 30, 60 or 90 min) and high nitrogen concentration (N2, 99% for 21 consecutive days) were tested in the post-harvest management of four batches of Cicer arietinum grains to control the presence of mycotoxigenic fungi and their secondary metabolites, as well as pest (i.e., Callosobruchus maculatus) infestation. At the end of the treatment, O3 significantly decreased the incidence of Penicillium spp. (by an average of -50%, independently to the time of exposure) and reduced the patulin and aflatoxins content after 30 min (-85 and -100%, respectively). High N2 concentrations remarkably reduced mycotoxins contamination (by an average of -94%) and induced pest mortality (at 100% after 5 days of exposure). These results confirm the promising potential of O3 and N2 in post-harvest conservation strategies, leading to further investigations to evaluate the effects on the qualitative characteristics of grains.


Assuntos
Cicer , Micotoxinas , Patulina , Vigna , Gorgulhos , Humanos , Animais , Micotoxinas/análise , Fungos/metabolismo , Sementes/química , Patulina/análise , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise
4.
Int J Mol Sci ; 24(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36674833

RESUMO

Hispidin is a polyketide found in plants and fungi. In bioluminescent fungi, hispidin serves as a precursor of luciferin and is produced by hispidin synthases. Previous studies revealed that hispidin synthases differ in orthologous polyketide synthases from non-bioluminescent fungi by the absence of two domains with predicted ketoreductase and dehydratase activities. Here, we investigated the hypothesis that the loss of these domains in evolution led to the production of hispidin and the emergence of bioluminescence. We cloned three orthologous polyketide synthases from non-bioluminescent fungi, as well as their truncated variants, and assessed their ability to produce hispidin in a bioluminescence assay in yeast. Interestingly, expression of the full-length enzyme hsPKS resulted in dim luminescence, indicating that small amounts of hispidin are likely being produced as side products of the main reaction. Deletion of the ketoreductase and dehydratase domains resulted in no luminescence. Thus, domain truncation by itself does not appear to be a sufficient step for the emergence of efficient hispidin synthases from orthologous polyketide synthases. At the same time, the production of small amounts of hispidin or related compounds by full-length enzymes suggests that ancestral fungal species were well-positioned for the evolution of bioluminescence.


Assuntos
Policetídeo Sintases , Pironas , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Óxido Nítrico Sintase/metabolismo , Fungos/genética , Fungos/metabolismo , Hidroliases/metabolismo
5.
Molecules ; 28(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36677748

RESUMO

Invasive fungal infections represent a public health problem that worsens over the years with the increasing resistance to current antimycotic agents. Therefore, there is a compelling medical need of widening the antifungal drug repertoire, following different methods such as drug repositioning, identification and validation of new molecular targets and developing new inhibitors against these targets. In this work we developed a structure-based strategy for drug repositioning and new drug design, which can be applied to infectious fungi and other pathogens. Instead of applying the commonly accepted off-target criterion to discard fungal proteins with close homologues in humans, the core of our approach consists in identifying fungal proteins with active sites that are structurally similar, but preferably not identical to binding sites of proteins from the so-called "human pharmacolome". Using structural information from thousands of human protein target-inhibitor complexes, we identified dozens of proteins in fungal species of the genera Histoplasma, Candida, Cryptococcus, Aspergillus and Fusarium, which might be exploited for drug repositioning and, more importantly, also for the design of new fungus-specific inhibitors. As a case study, we present the in vitro experiments performed with a set of selected inhibitors of the human mitogen-activated protein kinases 1/2 (MEK1/2), several of which showed a marked cytotoxic activity in different fungal species.


Assuntos
Antifúngicos , Micoses , Humanos , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Candida/metabolismo , Proteínas Fúngicas/química , Domínio Catalítico , Fungos/metabolismo
6.
PLoS Biol ; 21(1): e3001945, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36656825

