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1.
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
2.
PLoS One ; 18(1): e0277983, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36701319

RESUMO

Fusarium graminearum is the causal agent of Fusarium Head Blight, a serious disease affecting grain crops worldwide. Biological control involves the use of microorganisms to combat plant pathogens such as F. graminearum. Strains of Bacillus velezensis are common biological control candidates for use against F. graminearum and other plant pathogens, as they can secrete antifungal secondary metabolites. Here we study the interaction between B. velezensis E68 and F. graminearum DAOMC 180378 by employing a dual RNA-seq approach to assess the transcriptional changes in both organisms. In dual culture, B. velezensis up-regulated genes related to sporulation and phosphate stress and down-regulated genes related to secondary metabolism, biofilm formation and the tricarboxylic acid cycle. F. graminearum up-regulated genes encoding for killer protein 4-like proteins and genes relating to heavy metal tolerance, and down-regulated genes relating to trichothecene biosynthesis and phenol metabolism. This study provides insight into the molecular mechanisms involved in the interaction between a biocontrol bacterium and a phytopathogenic fungus.


Assuntos
Bacillus , Fusarium , Fusarium/genética , Fusarium/metabolismo , Bacillus/genética , Perfilação da Expressão Gênica , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
3.
Ecotoxicol Environ Saf ; 249: 114379, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508814

RESUMO

High-molecular-weight PAHs (HMW-PAHs) in soil cannot be easily degraded. However, nutrient supplementation could stimulate the growth of exogenously added strains to enhance the degradation of HMW-PAHs in polluted soil. This study evaluated the applicability of Fusarium sp. ZH-H2, a polycyclic aromatic hydrocarbon (PAH)-degrading strain isolated by our research group, for the bioremediation of contaminated soil from the Hebei coal mining area in China. A soil incubation experiment was conducted to investigate the effect of two carbon sources and different carbon, nitrogen, and phosphorus (C:N:P) ratios on the remediation of high-molecular-weight PAHs (HMW-PAHs) in soil by Fusarium sp. ZH-H2, as well as the induction of lignin peroxidase activity. Our findings indicated that the HDF2 treatment (equal parts of humic acid and starch as carbon sources at a 50:1:0.5 C:N:P ratio) enhanced the removal rate of total HMW-PAHs from soil, reaching a maximum removal rate of 37.15 %. The removal rates of Pyr (a 4-ring PAH), BaP (a 5-ring PAH), and BghiP (a 6-ring PAH) were the highest in HDF2 treatment, and the removal rates were 39.51 %, 54.63 %, and 38.60 %, respectively. Compared with the ZH-H2 treatment, different carbon sources and C:N:P ratios significantly induced soil lignin peroxidase activity and the HDF2 treatment also resulted in the highest enzyme activity (up to 34.68 U/L). Furthermore, there was a significant or highly significant linear positive correlation between the removal rate of HMW-PAHs and enzyme activity in all cases. Our findings suggest that the optimal HMW-PAH degradation performance and enhancement of lignin peroxidase activity by ZH-H2 were achieved when both starch and humic acid were used as carbon sources at a C:N:P ratio of 50:1:0.5.


Assuntos
Fusarium , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Solo , Fusarium/metabolismo , Substâncias Húmicas , Hidrocarbonetos Policíclicos Aromáticos/análise , Carbono/metabolismo , Poluentes do Solo/análise , Biodegradação Ambiental , Amido/metabolismo , Microbiologia do Solo
4.
Toxins (Basel) ; 14(12)2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36548718

