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1.
PLoS Pathog ; 20(7): e1012431, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39078845

RESUMO

Reactive carbonyl and oxygen species (RCS/ROS), often generated as metabolic byproducts, particularly under conditions of pathology, can cause direct damage to proteins, lipids, and nucleic acids. Glyoxal oxidases (Gloxs) oxidize aldehydes to carboxylic acids, generating hydrogen peroxide (H2O2). Although best characterized for their roles in lignin degradation, Glox in plant fungal pathogens are known to contribute to virulence, however, the mechanism underlying such effects are unclear. Here, we show that Glox in the insect pathogenic fungus, Metarhizium acridum, is highly expressed in mycelia and during formation of infection structures (appressoria), with the enzyme localizing to the cell membrane. MaGlox targeted gene disruption mutants showed RCS and ROS accumulation, resulting in cell toxicity, induction of apoptosis and increased autophagy, inhibiting normal fungal growth and development. The ability of the MaGlox mutant to scavenge RCS was significantly reduced, and the mutant exhibited increased susceptibility to aldehydes, oxidative and cell wall perturbing agents but not toward osmotic stress, with altered cell wall contents. The ΔMaGlox mutant was impaired in its ability to penetrate the host cuticle and evade host immune defense resulting in attenuated pathogenicity. Overexpression of MaGlox promoted fungal growth and conidial germination, increased tolerance to H2O2, but had little to other phenotypic effects. Transcriptomic analyses revealed downregulation of genes related to cell wall synthesis, conidiation, stress tolerance, and host cuticle penetration in the ΔMaGlox mutant. These findings demonstrate that MaGlox-mediated scavenging of RCS is required for virulence, and contributes to normal fungal growth and development, stress resistance.


Assuntos
Oxirredutases do Álcool , Proteínas Fúngicas , Metarhizium , Virulência , Oxirredutases do Álcool/metabolismo , Oxirredutases do Álcool/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Metarhizium/patogenicidade , Metarhizium/genética , Metarhizium/metabolismo , Animais , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Estresse Oxidativo
2.
Appl Microbiol Biotechnol ; 107(9): 2969-2982, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36941435

RESUMO

Carbon sources and their utilization are vital for fungal growth and development. C4-dicarboxylic acids are important carbon and energy sources that function as intermediate products of the tricarboxylic acid cycle. Transport and regulation of C4-dicarboxylic acid uptake are mainly dependent on tetracarboxylic acid transporters (Dcts) in many microbes, although the roles of Dct genes in fungi have only been partially characterized. Here, we report on the functions of two Dct genes (Dct1 and Dct2) in the entomopathogenic fungus Metarhizium acridum. Our data showed that loss of the MaDct1 gene affected utilization of tetracarboxylic acids and other carbon sources. ΔMaDct1 mutants showed larger colony sizes with extensive mycelial growth but were delayed in conidiation with decreased conidia yield as compared to the wild-type parental strain. On the nutrient-deficient medium, SYA, the wild-type strain produced microcycle conidia, whereas the ΔMaDct1 mutant produced (normal) aerial conidia. In addition, ΔMaDct1 had decreased tolerance to cell wall perturbing agents, but increased tolerances to UV-B radiation and osmotic stress. Insect bioassays indicated that loss of MaDct1 did not affect pathogenicity. In contrast, no distinct phenotypic change was observed for the MaDct2 mutant in terms of growth and biocontrol characteristics. Transcriptomic profiling between wild type and ΔMaDct1 showed that differentially expressed genes were enriched in carbohydrate and amino acid metabolism, transport and catabolism, and signal transduction. These results demonstrate that MaDct1 regulates the conidiation pattern shift and mycelial growth by affecting utilization of carbon sources. These findings are helpful for better understanding the effect of intermediates of carbon metabolism on fungal growth and conidiation. KEY POINTS: • MaDct1 influences fungal growth and conidiation by affecting carbon source utilization. • MaDct1 regulates conidiation pattern shift under nutrient deficiency condition. • MaDct1 is involved in stress tolerance and has no effect on virulence. • MaDct2 has no effect on growth and biocontrol characteristic.