RESUMO

Studies focused solely on single organisms can fail to identify the networks underlying host-pathogen gene-for-gene interactions. Here, we integrate genetic analyses of rice (Oryza sativa, host) and rice blast fungus (Magnaporthe oryzae, pathogen) and uncover a new pathogen recognition specificity of the rice nucleotide-binding domain and leucine-rich repeat protein (NLR) immune receptor Pik, which mediates resistance to M. oryzae expressing the avirulence effector gene AVR-Pik. Rice Piks-1, encoded by an allele of Pik-1, recognizes a previously unidentified effector encoded by the M. oryzae avirulence gene AVR-Mgk1, which is found on a mini-chromosome. AVR-Mgk1 has no sequence similarity to known AVR-Pik effectors and is prone to deletion from the mini-chromosome mediated by repeated Inago2 retrotransposon sequences. AVR-Mgk1 is detected by Piks-1 and by other Pik-1 alleles known to recognize AVR-Pik effectors; recognition is mediated by AVR-Mgk1 binding to the integrated heavy metal-associated (HMA) domain of Piks-1 and other Pik-1 alleles. Our findings highlight how complex gene-for-gene interaction networks can be disentangled by applying forward genetics approaches simultaneously to the host and pathogen. We demonstrate dynamic coevolution between an NLR integrated domain and multiple families of effector proteins.


Assuntos
Oryza , Receptores Imunológicos , Receptores Imunológicos/metabolismo , Fungos/metabolismo , Doenças das Plantas/microbiologia , Interações Hospedeiro-Patógeno/genética , Oryza/genética , Oryza/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
7.
Food Microbiol ; 111: 104211, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36681393

RESUMO

Daqu is a solid-state fermentation and saccharification starter for the Chinese liquor baijou. During the daqu stage, amylolytic and proteolytic enzymes are produced by Bacillus and fungi. Bacillus spp. also produce lipopeptides with a broad spectrum of antimicrobial activities but direct evidence for their impact on community assembly in daqu is lacking. This study aimed to study the interaction between Bacillus spp. and fungi in daqu models. The antifungal activity of surfactin, fengycin, and iturin A was initially assessed in vitro. Iturin A displayed the strongest antifungal activity (MIC = 10-50 mg/L). In situ antifungal activity of B. amyloliquefaciens and B. velezensis against molds was observed in a simple daqu model inoculated with single strains of Bacillus species. Formation of lipopeptides in situ was supported by quantification of mRNA encoding for enzymes for surfactin, fengycin, and iturin A biosynthesis. In situ antifungal activity of Bacillus species was also observed in a complex daqu model that was inoculated with 8 bacterial or fungal strains plus one of the three strains of Bacillus. A relationship of lipopeptides to in situ antifungal activity was further supported by detection of the lipopeptides by liquid chromatography coupled to mass spectrometry. Both results indicated that B velezensis FUA2155 had higher antifungal activity in the daqu model, and was the only strain that produced multiple iturin A congeners in situ. Taken together, this study provides evidence that production of lipopeptides by Bacillus species in daqu may impact community assembly and hence product quality.


Assuntos
Bacillus , Bacillus/química , Antifúngicos/farmacologia , Antifúngicos/química , Fermentação , Bactérias/metabolismo , Fungos/metabolismo , Lipopeptídeos/farmacologia , Lipopeptídeos/análise , Lipopeptídeos/química
8.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674548

RESUMO

Adaptation to a wide variety of habitats allows fungi to develop unique abilities to produce diverse secondary metabolites with diverse bioactivities. In this study, 30 Ascomycetes fungi isolated from St. John's Island, Singapore were investigated for their general biosynthetic potential and their ability to produce antimicrobial secondary metabolites (SMs). All the 30 fungal isolates belong to the Phylum Ascomycota and are distributed into 6 orders and 18 genera with Order Hypocreales having the highest number of representative (37%). Screening for polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes using degenerate PCR led to the identification of 23 polyketide synthases (PKSs) and 5 nonribosomal peptide synthetases (NRPSs) grouped into nine distinct clades based on their reduction capabilities. Some of the identified PKSs genes share high similarities between species and known reference genes, suggesting the possibility of conserved biosynthesis of closely related compounds from different fungi. Fungal extracts were tested for their antimicrobial activity against S. aureus, Methicillin-resistant S. aureus (MRSA), and Candida albicans. Bioassay-guided fractionation of the active constituents from two promising isolates resulted in the isolation of seven compounds: Penilumamides A, D, and E from strain F4335 and xanthomegnin, viomellein, pretrichodermamide C and vioxanthin from strain F7180. Vioxanthin exhibited the best antibacterial activity with IC50 values of 3.0 µM and 1.6 µM against S. aureus and MRSA respectively. Viomellein revealed weak antiproliferative activity against A549 cells with an IC50 of 42 µM. The results from this study give valuable insights into the diversity and biosynthetic potential of fungi from this unique habitat and forms a background for an in-depth analysis of the biosynthetic capability of selected strains of interest with the aim of discovering novel fungal natural products.