RESUMO

BACKGROUND: Fumonisin B1 (FB1) is a secondary metabolite produced mainly by Fusarium verticillioides or Fusarium proliferatum. It poses a huge threat to the sustainable animal industry and human health as well via food chains (egg, meat and milk). Although E. coli-expressed nanobodies are documented for diagnostic applications, nanobodies remain elusive as FB1 detoxifiers in feed and food. RESULTS: In the present study, the E. coli-expressed nanobody was assessed to remove FB1 in fresh milk, embryonated eggs and broilers. Firstly, 2 alpacas received intramuscularly FB1-adjuvanted BSA 6 times, and then the variable domain of the heavy-chain antibody (VHH) of fb1 genes were amplified to clone into the pCANTAB 5 E vector in order to generate a VHH-FB1 phage antibody display library, yielding 3.4 × 1010 capacity with 96.7% positivity. Afterwards, 5 anti-FB1 nanobodies were expressed and identified. Furthermore, maximal 43.2% FB1 was removed from milk by 1:2000 concentration of nanobody 5 (Nb5). Furthermore, SPF-embryonated eggs were inoculated into albumens with nanobody-treated FB1. The Nb5 group yielded an 83.3% hatching rate, higher body weight, lower gizzard ulceration and fewer FB1 residuals. In order to warrant the above results, 50 broilers aged 10 days were received orally with 20 ppm of FB1 for 20 days. At the same time, birds were fed orally with 50 µg of Nb5 or bivalent nanobody 11 (BiNb11). Finally, the Nb5 group showed a higher relative body weight gain and lower gastric ulcerations and fewer inflammations in the thymus and bursa. CONCLUSIONS: Based on the above evidence, the Nb5 nanobody may be considered as an additional FB1 detoxifier, contributing to FB1 decontamination.


Assuntos
Fumonisinas , Fusarium , Anticorpos de Domínio Único , Humanos , Animais , Galinhas , Análise Custo-Benefício , Escherichia coli , Leite , Fumonisinas/metabolismo , Peso Corporal , Fusarium/metabolismo
5.
Elife ; 112022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36374166

RESUMO

Pathogens utilize a panoply of effectors to manipulate plant defense. However, despite their importance, relatively little is actually known about regulation of these virulence factors. Here, we show that the effector Fol-Secreted Virulence-related Protein1 (FolSvp1), secreted from fungal pathogen Fusarium oxysporum f. sp. lycopersici (Fol), directly binds and translocates the tomato pathogenesis-related protein1, SlPR1, from the apoplast outside the plasma membrane to the host nucleus via its nuclear localization signal. Relocation of SlPR1 abolishes generation of the defense signaling peptide, CAPE1, from its C-terminus, and as a consequence, facilitates pathogen invasion of plants. The action of FolSvp1 requires covalent modification by acetylation for full virulence in host tomato tissues. The modification is catalyzed by the Fol FolArd1 lysine acetyltransferase prior to secretion. Addition of an acetyl group to one residue, K167, prevents ubiquitination-dependent degradation of FolSvp1 in both Fol and plant cells with different mechanisms, allowing it to function normally in fungal invasion. Either inactivation of FolSvp1 or removal of the acetyl group on K167 leads to impaired pathogenicity of Fol. These findings indicate that acetylation can regulate the stability of effectors of fungal plant pathogens with impact on virulence.


Assuntos
Fusarium , Virulência , Doenças das Plantas/microbiologia , Acetilação , Fusarium/metabolismo , Fatores de Virulência/metabolismo
6.
Toxins (Basel) ; 14(11)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36355997

RESUMO

Nivalenol (NIV) is a trichothecene mycotoxin that is more toxic than deoxynivalenol. It accumulates in grains due to infection with Fusarium species, which are the causative agents of scab or Fusarium head blight. An immunoassay, which is a rapid and easy analytical method, is necessary for monitoring NIV in grains. However, a specific antibody against NIV has not been prepared previously. To establish an immunoassay, we prepared NIV, introduced a linker, and generated antibodies against it. NIV was prepared from a culture of Fusarium kyushuense obtained from pressed barley through chromatographic procedures with synthetic adsorbents and silica gel. NIV was reacted with glutaric anhydride, and the reaction was stopped before mono-hemiglutaryl-NIV was changed to di-hemiglutaryl-NIV. 15-O-Hemiglutaryl-NIV was isolated via preparative HPLC and bound to keyhole limpet hemocyanin (KLH) using the active ester method. Two different monoclonal antibodies were prepared by immunizing mice with the NIV-KLH conjugate. The 50% inhibitory concentration values were 36 and 37 ng/mL. These antibodies also showed high reactivity in a direct competitive enzyme-linked immunosorbent assay and specifically reacted with NIV and 15-acetyl-NIV but not with deoxynivalenol and 4-acetyl-NIV.