Assuntos
Regulação Fúngica da Expressão Gênica , Metarhizium , Perfilação da Expressão Gênica , Virulência , Proteínas de Membrana Transportadoras/metabolismo , Esporos Fúngicos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
3.
J Plant Res ; 136(3): 359-369, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36881276

RESUMO

Pinellia ternata (Thunb.) Breit. is an important traditional Chinese medicinal herb and very sensitive to high temperatures. To gain a better understanding of flavonoid biosynthesis under heat stress in P. ternata, we performed integrated analyses of metabolome and transcriptome data. P. ternata plants were subjected to a temperature of 38 °C, and samples were collected after 10 d of treatment. A total of 502 differential accumulated metabolites and 5040 different expressed transcripts were identified, with flavonoid biosynthesis predominantly enriched. Integrated metabolomics and transcriptome analysis showed that high temperature treatment upregulated the expression of CYP73A and downregulated the expression of other genes (such as HCT, CCoAOMT, DFR1, DFR2), which might inhibit the biosynthesis of the downstream metabolome, including such metabolites as chlorogenic acid, pelargonidin, cyanidin, and (-)-epigallocatechin in the flavonoid biosynthesis pathway. The transcription expression levels of these genes were validated by real-time PCR. Our results provide valuable insights into flavonoid composition and accumulation patterns and the candidate genes participating in the flavonoid biosynthesis pathways under heat stress in P. ternata.


Assuntos
Pinellia , Transcriptoma , Pinellia/genética , Pinellia/metabolismo , Resposta ao Choque Térmico , Metaboloma , Flavonoides/metabolismo
4.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 48(2): 198-205, 2023 Feb 28.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-36999466

RESUMO

OBJECTIVES: The number of gestational women has been increased in recent years, resulting in more adverse pregnancy outcomes. It is crucial to assess the coagulation function of pregnant women and to intervene in a timely manner. This study aims to analyze the influencing factors on thrombelastography (TEG) and explore the evaluation of TEG for gestational women. METHODS: A retrospective study was conducted on 449 pregnant women who were hospitalized in the obstetrics department in Xiangya Hospital of Central South University from 2018 to 2020. We compared the changes on the TEG parameters among normal pregnant women between different age groups, different ingravidation groups, and different stages of pregnancy groups. The influence on TEG of hypertensive disorders in pregnancy (HDP) and gestational diabetes mellitus (GDM) as well as two diseases synchronization was explored. RESULTS: Compared with the normal second trimester women, the R values and K values of TEG were increased, and α angle, CI values and LY30 values were decreased in third trimester women (all P<0.05). Compared with normal group, the R values and CI values of TEG of the HDP group have significant difference (both P<0.05). There were no significant difference of TEG between the GDM group, the HDP combined with GDM group and the normal group (all P>0.05). Multiple linear regression analysis showed that the influencing factors for R value in TEG were weeks of gestation (P<0.001) and mode of conception (P<0.05), for α angle was weeks of gestation (P<0.05), for MA value was mode of conception (P<0.05), and for CI value was weeks of gestation (P<0.05). The analysis of correlation between TEG with platelet (PLT) and coagulation routines represented that there was a correlation between TEG R values and activated partial thromboplastin time (APTT) (P<0.01), and negative correlation between TEG CI values and APTT (P<0.05). There was a negative correlation between TEG K values and FIB (P<0.05). The correlation of α angle (P<0.05), MA values (P<0.01) and CI values (P<0.05) with FIB were positive respectively. CONCLUSIONS: The TEG parameters of 3 stages of pregnancy were different. The different ingravidation approach has effect on TEG. The TEG parameters were consistent with conventional coagulation indicators. The TEG can be used to screen the coagulation status of gestational women, recognize the abnormalities of coagulation and prevent the severe complication timely.