Assuntos
Ascomicetos , Staphylococcus aureus Resistente à Meticilina , Singapura , Staphylococcus aureus Resistente à Meticilina/metabolismo , Staphylococcus aureus/metabolismo , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Ascomicetos/genética , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Fungos/metabolismo , Filogenia
9.
Toxicon ; 223: 107007, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36563862

RESUMO

Fungi are ubiquitous in distribution and are found in grasses to hot springs. Their mode of nutrition provides sustenance for living and propagation. Ironically, varied fungal species have developed customized strategies for protection and survival by producing diverse secondary metabolites. The review aimed to project the contrasting potential features of the endophytic and thermophilic fungi groups. The metabolites and the enzymes of endophytic and thermophilic fungi served as the backbone to thrive and adapt within-host and in extreme conditions like higher pH, heat, and salinity, respectively. Identification, knowledge of their biochemistry and pathway, exploration, production, and utilization of these bioactive molecules in various commercial, industrial, and pharmaceutical domains were briefly discussed. The uniqueness of endophytes includes stress management and improved biomass production of the host, green fuel production, omnipresence, selected triple-symbiosis with the virus, synthesis of polyketides, and other active metabolites are widely used in biomedical applications and agriculture management. This review attempted to limelight the specific applications of thermophilic fungal metabolites and the roles of thermo-stable enzymes in bioprospecting. Moreover, probing the metabolites of thermophiles rendered novel antibiotic compounds, which were proven effective against multi-drug resistant bacteria and harboured the potential to curtail infectious diseases.


Assuntos
Fungos , Plantas , Fungos/metabolismo , Endófitos/metabolismo , Simbiose , Biotecnologia
10.
Enzyme Microb Technol ; 164: 110173, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36529062

RESUMO

The influence of different carbon sources (glucose (G), olive oil (O), and a combination of both (GO)) in the physiology (biomass and lipase production) and morphology (light and environmental and scanning electron microscopy) of the fungus Penicillium simplicissimum by applying submerged (SmF) and solid-state (SSF) fermentations was investigated. The cultivation was carried out using polypropylene as hydrophobic inert support in SmF and SSF to understand better the influence of a support for the fungus growth and also provides the immobilization of lipases during its production. Micrographs show different morphologies: in SSF, the fungus grows on and inside the inert support independent of the media; in SmF, the formation of high-density spherical pellets obtained in medium GO leads to the best productivity and specific product yield Yp/x..Conidiation is observed mainly in SSF, a few in SmF with polypropylene as inert support and not in SmF, which may indicate a stress condition in SSF. Possibly, the morphology acquired by the fungus under stressful conditions may be the key to the higher biomass and lipase productivity at SSF. The developed process with simultaneous production and immobilization of lipase leads to a new promissory biocatalyst once it can be directly applied with no need for downstream processes.


Assuntos
Lipase , Penicillium , Lipase/metabolismo , Polipropilenos , Fermentação , Fungos/metabolismo
11.
Microbiol Res ; 268: 127280, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36563631

RESUMO

Utilization of rhizosphere microorganisms to improve plant growth and salt tolerance has recently attracted widespread attention. The growth and salt tolerance of willows inoculated with Bacillus cereus JYZ-SD2 and Peniophora cinerea XC were studied under different salt stress conditions. The results showed that the chlorophyll content of willow cuttings inoculated with the XC strain increased significantly by 51.27%. After salt stress of willow cuttings inoculated with B. cereus JYZ-SD2 and P. cinerea XC (solely or in combination), the amount of sodium in the roots from the epidermis to the pericycle decreased and the content of sodium in the pericycle was significantly lower than that of the uninoculated willow, while the proportion of potassium increased. Willow cuttings inoculated with microorganisms showed increased activity of SOD and POD. At the salt concentration of 100 mmol/L, the highest SOD activity was found in B. cereus JYZ-SD2-inoculated willows, with 59.88% increase compared to uninoculated willows; the highest POD activity was found in P. cinerea XC and B. cereus JYZ-SD2 co-inoculated willows, with 51.05% increase compared to uninoculated willows. The Na-K-ATPase and Ca-Mg-ATPase activities of inoculated P. cinerea XC willow cuttings were also 59.38% and 60% higher than that of uninoculated willows, respectively. The qPCR analysis showed that the expression of vp2 gene in the microorganism-inoculated willow leaves was always higher than that in willow alone. The expression of vp2 gene in P. cinerea XC-inoculated willow cuttings was 270.81% higher than that in uninoculated willows. Further observation of the ultrastructure of root cells under salt stress revealed that most of the vesicles in the root tip cells of willow were intact and secreted phagocytic vesicles to absorb sodium ions in the cytoplasm. This study shows that the combined beneficial fungi and rhizosphere-promoting bacteria inoculation technology as a practical biotechnological approach to enhance the growth of willows in salt-affected soils.


