Fusarium Subglutinans Research Articles

Organic vs conventional farming: Differences in infection by mycotoxin-producing fungi on maize and wheat in Northern and Central Italy

This study aimed to monitor the main toxigenic fungi in neighbouring organic and conventional maize and wheat fields in Italy in 2010 and 2011. The Fusarium species mainly isolated were: Fusarium poae, sometimes predominant on Fusarium graminearum in wheat, and Fusarium verticillioides competing with Fusarium proliferatum and Fusarium subglutinans in maize. The incidence of Fusarium spp. was similar for both conventional (6%) and organic (4%) wheat, but it was influenced by weather conditions. 2010 was the most favourable for Fusarium species, with 10 times the incidence of 2011. Fusarium infection was significantly different between farming systems in maize (20% vs 35% in conventional and organic, respectively), while in 2010 the incidence was significantly higher than in 2011 (43% vs 25%). Aspergillus and Penicillium incidence was not linked to the farming system but to weather conditions, with moderately higher incidence in 2010.

Fusarium temperatum and Fusarium subglutinans isolated from maize in Argentina

Fusarium temperatum and Fusarium subglutinans isolated from the Northwest region (NOA region) of Argentina were characterized using a polyphasic approach based on morphological, biological and molecular markers. Some interfertility between the species was observed. The phylogenetic analysis showed that the two species represented two clades strongly supported by bootstrap values. The toxigenic profile of the strains was also determined. F. temperatum strains were fusaproliferin and beauvericin producers, and only some strains were fumonisin B1 producers. All F. subglutinans strains produced fusaproliferin but none produced beauvericin, indicating a potential toxicological risk from maize harvested in the NOA region of Argentina. This study provides new information about F. temperatum isolated from maize in Argentina.

Characterization of the Maize Stalk Rot Pathogens Fusarium subglutinans and F. temperatum and the Effect of Fungicides on Their Mycelial Growth and Colony Formation.

Maize is a socioeconomically important crop in many countries. Recently, a high incidence of stalk rot disease has been reported in several maize fields in Gangwon province. In this report, we show that maize stalk rot is associated with the fungal pathogens Fusarium subglutinans and F. temperatum. Since no fungicides are available to control these pathogens on maize plants, we selected six fungicides (tebuconazole, difenoconazole, fluquinconazole, azoxystrobin, prochloraz and kresoxim-methyl) and examined their effectiveness against the two pathogens. The in vitro antifungal effects of the six fungicides on mycelial growth and colony formation were investigated. Based on the inhibition of mycelial growth, the most toxic fungicide was tebuconazole with 50% effective concentrations (EC50) of <0.1 μg/ml and EC90 values of 0.9 μg/ml for both pathogens, while the least toxic fungicide was azoxystrobin with EC50 values of 0.7 and 0.5 μg/ml for F. subglutinans and F. temperatum, respectively, and EC90 values of >3,000 μg/ml for both pathogens. Based on the inhibition of colony formation by the two pathogens, kresoxim-methyl was the most toxic fungicide with complete inhibition of colony formation at concentrations of 0.1 and 0.01 μg/ml for F. subglutinans and F. temperatum, respectively, whereas azoxystrobin was the least toxic fungicide with complete inhibition of colony formation at concentrations >3,000 μg/ml for both pathogens.

Microbial community diversity associated with Sarcotragus sp. and Petrosia ficiformis from the Aegean Sea based on 16S rDNA-DGGE fingerprinting

Marine sponges are prolific sources for new bioactive compounds and they may contain microorganisms that can comprise up to 40% of the total sponge biomass. Therefore, it is important to understand the function and the specific interactions of sponge-associated microorganisms. In this study, we assessed the composition of predominant bacterial and fungal communities using DGGE fingerprinting of Sarcotragus sp. and Petrosia ficiformis collected from the Aegean Sea. Total community DNA extracted with the indirect DNA isolation method by using collagenase followed by 16S rDNA and ITS amplification of 16S rDNA and ITS amplicons were subjected to DGGE profiling. A total of 8 and 21 individual DGGE bands from 16S rDNA-V3 and ITS1 fragments were sequenced, respectively, and matched to corresponding bacteria and fungi in the GenBank database. Methylobacterium sp. and Chalastospora gossypii from Sarcotragus sp. and Gibberella intermedia and Fusarium subglutinans from Petrosia ficiformis are reported for the first time from marine sponges. Associated microorganisms of Sarcotragus sp. and Petrosia ficiformis are considered as host-specific, as tested sponges from the same geographical location showed different dominant bacterial and fungal diversities.

PENGENDALIAN HAYATI PENYEBAB PENYAKIT REBAH SEMAI Fusarium subglutinans DENGAN Trichoderma harzianum

The mortality of pine seedling in nursery was caused by damping off. Damping off disease is caused by soil borne pathogenic fungus Fusarium subglutinans. To get an effective method in controlling the diseases, is important to understand the effectiveness of biocontrol agent Trichoderma harzianum. The purpose of this research was to comprehend the inhibition mechanism of T. harzianum against F. subglutinans and its effectiveness. The research methods include (1) in vitro application of T. harzianum with Green Fluorescent Protein [GFP] using dual culture method, and (2) in planta application by inoculating T. harzianum with GFP four days before F. subglutinans inoculation, inoculating T. harzianum and F. subglutinans at the same time, and inoculating of T. harzianum four days after F. subglutinans inoculation. The results of this research showed that Trichoderma harzianum is effective to inhibit the growth of F. subglutinans in planta. The mechanism of T.harzianum to inhibit the growh of F.subglutinans is by nutrient competition.