Assuntos
Diabetes Gestacional , Tromboelastografia , Feminino , Humanos , Gravidez , Tromboelastografia/métodos , Testes de Coagulação Sanguínea/métodos , Estudos Retrospectivos , Coagulação Sanguínea , Plaquetas , Diabetes Gestacional/diagnóstico
5.
Environ Microbiol ; 24(7): 2951-2961, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35384250

RESUMO

Conidiation necessary for filamentous fungal survival and dispersal proceeds in two fashions, namely, normal conidiation through conidiophores differentiated from hyphae and microcycle conidiation through conidial budding. Normal conidiation has been well studied, whereas mechanisms underlying microcycle conidiation are still largely unknown. Here, we report that a gene (MaNsdD) homologous to NsdD in Aspergillus nidulans serves as a suppressor of normal conidiation but a positive regulator of hyphal development in Metarhizium acridum. Disruption of MaNsdD (ΔMaNsdD) resulted in microcycle conidiation and significantly descended in conidial resistance to heat while improved to UV irradiation. Transcriptomic analysis revealed that many genes involved in conidiation, cell division and cell wall formation were differentially expressed in ΔMaNsdD, and likely associated with the conidiation process. We found that a gene (MaAbaA) homologous to the core asexual development regulator AbaA in A. nidulans was negatively controlled by MaNsdD. Disruption of MaAbaA led to the abolition of the conidiation process of M. acridum. These findings unravel a novel regulatory mechanism of microcycle conidiation and add knowledge to the asexual conidiation pathway of filamentous fungi.


Assuntos
Aspergillus nidulans , Metarhizium , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Metarhizium/metabolismo , Esporos Fúngicos/metabolismo
6.
Appl Environ Microbiol ; 87(19): e0090821, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34288712

RESUMO

Filamentous fungi conduct two types of conidiation, typical conidiation from mycelia and microcycle conidiation (MC). Fungal conidiation can shift between the two patterns, which involves a large number of genes in the regulation of this process. In this study, we investigated the role of a dipeptidase gene pepdA in conidiation pattern shift in Metarhizium acridum, which is upregulated in MC pattern compared to typical conidiation. Results showed that disruption of the pepdA resulted in a shift of conidiation pattern from MC to typical conidiation. Metabolomic analyses of amino acids showed that the levels of 19 amino acids significantly changed in ΔpepdA mutant. The defect of MC in ΔpepdA can be rescued when nonpolar amino acids, α-alanine, ß-alanine, or proline, were added into sucrose yeast extract agar (SYA) medium. Digital gene expression profiling analysis revealed that PEPDA mediated transcription of sets of genes which were involved in hyphal growth and development, sporulation, cell division, and amino acid metabolism. Our results demonstrated that PEPDA played important roles in the regulation of MC by manipulating the levels of amino acids in M. acridum. IMPORTANCE Conidia, as the asexual propagules in many fungi, are the start and end of the fungal life cycle. In entomopathogenic fungi, conidia are the infective form essential for their pathogenicity. Filamentous fungi conduct two types of conidiation, typical conidiation from mycelia and microcycle conidiation. The mechanisms of the shift between the two conidiation patterns remain to be elucidated. In this study, we demonstrated that the dipeptidase PEPDA, a key enzyme from the insect-pathogenic fungus Metarhizium acridum for the hydrolysis of dipeptides, is associated with a shift of conidiation pattern. The conidiation pattern of the ΔpepdA mutant was restored when supplemented with the nonpolar amino acids rather than polar amino acids. Therefore, this report highlights that the dipeptidase PEPDA regulates MC by manipulating the levels of amino acids in M. acridum.


Assuntos
Dipeptidases/genética , Proteínas Fúngicas/genética , Metarhizium , Esporos Fúngicos/crescimento & desenvolvimento , Aminoácidos/genética , Dipeptidases/metabolismo , Dipeptídeos/metabolismo , Proteínas Fúngicas/metabolismo , Metarhizium/enzimologia , Metarhizium/genética , Metarhizium/fisiologia
7.
J Invertebr Pathol ; 182: 107565, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33676966

RESUMO

Entomopathogenic fungi have been used as important biological control agents throughout the world. To improve the biocontrol efficacy of entomopathogenic fungi, many genes have been used to improve fungal virulence or tolerance to adverse conditions via modulating their expression with strong promoters. The Magas1 gene is specifically expressed during appressorium formation and contributes to the virulence in Metarhizium acridum. In this study, we analyzed the functional region of the promoter of Magas1 gene (PMagas1) in M. acridum using 5'-deletion technique with enhanced green fluoresces protein (EGFP) as a reporter. Results showed the full length of the PMagas1 was at least 897 bp. Two regions (-897 to -611 bp and -392 to -328 bp) were essential for the activity of PMagas1. An engineered M. acridum strain was constructed with PMagas1 driving the expression of a subtilisin-like proteinase gene Pr1A (PMagas1-PR1A). Bioassay showed that the virulence was significantly increased in PMagas1-PR1A strain compared to wild type strain. Pmagas1 promoter is suitable for the overexpression of some genes during the infection of entomopathogenic fungi, which avoids the waste of nutritional resources and the influence on other fungal characteristics during the saprophytic process of constitutive promoter.