Assuntos
Bacillus cereus , Salix , Bacillus cereus/metabolismo , Tolerância ao Sal , Salix/metabolismo , Salix/microbiologia , Rizosfera , Estresse Salino , Fungos/metabolismo , Superóxido Dismutase/metabolismo , Adenosina Trifosfatases/metabolismo , Raízes de Plantas/microbiologia
12.
Methods Mol Biol ; 2613: 229-256, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36587083

RESUMO

Microbial glycosphingolipid (GSL)-degrading enzymes with unique specificity are useful tools for GSL research. On the other hand, some microbial glycolipids, not only GSLs but also steryl glucosides, are closely related to pathogenicity, and, thus, the metabolism of microbial glycolipids is attracting attention as a target for antibiotics. This chapter describes the assays and utilization of microbial enzymes useful for glycolipid research and those involved in pathogenicity or host immune reactions.


Assuntos
Glicolipídeos , Glicoesfingolipídeos , Glicolipídeos/metabolismo , Glicoesfingolipídeos/metabolismo , Fungos/metabolismo , Bactérias/metabolismo
13.
Chemosphere ; 314: 137688, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36584825

RESUMO

Bioremediation of mining soils using metal tolerant fungi is widely considered as a promising cost-effective and ecofriendly approach. This study assessed the copper removal efficiency and bioaccumulation ability of the indigenous species Aspergillus hiratsukae LF1 and Aspergillus terreus LF2 isolated from the soils of an abandoned copper mine in Oman. Nutrient medium containing five different Cu (II) levels (0 - control, 100, 200, 300 and 500 mg/L) was employed for assessing both parameters. The removal efficiency from nutrient medium (100-500 mg Cu per L) ranged from 57% to 21% for A. hiratsukae LF1, and from 69% to 24% for A. terreus LF2. A. hiratsukae LF1 and A. terreus LF2 accumulated a maximum of 4.63 and 5.95 mg Cu/g,espectively, at 500 mg/L of Cu (II) concentration. The compositional analysis of extracellular polymeric substances excreted by both species revealed a hormetic response by A. hiratsukae LF1 at 100 mg/L; whereas increasing media Cu levels induced carbohydrates production in A. terreus LF2. These results hint at the involvement of carbohydrates in the Cu-tolerance mechanism of the latter. Copper accumulation in both species was further demonstrated through scanning electron microscopy and energy dispersive spectrometry. In line with the pertaining literature, our results are somewhat inconclusive concerning whether proteins or carbohydrates play a more pivotal role in copper complexation in both species; yet, FTIR analysis showed the participation of different functional groups in Cu sorption. Overall, although additional research is required to advance the knowledge about both Aspergillus species, our findings suggest that A. terreus LF2 presents greater promise for copper bioremediation due to enhanced tolerance and accumulation capacity.


Assuntos
Cobre , Poluentes do Solo , Cobre/análise , Biodegradação Ambiental , Solo/química , Fungos/metabolismo , Aspergillus/metabolismo , Poluentes do Solo/análise
14.
Methods Mol Biol ; 2605: 157-168, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36520393

RESUMO

Stable isotope probing (SIP) provides the opportunity to label decomposer microorganisms that build their biomass on a specific substrate. In combination with high-throughput sequencing, SIP allows for the identification of microbial community members involved in a particular decomposition process. Further information can be gained (in SIP experiments) through gene-targeted metagenomics and metatranscriptomics, opening the possibility to describe the pool of genes catalyzing specific decomposition reactions in situ and to identify the diversity of genes that are expressed. When combined with gene descriptions of fungal and/or bacterial isolates from the same environment, specific biochemical reactions involved in decomposition can be linked to individual microbial taxa. Here, we describe the use of these methods to explore the decomposer community of fungi and bacteria in forest litter and soil.