Assuntos
Fusarium , Micotoxinas , Tricotecenos , Camundongos , Animais , Micotoxinas/análise , Anticorpos Monoclonais , Tricotecenos/análise , Fusarium/metabolismo
7.
Toxins (Basel) ; 14(11)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36356030

RESUMO

Deoxynivalenol (DON), produced by Fusarium species, is one of the most common trichothecenes detected in cereals pre- and post-harvest, which poses a great threat to the health of livestock and human beings due to its strong toxicity. In this study, we isolated and characterized two DON-degrading bacterial strains, Bacillus sp. HN117 and Bacillus sp. N22. Both strains could degrade DON efficiently in a wide range of temperatures (from 25 °C to 42 °C) and concentrations (from 10 mg/L to 500 mg/L). After optimization of the degradation conditions, 29.0% DON was eliminated by HN117 in 72 h when it was incubated with 1000 mg/L DON; meanwhile, the DON degradation rate of N22 was boosted notably from 7.41% to 21.21% within 120 h at 500 mg/L DON. Degradation products analysis indicated HN117 was able to transform DON into a new isomer M-DOM, the possible structure of which was deduced based on LC-MS and NMR analysis, and N22 could convert DON into potential low-toxic derivatives norDON E and 9-hydroxymethyl DON lactone. These two strains have the potential to be developed as new biodegrading agents to control DON contamination in food and feed industries.


Assuntos
Bacillus , Fusarium , Tricotecenos , Humanos , Bacillus/metabolismo , Tricotecenos/toxicidade , Fusarium/metabolismo , Grão Comestível/química , Contaminação de Alimentos/análise
8.
Protein J ; 41(6): 638-658, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36251227

RESUMO

The resistant and susceptible genotypes of castor were utilized for leaf proteomic study during Fusarium wilt infection. The histopathological study was observed under SEM and it confirmed that the infection of Fusarium oxysporum f. sp. ricini was higher in the root of susceptible JI-35, while incompatible interaction is observed in resistant SKI-215 genotype. The acidic and neutral proteins were maximally up-expressed with 2 to 171 kDa in treated resistant and 2 to 150 kDa in treated susceptible interactions. In resistant genotype, the leaf proteins were recognized with 3.0- and 5.8-fold higher at infection stage and post-infection stage, respectively, as compared to susceptible genotype. The highly up expressions of leaf acidic (4.76 pI) and basic (8.77 pI) proteins were found with 224.94- and 61.68-fold change, respectively during the post-infection stage in treated resistance compared to its control. The protein spots at 4.76 pI and 8.77 pI were characterized with nanoLC-MS Triple TOF and were recognized as signalling molecules small GTP binding protein (23 kDa) and actin (8 kDa), respectively, on the basis of mass spectrometry and peptide sequences. However, basic and neutral proteins were up regulated as 30.11- and 20.30-fold changes in treated susceptible compared to its control. These proteins were identified as HSP90 (10 kDa) and LEA (27 kDa) proteins. The 148 kDa protein is recognized as histidine kinase in incompatible resistant interaction compared to compatible susceptible (serine threonine protein kinase, 65 kDa) as common acidic protein at 3.80 pI during infection stage. Some acidic proteins were maximally up-regulated in the leaf of resistant castor genotype and played a significant role in defense response.