Assuntos
Proteínas Fúngicas/genética , Metarhizium/genética , Metarhizium/patogenicidade , Proteínas Fúngicas/metabolismo , Virulência/genética
8.
Appl Microbiol Biotechnol ; 103(4): 1801-1810, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30617534

RESUMO

Calcium signaling plays important roles in stress tolerance and virulence in fungi. Mid1, an accessory protein of Cch1 calcium channel, has been discussed in baker's yeast and some filamentous fungi. However, functions of the Mid1 gene in entomopathogenic fungi are not clear. In this study, the Mid1 gene was functionally characterized by deleting it in the entomopathogenic fungus Metarhizium acridum. The growth of the ΔMaMid1 mutant was similar as the wild type on normal growth medium, but inhibited by exogenous Ca2+, Fe2+, Mg2+, Mn2+, Li+, and calcium chelator ethylene glycol tetraacetic acid (EGTA). Cation transportation-related genes were upregulated and intracellular calcium concentration was decreased in ΔMaMid1. Deletion of the MaMid1 gene impaired the tolerance to cell wall-disrupting agents but had no impact on heat or ultraviolet irradiation tolerance compared with the wild type. Bioassays showed that ΔMaMid1 had decreased virulence, with defects in the ability to penetrate the host cuticle. Compared with the wild type, appressorium formation on locust wings and fungal growth in the insect hemocoel were significantly decreased in the ΔMaMid1 mutant in a bioassay through topical inoculation. The phenotypes of ΔMaMid1 were fully restored in a complementation strain. Taken together, our study demonstrates that the MaMid1 affects intracellular ion homeostasis and contributes to virulence by affecting the initial penetration process in M. acridum.


Assuntos
Parede Celular/metabolismo , Proteínas Fúngicas/metabolismo , Transporte de Íons , Metarhizium/crescimento & desenvolvimento , Metarhizium/metabolismo , Animais , Bioensaio , Meios de Cultura/química , Proteínas Fúngicas/genética , Deleção de Genes , Teste de Complementação Genética , Insetos , Metarhizium/genética , Virulência , Asas de Animais/microbiologia
10.
World J Microbiol Biotechnol ; 34(6): 78, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29796938

RESUMO

GTPase activation protein (GAP) for Rab GTPases can accelerate GTP hydrolysis to alter the activity of Rab GTPases. To explore the function of GAP in entomopathogenic fungi, we constructed a deletion mutant of Gyp2 gene, a member of the Gyp (GAP for Ypt/Rab proteins) family in the locust-specific fungal pathogen, Metarhizium acridum. Results showed that the ∆MaGyp2 mutant had dramatically decreased tolerance to ultraviolet irradiation compared to wild type strain. Quantitative real-time PCR revealed that UV irradiation repair related genes Uve1 and WC1 were downregulated in ∆MaGyp2 mutant. Seven of other ten Gyp family members had significantly increased transcription in ∆MaGyp2 mutant compared with wild type, which may partly rescue the deficiency of MaGyp2.


Assuntos
Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/fisiologia , Metarhizium/genética , Metarhizium/fisiologia , Metarhizium/efeitos da radiação , Tolerância a Radiação/genética , Tolerância a Radiação/fisiologia , Raios Ultravioleta , Sequência de Aminoácidos , Animais , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas Ativadoras de GTPase/química , Deleção de Genes , Regulação Fúngica da Expressão Gênica , Genes Fúngicos/genética , Gafanhotos/microbiologia , Metarhizium/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos , Estresse Psicológico , Virulência
11.
Environ Microbiol ; 19(10): 4365-4378, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28925548