Assuntos
Micobioma , Solo/química , Biomassa , Microbiologia do Solo , Fungos/metabolismo , Florestas , Bactérias/metabolismo
15.
Methods Mol Biol ; 2605: 79-102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36520390

RESUMO

Extraction of high-quality, high molecular weight DNA is a critical step for sequencing an organism's genome. For fungi, DNA extraction is often complicated by co-precipitation of secondary metabolites, the most destructive being polysaccharides, polyphenols, and melanin. Different DNA extraction protocols and clean-up methods have been developed to address challenging materials and contaminants; however, the method of fungal cultivation and tissue preparation also plays a critical role to limit the production of inhibitory compounds prior to extraction. Here, we provide protocols and guidelines for (i) fungal tissue cultivation and processing with solid media containing a cellophane overlay or in liquid media, (ii) DNA extraction with customized recommendations for taxonomically and ecologically diverse plant-associated fungi, and (iii) assessing DNA quantity and quality for downstream genome sequencing with single-molecule technology such as PacBio.


Assuntos
Fungos , Genoma , DNA Fúngico/genética , DNA Fúngico/metabolismo , Peso Molecular , Fungos/genética , Fungos/metabolismo , Mapeamento Cromossômico
16.
Adv Sci (Weinh) ; 10(3): e2204308, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36515275

RESUMO

To date, viroids have been found to naturally infect only plants, resulting in substantial losses for some crops. Whether viroids or viroid-like RNAs naturally infect non-plant hosts remains unknown. Here the existence of a set of exogenous, single-stranded circular RNAs, ranging in size from 157 to 450 nucleotides, isolated from the fungus Botryosphaeria dothidea and nominated B. dothidea RNAs (BdcRNAs) is reported. BdcRNAs replicate autonomously in the nucleus via a rolling-circle mechanism following a symmetric pathway. BdcRNA infection induces symptoms, because BdcRNAs can apparently modulate, to different degrees, specific biological traits (e.g., alter morphology, decrease growth rate, attenuate virulence, and increase or decrease tolerance to osmotic and oxidative stress) of the host fungus. Overall, BdcRNAs have genome characteristics similar to those of viroids and exhibit pathogenic effects on fungal hosts. It is proposed that these novel fungus infecting RNAs should be termed mycoviroids. BdcRNA(s) may be considered additional inhabitants at the frontier of life in terms of genomic complexity, and represent a new class of acellular entities endowed with regulatory functions, and novel epigenomic carriers of biological information.


Assuntos
Viroides , Viroides/genética , Viroides/metabolismo , RNA Viral/genética , Plantas , Fungos/genética , Fungos/metabolismo
17.
J Mol Biol ; 434(4): 167273, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-34599942

RESUMO

The gasdermin family of pore-forming proteins (PFPs) has recently emerged as key molecular players controlling immune-related cell death in mammals. Characterized mammalian gasdermins are activated through proteolytic cleavage by caspases or serine proteases, which remove an inhibitory carboxy-terminal domain, allowing the pore-formation process. Processed gasdermins form transmembrane pores permeabilizing the plasma membrane, which often results in lytic and inflammatory cell death. While the gasdermin-dependent cell death (pyroptosis) has been predominantly characterized in mammals, it now has become clear that gasdermins also control cell death in early vertebrates (teleost fish) and invertebrate animals such as corals (Cnidaria). Moreover, gasdermins and gasdermin-like proteins have been identified and characterized in taxa outside of animals, notably Fungi and Bacteria. Fungal and bacterial gasdermins share many features with mammalian gasdermins including their mode of activation through proteolysis. It has been shown that in some cases the proteolytic activation is executed by evolutionarily related proteases acting downstream of proteins resembling immune receptors controlling pyroptosis in mammals. Overall, these findings establish gasdermins and gasdermin-regulated cell death as an extremely ancient mechanism of cellular suicide and build towards an understanding of the evolution of regulated cell death in the context of immunology. Here, we review the broader gasdermin family, focusing on recent discoveries in invertebrates, fungi and bacteria.