Assuntos
Fusarium , Fusarium/metabolismo , Proteômica , Doenças das Plantas/genética , Ricinus , Genótipo , Folhas de Planta/genética , Espectrometria de Massas
9.
Environ Microbiol ; 24(11): 5392-5407, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36200537

RESUMO

Fusarium graminearum is an important wheat pathogen and a producer of deoxynivalenol (DON). Biosynthesis of DON is suppressed by ammonium and induced by arginine and polyamines. To better understand ammonium repression of DON biosynthesis, in this study, we functionally characterized three ammonium permease (MEP) genes in F. graminearum. All the mep deletion mutants were normal in growth on V8 agar. Whereas deletion of MEP1 had no detectable phenotypes, the mep2 and mep3 mutants had defects in hyphal growth under ammonium limiting conditions and infection of wheat heads, with the latter having less severe defects. Deletion of MEP2 but not MEP3 affected nitrogen repression of DON biosynthesis and genes involved in nitrate metabolism. The mep2 mep3 double mutant had more severe defects in nitrogen repression than the mep2 mutant and was defective in ascospore releasing. Mutant alleles of MEP2 with truncated C-terminal cytoplasmic tail (CT) failed to complement the mep2 mutant. Expression of a dominant active allele of RAS2 partially rescued the defects of mep2 in nitrogen repression. Taken together, these results suggest that Mep2 acts as the major sensor of ammonium availability in F. graminearum and its CT region functions in nitrogen repression via RAS2 and downstream signalling pathways.


Assuntos
Compostos de Amônio , Fusarium , Proteínas de Membrana Transportadoras/genética , Compostos de Amônio/metabolismo , Nitrogênio/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/genética , Fusarium/metabolismo , Regulação Fúngica da Expressão Gênica , Doenças das Plantas
10.
Environ Microbiol ; 24(11): 5362-5377, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36111363

RESUMO

Very long-chain fatty acids (VLCFAs), the precursors for the synthesis of sphingolipids (SLs), play pivotal roles in the development and stress response in eukaryotes. In Saccharomyces cerevisiae, VLCFAs are synthesized in the endoplasmic reticulum (ER) through a four-step elongation cycle. However, the functions of VLCFA elongases in phytopathogenic fungi remain largely unexplored. Here, we identified a single copy of the VLCFA elongase gene FgELO2 in Fusarium graminearum that causes Fusarium head blight worldwide. FgElo2 localized to ER membrane, and deletion mutant of FgELO2 exhibited serious defects in vegetative growth and conidiation. Importantly, ΔFgElo2 led to ergosterol content reduction and disrupted the ER-localization of 14-α-demethylase FgCyp51s, indicating that the scarce of SLs reduced ergosterol, which ultimately elevated the sensitivity of ΔFgElo2 to tebuconazole. Fluorescent microscopic examination suggested that FgElo2 was degraded upon cell membrane stress. ΔFgElo2 showed decreased phosphorylation of high osmolarity glycerol (HOG) pathway and subsequently exhibited remarkable sensitivity to osmotic stress. In addition, fungal virulence was dramatically reduced in ΔFgElo2 via inhibiting deoxynivalenol production and formation of infection structures. Together, this study demonstrates that the VLCFA elongase FgElo2 modulates fungal development, tebuconazole sensitivity, stress responses and virulence, which may advance our understanding of pathogen-host interactions mediated by VLCFAs.


Assuntos
Fusarium , Fusarium/metabolismo , Virulência/genética , Elongases de Ácidos Graxos , Proteínas Fúngicas/genética , Ergosterol/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Esporos Fúngicos/metabolismo , Doenças das Plantas/microbiologia
11.
Appl Microbiol Biotechnol ; 106(19-20): 6595-6609, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36121485