RESUMO

Microbial pathogens are exposed to damaging reactive oxygen species (ROS) produced from a variety of sources including chemical reactions due to exposure to stress (UV, heat) or by hosts as a defense response. Here, we demonstrate that a bifunctional catalase-peroxidase, MakatG1, in the locust-specific fungal pathogen, Metarhizium acridum, functions as a ROS detoxification mechanism during host cuticle penetration. MakatG1 expression was highly induced during on-cuticle appressoria development as compared to vegetative (mycelia) growth or during in vivo growth in the insect hemocoel. A MakatG1 deletion mutant strain (ΔMakatG1) showed decreased catalase and peroxidase activities and significantly increased susceptibility to oxidative (H2 O2 and menadione) and UV stress as compared to wild-type and complemented strains. Insect bioassays revealed significantly reduced virulence of the ΔMakatG1 mutant when topically inoculated, but no impairment when the insect cuticle was bypassed. Germination and appressoria formation rates for the ΔMakatG1 mutant were decreased on locust wings and quinone/phenolic compounds derived from locust wings, but were not affected on plastic surfaces compared with the wild-type strain. These data indicate that MakatG1 plays a pivotal role in penetration, reacting to and detoxifying specific cuticular compounds present on the host cuticle during the early stages of fungal infection.


Assuntos
Catalase/genética , Gafanhotos/microbiologia , Metarhizium/enzimologia , Metarhizium/patogenicidade , Peroxidases/genética , Animais , Catalase/metabolismo , Deleção de Genes , Peróxido de Hidrogênio/metabolismo , Micélio/metabolismo , Estresse Oxidativo , Peroxidases/metabolismo , Virulência , Vitamina K 3/metabolismo
12.
Appl Microbiol Biotechnol ; 101(12): 5033-5043, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28424845

RESUMO

In fungi, the Ca2+/calcineurin signaling pathway is critical in mediating growth, morphology, stress responses, and pathogenicity. Crz1 is a calcineurin-responsive zinc finger transcription factor. Here, MaCrz1 was identified and functionally characterized in the entomopathogenic fungus Metarhizium acridum by characterization of a targeted gene knockout strain. Conidia of the ΔMacrz1 mutant were aberrant in cell surface features and lacked the characteristic hydrophobic rodlet layer, and the mutant displayed increased sensitivity to oxidative stress, cell wall perturbing agents, heat stress, and ultraviolet irradiation as compared to the wild-type and complemented strains. Insect bioassay using locusts revealed decreased virulence for the ΔMaCrz1 mutant, with defects in the ability of the mutant to penetrate the host cuticle. The ΔMaCrz1 mutant also showed greatly reduced chitin and ß-1,3-glucan level in the cell wall. Transcriptomic profiling revealed genes involved in cell wall synthesis, conidiation, stress tolerance, and calcium transport that were downregulated in the ΔMaCrz1 mutant. Our results demonstrate that MaCrz1 plays important roles in stress susceptibility and pathogenicity, and provides clues as to the genes and pathways targeted by the transcription factor.


Assuntos
Regulação Fúngica da Expressão Gênica , Metarhizium/genética , Metarhizium/fisiologia , Estresse Oxidativo/genética , Fatores de Transcrição/metabolismo , Animais , Calcineurina/genética , Cálcio/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Gafanhotos/microbiologia , Metarhizium/metabolismo , Metarhizium/patogenicidade , Mutação , Transdução de Sinais , Esporos Fúngicos/crescimento & desenvolvimento , Fatores de Transcrição/genética , Virulência , Dedos de Zinco
13.
J Invertebr Pathol ; 139: 19-24, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27345377