Assuntos
Bactérias , Caspases , Fungos , Invertebrados , Proteínas Citotóxicas Formadoras de Poros , Piroptose , Animais , Bactérias/metabolismo , Caspases/metabolismo , Fungos/metabolismo , Humanos , Invertebrados/metabolismo , Peptídeo Hidrolases/metabolismo , Porinas , Piroptose/fisiologia
18.
Molecules ; 27(23)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36500394

RESUMO

Marine-derived fungi are important sources of novel compounds and pharmacologically active metabolites. As an important class of natural products, diterpenes show various biological activities, such as antiviral, antibacterial, anti-inflammatory, antimalarial, and cytotoxic activities. Developments of equipment for the deep-sea sample collection allow discoveries of more marine-derived fungi with increasing diversity, and much progress has been made in the identification of diterpenes with novel structures and bioactivities from marine fungi in the past decade. The present review article summarized the chemical structures, producing organisms and biological activities of 237 diterpenes which were isolated from various marine-derived fungi over the period from 2009 to 2021. This review is beneficial for the exploration of marine-derived fungi as promising sources of bioactive diterpenes.


Assuntos
Antimaláricos , Produtos Biológicos , Diterpenos , Fungos/metabolismo , Produtos Biológicos/química , Diterpenos/farmacologia , Diterpenos/metabolismo , Antimaláricos/química , Antibacterianos/química , Organismos Aquáticos/química
19.
Int J Mol Sci ; 23(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36555267

RESUMO

In this opinion article, we have analyzed the relevancy of a hypothesis which is based on the idea that in Arabidopsis thaliana jasmonic acid, a (JA)-mediated defense system against necrotrophic fungi is weakened when NO3- supply is high. Such a hypothesis is based on the fact that when NO3- supply is high, it induces an increase in the amount of bioactive ABA which induces the sequestration of the phosphatase ABI2 (PP2C) into the PYR/PYL/RCAR receptor. Consequently, the Ca sensors CBL1/9-CIPK23 are not dephosphorylated by ABI2, thus remaining able to phosphorylate targets such as AtNPF6.3 and AtKAT1, which are NO3- and K+ transporters, respectively. Therefore, the impact of phosphorylation on the regulation of these two transporters, could (1) reduce NO3- influx as in its phosphorylated state AtNPF6.3 shifts to low capacity state and (2) increase K+ influx, as in its phosphorylated state KAT1 becomes more active. It is also well known that in roots, K+ loading in the xylem and its transport to the shoot is activated in the presence of NO3-. As such, the enrichment of plant tissues in K+ can impair a jasmonic acid (JA) regulatory pathway and the induction of the corresponding biomarkers. The latter are known to be up-regulated under K+ deficiency and inhibited when K+ is resupplied. We therefore suggest that increased K+ uptake and tissue content induced by high NO3- supply modifies the JA regulatory pathway, resulting in a weakened JA-mediated plant's defense system against necrotrophic fungi.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Canais de Potássio Corretores do Fluxo de Internalização , Nitratos/metabolismo , Potássio/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Membrana Transportadoras/metabolismo , Fungos/metabolismo , Regulação da Expressão Gênica de Plantas , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo
20.
J Agric Food Chem ; 70(51): 16037-16049, 2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36511327

RESUMO

Characterized by strong acidity, chelating ability, and reducing ability, oxalic acid, a low molecular weight dicarboxylic organic acid, plays important roles in the regulation of plant growth and development, the response to both biotic and abiotic stresses such as plant defense and heavy metals detoxification, and food quality. The metabolism of oxalic acid has been well-studied in microorganisms, fungi, and animals but remains less understood in plants. However, excessive accumulation of oxalic acid is detrimental to plants. Therefore, the level of oxalic acid has to be precisely controlled in plant tissues. In this review, we summarize the metabolism, function, and regulation of oxalic acid in plants, and we discuss solutions such as agricultural practices and plant biotechnology to manipulate oxalic acid metabolism to regulate plant responses to both external stimuli and internal developmental cues.


Assuntos
Metais Pesados , Plantas , Animais , Plantas/metabolismo , Ácido Oxálico/metabolismo , Fungos/metabolismo , Biotecnologia , Metais Pesados/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...