RESUMO

Fusarium verticillioides, a well-known fungal pathogen that causes severe disease in maize and contaminates the grains with fumonisin B1 (FB1) mycotoxin, affects the yield and quality of maize worldwide. The intrinsic roles of peroxisome targeting signal (PTS)-containing proteins in phytopathogens remain elusive. We therefore explored the regulatory role and other biological functions of the components of PTS2 receptor complex, FvPex7 and FvPex20, in F. verticillioides. We found that FvPex7 directly interacts with the carboxyl terminus of FvPex20 in F. verticillioides. PTS2-containing proteins are recognized and bound by the FvPex7 receptor or the FvPex7-Pex20 receptor complex in the cytoplasm, but the peroxisome localization of the PTS2-Pex7-Pex20 complex is only determined by Pex20 in F. verticillioides. However, we observed that some putative PTS2 proteins that interact with Pex7 are not transported into the peroxisomes, but a PTS1 protein that interacts with Pex5 was detected in the peroxisomes. Furthermore, ΔFvpex7pex20 as well as ΔFvpex7pex5 double mutants exhibited reduced pathogenicity and FB1 biosynthesis, along with defects in conidiation. The PTS2 receptor complex mutants (ΔFvpex7pex20) grew slowly on minimal media and showed reduced sensitivity to cell wall and cell membrane stress-inducing agents compared to the wild type. Taken together, we conclude that the PTS2 receptor complex mediates peroxisome matrix proteins import and contributes to pathogenicity and FB1 biosynthesis in F. verticillioides. KEY POINTS: • FvPex7 directly interacts with FvPex20 in F. verticillioides. • vThe PTS2 receptor complex is essential for the importation of PTS2-containing matrix protein into peroxisomes in F. verticillioides. • Fvpex7/pex20 is involved in pathogenicity and FB1 biosynthesis in F. verticillioides.


Assuntos
Fumonisinas , Fusarium , Fumonisinas/metabolismo , Fusarium/genética , Fusarium/metabolismo , Receptor 2 de Sinal de Orientação para Peroxissomos/metabolismo , Sinais de Orientação para Peroxissomos , Receptor 1 de Sinal de Orientação para Peroxissomos/genética , Receptor 1 de Sinal de Orientação para Peroxissomos/metabolismo , Peroxissomos/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Virulência
12.
Chem Biodivers ; 19(11): e202200687, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36149759

RESUMO

Antimicrobial compounds produced by bacteria have been increasingly acknowledged as an important resource for the control of phytopathogens. We used a bioassay-guided fractionation approach to identify antifungal metabolites produced by two avocado rhizobacteria (INECOL-4742 and INECOL-5927), both members of the Bacillus subtilis/B. amyloliquefaciens species complex, against Fusarium solani and F. kuroshium, causal agent of Fusarium dieback in avocado and other hosts. The butanol (BuOH) organic extract from INECOL-4742 (B1-Bu) exhibited the highest percentage of inhibition (PI) against F. solani (78.76 %), also inhibiting F. kuroshium by up to 44.30 %. Primary fractions, Bu-F3, Bu-F12 and Bu-F15, obtained by silica gel open column chromatography, exhibited the highest PI against F. solani (28.57 % to 33.50 %) and F. kuroshium (38.78 % to 45.00 %). The presence of cyclic lipopeptides from the iturin, surfactin and fengycin families in B1-Bu extracts and primary fractions was determined by UPLC-ESI-HRMS. The Confocal Laser Microscopy analysis revealed deformations in the hyphae of F. kuroshium exposed to extracts, primary fractions and C-13 surfactin chemical standard. These results emphasize the potential of natural products from Bacillus for the control of the emerging phytopathogenic fungus F. kuroshium.


Assuntos
Bacillus , Produtos Biológicos , Fusarium , Persea , Humanos , Fusarium/metabolismo , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Lipopeptídeos/farmacologia , Lipopeptídeos/análise , Lipopeptídeos/metabolismo , Produtos Biológicos/metabolismo , Bioensaio , Doenças das Plantas/microbiologia
13.
Int J Mol Sci ; 23(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36142806

RESUMO

Mycotoxin contamination of maize kernels by fungal pathogens like Fusarium verticillioides and Aspergillus flavus is a chronic global challenge impacting food and feed security, health, and trade. Maize lipoxygenase genes (ZmLOXs) synthetize oxylipins that play defense roles and govern host-fungal interactions. The current study investigated the involvement of ZmLOXs in maize resistance against these two fungi. A considerable intraspecific genetic and transcript variability of the ZmLOX family was highlighted by in silico analysis comparing publicly available maize pan-genomes and pan-transcriptomes, respectively. Then, phenotyping and expression analysis of ZmLOX genes along with key genes involved in oxylipin biosynthesis were carried out in a maize mutant carrying a Mu transposon insertion in the ZmLOX4 gene (named UFMulox4) together with Tzi18, Mo17, and W22 inbred lines at 3- and 7-days post-inoculation with F. verticillioides and A. flavus. Tzi18 showed the highest resistance to the pathogens coupled with the lowest mycotoxin accumulation, while UFMulox4 was highly susceptible to both pathogens with the most elevated mycotoxin content. F. verticillioides inoculation determined a stronger induction of ZmLOXs and maize allene oxide synthase genes as compared to A. flavus. Additionally, oxylipin analysis revealed prevalent linoleic (18:2) peroxidation by 9-LOXs, the accumulation of 10-oxo-11-phytoenoic acid (10-OPEA), and triglyceride peroxidation only in F. verticillioides inoculated kernels of resistant genotypes.