RESUMO

Hemocytes are the first line of defense in the invertebrate immune system. Understanding their roles in cellular immunity is important for developing more efficient mycoinsecticides. However, the exact classification of hemocytes has been inconsistent and the various types of phagocytes in Locusta migratoria are poorly defined. Herein, the Wright-Giemsa staining method and microscopy were employed to characterize the hemocytes of L. migratoria following infection by Metarhizium acridum. Hemocytes were classified into four types, including granulocytes, plasmatocytes, prohemocytes, and oenocytoids, based on size, morphology, and dye-staining properties. Each type of hemocyte was classified into several subtypes according to different ultrastructural features. At least four subtypes of granulocytes or plasmatocytes, including small-nucleus plasmatocytes, basophil vacuolated plasmatocytes, homogeneous plasmatocytes, and eosinophilic granulocytes, carried out phagocytosis. The percentage of total phagocytes increased two days after infection by M. acridum, then gradually declined during the next two days, and then increased sharply again at the fifth day. Our data suggested that plasmatocytes and granulocytes may be the major phagocytes that protect against invasion by a fungal pathogen in L. migratoria. Total hemocytes in locusts significantly increased in the initial days after infection and decreased in the late period of infection compared to controls. In the hemocoel, hyphal bodies were recognized, enwrapped, and digested by the phagocytes. Then, the broken hyphal pieces were packaged as vesicles to be secreted from the cell. Moreover, locusts might have a sensitive and efficient cellular immune system that can regulate phagocyte differentiation and proliferation before fungi colonize the host hemolymph.


Assuntos
Hemócitos/classificação , Locusta migratoria/imunologia , Fagócitos/classificação , Coloração e Rotulagem/métodos , Animais , Hemócitos/citologia , Locusta migratoria/citologia , Locusta migratoria/parasitologia , Masculino , Metarhizium , Micoses/veterinária , Fagócitos/citologia
14.
Appl Microbiol Biotechnol ; 98(19): 8253-65, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24931310

RESUMO

Calcineurin is highly conserved and regulates growth, conidiation, stress response, and pathogenicity in fungi. However, the functions of calcineurin and its regulatory network in entomopathogenic fungi are not clear. In this study, calcineurin was functionally analyzed by deleting the catalytic subunit MaCnA from the entomopathogenic fungus Metarhizium acridum. The ΔMaCnA mutant had aberrant, compact colonies and blunt, shortened hyphae. Conidia production was reduced, and phialide differentiation into conidiogenous cells was impaired in the ΔMaCnA mutant. ΔMaCnA had thinner cell walls and greatly reduced chitin and ß-1,3-glucan content compared to the wild type. The ΔMaCnA mutant was more tolerant to cell wall-perturbing agents and elevated or decreased exogenous calcium but less tolerant to heat, ultraviolet irradiation, and caspofungin than the wild type. Bioassays showed that ΔMaCnA had decreased virulence. Digital gene expression profiling revealed that genes involved in cell wall construction, conidiation, stress tolerance, cell cycle control, and calcium transport were downregulated in ΔMaCnA. Calcineurin affected some components of small G proteins, mitogen-activated protein kinase, and cyclic AMP (cAMP)-protein kinase A signaling pathways in M. acridum. In conclusion, our results gave a global survey of the genes downstream of calcineurin in M. acridum, providing molecular explanations for the changes in phenotypes observed when calcineurin was deleted.


Assuntos
Calcineurina/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Locusta migratoria/microbiologia , Metarhizium/enzimologia , Metarhizium/patogenicidade , Esporos Fúngicos/crescimento & desenvolvimento , Animais , Calcineurina/genética , Proteínas Fúngicas/genética , Metarhizium/genética , Metarhizium/crescimento & desenvolvimento , Dados de Sequência Molecular , Esporos Fúngicos/enzimologia , Esporos Fúngicos/genética , Esporos Fúngicos/patogenicidade , Virulência
15.
Insect Sci ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38389031

RESUMO

The use of insecticides, primarily pyrethroids, is a pivotal strategy for mosquito control globally. Bioallethrin, the first commercially available volatile pyrethroid, can elicit spatial (i.e., noncontact) repellency to mosquitoes through the coactivation of olfactory receptor neurons and sodium channels. However, the olfactory mechanism of the repellency elicited by bioallethrin in mosquitoes is still unclear. Here, we demonstrated the involvement of AsOBP1 in the bioallethrin repellency in Anopheles sinensis, one of the main vectors of vivax malaria in China and other Southeast Asian countries. The behavioral and electrophysiological analyses in AsOrco-/- mutant found that the spatial repellency elicited by bioallethrin depended on the odorant receptor (OR)-mediated olfactory pathway. Furthermore, the repellency was reduced in the AsOBP1-/- mutant and a pyrethroid-resistant strain, in which the expression of AsOBP1 was significantly decreased. Moreover, recombinant AsOBP1 protein bound to bioallethrin in an in vitro competition assay. These results indicate that activation of the AsOBP1-mediated olfactory pathway is an important component of bioallethrin repellency. Our research lays the foundation for further elucidation into the olfactory mechanism of bioallethrin repellency and the behavioral modifications of pyrethroid-resistant mosquitoes.

16.
Environ Microbiol ; 15(11): 2966-79, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23809263

RESUMO

In most eukaryotes, tetraspanins regulate cellular activities by associating with other membrane components. In phytopathogenic fungi, the tetraspanin Pls1 controls appressorium-mediated penetration. However, regulation of Pls1 and its associated signalling pathways are not clear. In this study, the MaPls1 gene from the entomopathogenic fungus Metarhizium acridum was functionally characterized. MaPls1 was highly expressed in mycelium and appressorium, and accumulated on the plasma membrane or in the cytoplasm. Compared with a wild-type strain, the deletion mutant ΔMaPls1 had delayed germination and appressorium formation and impaired turgor pressure on locust wings, but normal germination on medium and non-host insect matrices. Bioassays showed that ΔMaPls1 had decreased virulence and hyphal body formation in haemolymph when topically inoculated, but was not different from wild type when the insect cuticle was bypassed. Moreover, the ability to grow out of the cuticle was impaired in ΔMaPls1. Digital gene expression profiling revealed that genes involved in hydrolysing host cuticle and cell wall synthesis and remodelling were downregulated in ΔMaPls1. MaPls1 participated in crosstalk with signalling pathways such as the cyclic adenosine monophosphate-dependent protein kinase A and calmodulin-dependent pathways. Taken together, these results demonstrated the important roles of MaPls1 at the early stage of infection-associated development in M. acridum.


Assuntos
Insetos/microbiologia , Metarhizium/genética , Metarhizium/patogenicidade , Tetraspaninas/genética , Fatores de Virulência/genética , Animais , Sequência de Bases , Calmodulina/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , DNA Fúngico/análise , DNA Fúngico/genética , Deleção de Genes , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica/genética , Micélio/metabolismo , Análise de Sequência de DNA , Transdução de Sinais/genética , Virulência/genética
17.
J Fungi (Basel) ; 9(7)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37504734

RESUMO

Fungal diseases are widespread among insects and play a crucial role in naturally regulating insect populations. Mosquitoes, known as vectors for numerous infectious diseases, pose a significant threat to human health. Entomopathogenic fungi (EPF) have emerged as highly promising alternative agents to chemical mosquitocides for controlling mosquitoes at all stages of their life cycle due to their unique infection pathway through direct contact with the insect's cuticle. In recent years, significant advancements have been made in understanding the infection pathways and pathogenic mechanisms of EPF against mosquitoes. Various strategies involving the use of EPF alone or combinations with other approaches have been employed to target mosquitoes at various developmental stages. Moreover, the application of genetic technologies in fungi has opened up new avenues for enhancing the mosquitocidal efficacy of EPF. This review presents a comprehensive summary of recent advancements in our understanding the pathogenic mechanisms of EPF, their applications in mosquito management, and the combination of EPF with other approaches and employment of transgenic technologies. The biosafety concerns associated with their use and the corresponding approaches are also discussed. The recent progress suggests that EPF have the potential to serve as a future biorational tool for controlling mosquito vectors.