Assuntos
Fumonisinas , Fusarium , Micotoxinas , Aspergillus flavus/genética , Aspergillus flavus/metabolismo , Fusarium/metabolismo , Lipoxigenase/genética , Lipoxigenase/metabolismo , Micotoxinas/metabolismo , Oxilipinas/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triglicerídeos/metabolismo , Zea mays/metabolismo
14.
Plant Physiol Biochem ; 190: 11-23, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36087542

RESUMO

Underground infection of Fusarium oxysporum resulted in great yield losses in chrysanthemum (Chrysanthemum morifolium Ramat.) industry. However, the effect of F. oxysporum root disease on the terpenes production in above- and below-ground parts of plant is completely unexplored. The aim of this study was to investigate the systematic impact of Fusarium infection underground on the terpene production in aboveground parts of chrysanthemum. Terpene production in above- and below-ground parts was profiled in a time series of post-inoculation by GC-MS. Total terpenes were significantly induced from roots and leaves of Fusarium-infected versus healthy plants. These terpenes included monoterpenes, sesquiterpenes and diterpenes, in which sesquiterpenes were primarily induced in roots and leaves, while monoterpenes were produced only in leaves. Through transcriptome analysis, 8 differentially expressed terpene synthase genes (TPSs) were screened out. The relative expression levels of 8 TPS genes at different developmental stage and tissues indicated the spatial delay of the TPS genes in leaves. The induced terpenes from roots and leaves showed consistency with the expression pattern of TPS genes. The biochemical function of Cm-j-TPS1/2/7 were verified by enzymatic assay. Additionally, it's found that the content of salicylic acid (SA) in root and leaf significantly increased by F. oxysporum infection, suggesting a role of the SA signaling pathway in defense. Together, these results reveal the defense response of above- and below-ground parts of plants to root fungal attack and provide a theoretical basis for the effective prediction and control of F. oxysporum infection in chrysanthemum.


Assuntos
Chrysanthemum , Fusariose , Fusarium , Sesquiterpenos , Chrysanthemum/metabolismo , Fusarium/metabolismo , Monoterpenos , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Terpenos
15.
Sci Rep ; 12(1): 14737, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042239

RESUMO

Deoxynivalenol (DON) is a mycotoxin, produced by filamentous fungi such as Fusarium graminearum, that causes significant yield losses of cereal grain crops worldwide. One of the most promising methods to detoxify this mycotoxin involves its enzymatic epimerization to 3-epi-DON. DepB plays a critical role in this process by reducing 3-keto-DON, an intermediate in the epimerization process, to 3-epi-DON. DepBRleg from Rhizobium leguminosarum is a member of the new aldo-keto reductase family, AKR18, and it has the unusual ability to utilize both NADH and NADPH as coenzymes, albeit with a 40-fold higher catalytic efficiency with NADPH compared to NADH. Structural analysis of DepBRleg revealed the putative roles of Lys-217, Arg-290, and Gln-294 in NADPH specificity. Replacement of these residues by site-specific mutagenesis to negatively charged amino acids compromised NADPH binding with minimal effects on NADH binding. The substrate-binding site of DepBRleg is larger than its closest structural homolog, AKR6A2, likely contributing to its ability to utilize a wide range of aldehydes and ketones, including the mycotoxin, patulin, as substrates. The structure of DepBRleg also suggests that 3-keto-DON can adopt two binding modes to facilitate 4-pro-R hydride transfer to either the re- or si-face of the C3 ketone providing a possible explanation for the enzyme's ability to convert 3-keto-DON to 3-epi-DON and DON in diastereomeric ratios of 67.2% and 32.8% respectively.