18.
J Adv Res ; 48: 1-16, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36064181

RESUMO

INTRODUCTION: Odorant-binding proteins (OBPs) are a class of small molecular weight soluble proteins that exist as expanded gene families in all insects, acting as ligand carriers mediating olfaction and other physiological processes. During fungal infection, a subset of insect OBPs were shown to be differentially expressed. OBJECTIVES: We tested whether the altered expression of insect OBPs during pathogenic infection plays a role in behavioral or immune interactions between insect hosts and their pathogens. METHODS: A wide range of techniques including RNAi-directed knockdown, heterologous protein expression, electrophysiological/behavioral analyses, transcriptomics, gut microbiome analyses, coupled with tandem mass spectrometry ion monitoring, were used to characterize the function of a locust OBP in host behavioral and immune responses. RESULTS: The entomopathogenic fungus Metarhizium anisopliae produces the volatile compound phenylethyl alcohol (PEA) that causes behavioral avoidance in locusts. This is mediated by the locust odorant binding protein 11 (LmOBP11). Expression of LmOBP11 is induced by M. anisopliae infection and PEA treatment. LmOBP11 participates in insect detection of the fungal-produced PEA and avoidance of PEA-contaminated food, but the upregulation of LmOBP11 upon M. anisopliae infection negatively affects the insect immune responses to ultimately benefit successful mycosis by the pathogen. RNAi knockdown of LmOBP11 increases the production of antimicrobial peptides and enhances locust resistance to M. anisopliae infection, while reducing host antennal electrophysiological responses to PEA and locust avoidance of PEA treated food. Also, transcriptomic and gut microbiome analyses reveal microbiome dysbiosis and changes in host genes involved in behavior and immunity. These results are consistent with the elevated expression of LmOBP11 leading to enhanced volatile detection and suppression of immune responses. CONCLUSION: These findings suggest a crosstalk between olfaction and immunity, indicating manipulation of host OBPs as a novel target exploited by fungal pathogens to alter immune activation and thus promote the successful infection of the host.


Assuntos
Gafanhotos , Metarhizium , Micoses , Animais , Odorantes , Insetos/microbiologia , Gafanhotos/microbiologia , Metarhizium/fisiologia , Imunidade Inata
19.
Biotechnol Lett ; 34(3): 557-62, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22109936

RESUMO

A glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter (PMagpd) was obtained from Metarhizium acridum and its active region analyzed by 5'-deletion strategy using ß-glucuronidase (GUS) as a reporter. Sequence analysis revealed that typical regulatory elements of PMagpd were included in the 1.7 kb region upstream of the start codon of the Magpd gene. Deletion of the region from -1,691 bp to -1,463 bp, where the gpd box is harbored, did not significantly affect the PMagpd activity. Deletions of the regions upstream of -946 bp and upstream of -684 bp caused a major decrease of GUS activity. Compared with PgpdA (2.2 kb) in Aspergillus nidulans, PMagpd (1.4 kb) had a shorter sequence and significantly higher activity in M. acridum. This study provides an applicable promoter for over-expression of target genes in M. acridum.


Assuntos
Expressão Gênica , Metarhizium/genética , Regiões Promotoras Genéticas , Fusão Gênica Artificial , Aspergillus nidulans/enzimologia , Aspergillus nidulans/genética , Sequência de Bases , Análise Mutacional de DNA , Genes Reporter , Engenharia Genética/métodos , Glucuronidase/genética , Glucuronidase/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/genética , Metarhizium/enzimologia , Biologia Molecular/métodos , Dados de Sequência Molecular , Deleção de Sequência
20.
Cancer Rep (Hoboken) ; 5(9): e1562, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34549901

RESUMO

BACKGROUND: Emerging studies reveals that 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) plays vital oncogenic roles in a broad spectrum of human cancers, but there is no pan-cancer evidence on the relationship between HMGCS1 and various tumor types. AIM: To explore the potential role of HMGCS1 across various tumor types based on big clinical data. METHODS: We conducted a pan-cancer analysis across more than 30 tumor types, based on the most comprehensive database available, including TCGA, GSCA, clinical proteomic tumor analysis consortium, Kaplan-Meier Plotter dataset, GEPIA2, TIMER2, STRING, and GDSC dataset. RESULTS: HMGCS1 was highly expressed and negatively correlated with the prognosis in most cancer types. The infiltration levels of cancer associated fibroblast and CD8+ T-cell were closely associated with HMGCS1 expression. Amplification was the most common genetic alteration of HMGCS1 in different cancers, while the frequency of mutation was low. Besides, ACAT2 and MVD were closely correlated and bind to HMGCS1. Pathway enrichment analysis indicated that HMGCS1 was actively involved in steroid biosynthesis. Moreover, high HMGCS1 expression could reduce the sensitivity to most drugs in the GDSC dataset. CONCLUSIONS: Our study revealed the potential oncogenic role of HMGCS1 in cancers.


Assuntos
Hidroximetilglutaril-CoA Sintase/metabolismo , Proteômica , Acil Coenzima A , Carcinogênese/genética , Linhagem Celular Tumoral , Humanos , Hidroximetilglutaril-CoA Sintase/genética
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