Assuntos
Fusarium , Micotoxinas , Aldo-Ceto Redutases/genética , Aldo-Ceto Redutases/metabolismo , Fusarium/metabolismo , Micotoxinas/metabolismo , NAD/metabolismo , NADP/metabolismo , Tricotecenos
16.
Toxins (Basel) ; 14(8)2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-36006184

RESUMO

Maize is considered one of the most susceptible crops to mycotoxin-producing fungi throughout the world, mainly belonging to the Fusarium spp. and Aspergillus spp. Maize is mainly used as animal feeds in Italy, as well as for human consumption, being essential for all the protected designation of origin (DOP) products. Our study investigated the occurrence of regulated mycotoxins in 3769 maize grain samples collected from 88 storage centers by the National Monitoring Network over an 11-year period (2011-2021). Moreover, an in-depth survey over a 4-year period, characterized by extremely different meteorological conditions, was conducted to investigate the co-occurrence of regulated, masked, and emerging mycotoxins. The survey confirmed that Fusarium spp. was the most frequent fungi and fumonisins were the main mycotoxins that were constantly detected in the different years and areas. Moreover, the areas characterized by high fumonisin levels were also the most prone to contamination by emerging mycotoxins produced by the same Fusarium species of the Liseola section. On the other hand, as a result of climatic changes, maize grains have also been affected by the increased frequency of aflatoxin accumulation. Deoxynivalenol, zearalenone, and other emerging mycotoxins produced by the same Fusarium species as the Discolor section occurred more abundantly in some areas in Northern Italy and in years characterized by predisposing meteorological conditions.


Assuntos
Fumonisinas , Fusarium , Mariposas , Micotoxinas , Animais , Contaminação de Alimentos/análise , Fumonisinas/análise , Fusarium/metabolismo , Humanos , Micotoxinas/análise , Zea mays/microbiologia
17.
Toxins (Basel) ; 14(8)2022 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-36006189

RESUMO

Mycotoxins are secondary metabolites produced by fungi that infect a wide range of foods worldwide. Nivalenol (NIV), a type B trichothecene produced by numerous Fusarium species, has the ability to infect a variety of foods both in the field and during post-harvest handling and management. NIV is frequently found in cereal and cereal-based goods, and its strong cytotoxicity poses major concerns for both human and animal health. To address these issues, this review briefly overviews the sources, occurrence, chemistry and biosynthesis of NIV. Additionally, a brief overview of several sophisticated detection and management techniques is included, along with the implications of processing and environmental factors on the formation of NIV. This review's main goal is to offer trustworthy and current information on NIV as a mycotoxin concern in foods, with potential mitigation measures to assure food safety and security.


Assuntos
Fusarium , Micotoxinas , Animais , Grão Comestível/química , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Fusarium/metabolismo , Humanos , Micotoxinas/análise , Tricotecenos
18.
Toxins (Basel) ; 14(8)2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-36006206

RESUMO

Fumonisin mycotoxins are a family of secondary metabolites produced by Fusarium verticillioides and related species, as well as some strains of Aspergillus niger. Fumonisin contamination of maize is a concern when grown under hot, dry conditions. When present above regulatory levels, there can be effects on animal health. New tools to reduce the toxicity of maize and maize products with high concentrations of fumonisin are needed. Recently, we reported an amine oxidase (AnFAO) from a fumonisin-producing Aspergillus niger strain capable of oxidatively deaminating intact fumonisins. In this study, AnFAO was used to reduce intact fumonisin concentrations in milled maize flour, whole kernel maize inoculated with fumonisin-producing Fusarium verticillioides, and dried distillers' grains with solubles (DDGS). The data showed that milled maize flour incubated with 1 µM AnFAO for 1 h resulted in complete deamination of FB1 and FB2. A greater than 90% reduction in FB1-3 concentrations was observed following a simple washing procedure of whole kernel maize in the presence of 1 µM AnFAO for 1 h. Similarly, a ≥86% reduction in FB1-3 concentrations was observed in DDGS after 4 h incubation with 1 µM AnFAO. Finally, we engineered the methylotrophic yeast Pichia pastoris to produce functional AnFAO in both a secreted and intracellular form. These results support the further development and application of AnFAO as a promising tool to remediate fumonisin-contaminated maize and maize products.


Assuntos
Fumonisinas , Fusarium , Aminas , Animais , Aspergillus , Aspergillus niger/metabolismo , Fumonisinas/toxicidade , Fusarium/metabolismo , Oxirredutases/metabolismo , Zea mays/metabolismo
19.
Toxins (Basel) ; 14(8)2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-36006230

RESUMO

Fusarium proliferatum is the primary cause of spikelet rot disease in rice (Oryza sativa L.) in China. The pathogen not only infects a wide range of cereals, causing severe yield losses but also contaminates grains by producing various mycotoxins that are hazardous to humans and animals. Here, we firstly reported the whole-genome sequence of F. proliferatum strain Fp9 isolated from the rice spikelet. The genome was approximately 43.9 Mb with an average GC content of 48.28%, and it was assembled into 12 scaffolds with an N50 length of 4,402,342 bp. There is a close phylogenetic relationship between F. proliferatum and Fusarium fujikuroi, the causal agent of the bakanae disease of rice. The expansion of genes encoding cell wall-degrading enzymes and major facilitator superfamily (MFS) transporters was observed in F. proliferatum relative to other fungi with different nutritional lifestyles. Species-specific genes responsible for mycotoxins biosynthesis were identified among F. proliferatum and other Fusarium species. The expanded and unique genes were supposed to promote F. proliferatum adaptation and the rapid response to the host's infection. The high-quality genome of F. proliferatum strain Fp9 provides a valuable resource for deciphering the mechanisms of pathogenicity and secondary metabolism, and therefore shed light on development of the disease management strategies and detoxification of mycotoxins contamination for spikelet rot disease in rice.


Assuntos
Fumonisinas , Fusarium , Micotoxinas , Oryza , Fumonisinas/metabolismo , Fusarium/metabolismo , Humanos , Micotoxinas/genética , Micotoxinas/metabolismo , Oryza/microbiologia , Filogenia , Metabolismo Secundário , Virulência
20.
Biotechnol Lett ; 44(10): 1111-1126, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36006577

RESUMO

Mycotoxin contamination of food and feed is a serious food safety issue and causes acute and chronic diseases in humans and livestock. Climatic and agronomic changes helps in the proliferation of fungal growth and mycotoxin production in food commodities. Mycotoxin contamination has attracted global attention due to its wide range of toxicity to humans and animals. However, physical and chemical management approaches in practice are unsafe for well-being due to their health-hazardous nature. Various antibiotics and preservatives are in use to reduce the microbial load and improve the shelf life of food products. In addition, the use of antibiotic growth promotors in livestock production may increase the risk of antimicrobial resistance, which is a global health concern. Due to their many uses, probiotics are helpful microbes that have a significant impact on food and nutrition. Furthermore, the probiotic potential of lactic acid bacteria (LAB) is employed in various food and feed preparations to neutralize mycotoxins, antimicrobial activities, balance the gut microbiome, and various immunomodulatory activities in both humans and livestock. In addition, LAB produces various antimicrobials, flavouring agents, peptides, and proteins linked to various food and health care applications. The LAB-based processes for mycotoxin management are more effective, eco-friendly, and low-cost than physical and chemical approaches. The toxicity, novel preventive measures, binding nature, and molecular mechanisms of mycotoxins' detoxification using LAB have been highlighted in this review.


Assuntos
Fusarium , Lactobacillales , Micotoxinas , Animais , Antibacterianos/metabolismo , Aromatizantes/metabolismo , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Fusarium/metabolismo , Humanos , Lactobacillales/metabolismo , Micotoxinas/análise , Micotoxinas/metabolismo , Micotoxinas/toxicidade
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