PENGENDALIAN HAYATI PENYEBAB PENYAKIT REBAH SEMAI Fusarium subglutinans DENGAN Trichoderma harzianum

The mortality of pine seedling in nursery was caused by damping off. Damping off disease is caused by soil borne pathogenic fungus Fusarium subglutinans. To get an effective method in controlling the diseases, is important to understand the effectiveness of biocontrol agent Trichoderma harzianum. The purpose of this research was to comprehend the inhibition mechanism of T. harzianum against F. subglutinans and its effectiveness. The research methods include (1) in vitro application of T. harzianum with Green Fluorescent Protein [GFP] using dual culture method, and (2) in planta application by inoculating T. harzianum with GFP four days before F. subglutinans inoculation, inoculating T. harzianum and F. subglutinans at the same time, and inoculating of T. harzianum four days after F. subglutinans inoculation. The results of this research showed that Trichoderma harzianum is effective to inhibit the growth of F. subglutinans in planta. The mechanism of T.harzianum to inhibit the growh of F.subglutinans is by nutrient competition.

Identification of Fusarium subglutinans, the Casual Pathogen of Corn Stalk Rot in Korea and Investigation of Effectiveness of Fungicides Against the Pathogen

Identification of Fusarium subglutinans, the Casual Pathogen of Corn Stalk Rot in Korea and Investigation of Effectiveness of Fungicides Against the Pathogen

THE INFECTION PROCESS OF Fusarium subglutinans IN Pinus merkusii SEEDLINGS

Pinus merkusii or tusam is an original Indonesian plant and it is naturally distributed in Aceh and North Sumatra. Damping-off disease is the main problem in its nurseries. Fusarium subglutinans is one of the leading causes of damping-off disease. The knowledge of fungal infections process of tusam seedlings is essential to control damping- off disease effectively.The aim of this research is to understand (1) infection process of F. subglutinans in tusam seedlings and the defence response of seedlings against the infection of F. subglutinans . The methods used in this research were (1) identification of fungal pathogens that causing the disease, (2) pathogenicity test of F. subglutinans , (3) detection the accumulation of lignin, accumulation of callose and hypersensitive reactions by staining of seedling tissue using phloroglucinol, aniline blue and lactophenol trypan blue.The results of this study revealed that spores germination occurred in two days after inoculation. Direct penetration through cell wall and stomata was observed on the third day after inoculation. There was hypersensitive reaction in stomata. Accumulation of callose and lignin appeared on the third day after inoculation. However, defence response of seedlings was not effective, as F. subglutinans is a necrotroph fungus. Keywords: damping-off, Fusarium subglutinans, Pinus merkusii, tusam

Infection of Corn Ears by Fusarium spp. Induces the Emission of Volatile Sesquiterpenes

Infection of corn (Zea mays L.) ears with fungal pathogens of the Fusarium genus might result in yield losses and in the accumulation of mycotoxins. The aim of this study was to investigate whether volatile profiles could be used to identify Fusarium-infected corn ears. The volatiles released by corn ears infected by Fusarium graminearum, Fusarium verticillioides, and Fusarium subglutinans were studied. Volatile emission was recorded at 24 days postinoculation (dpi) and in a time series (from 4 to 24 dpi). Twenty-two volatiles were differentially emitted from Fusarium-infected versus healthy corn ears. These included C6-C8 compounds and sesquiterpenoids. All volatiles indicative of Fusarium infection were detectable as early as 4-8 dpi and continued to be produced to the final sampling time (early milk maturity stage). The induced emission of β-macrocarpene and β-bisabolene correlated with an increased transcript accumulation of corn terpene synthase 6/11 (tps6/11). Additionally, the modification of volatile profiles after Fusarium infection was accompanied by the induction of plant defense compounds such as zealexins and oxylipins. Together, these results reveal a broad metabolic response of the plant to pathogen attack. Volatile biomarkers of Fusarium infection are promising indicators for the early detection of fungal infection before disease symptoms become visible.

Biological evaluation of subglutinol a as a novel immunosuppressive agent for inflammation intervention.

Subglutinol A (1) is an immunosuppressive natural product isolated from Fusarium subglutinans, an endophytic fungus from the vine Tripterygium wilfordii. We show that 1 exerts multimodal immune-suppressive effects on activated T cells in vitro: subglutinol A (1) effectively blocks T cell proliferation and survival while profoundly inhibiting pro-inflammatory IFNγ and IL-17 production by fully differentiated effector Th1 and Th17 cells. Our data further reveal that 1 may exert its anti-inflammatory effects by exacerbating mitochondrial damage in T cells. Additionally, we demonstrate that 1 significantly reduces lymphocytic infiltration into the footpad and ameliorates footpad swelling in the mouse model of Th1-driven delayed-type hypersensitivity. These results suggest the potential of 1 as a novel therapeutic for inflammatory diseases.

Screening biological activities of soil-borne Streptomyces sp. against several phytopathogenic fungi

About 70 Streptomyces species, isolated from soils of greenhouses and citrus orchards were evaluated for their antagonistic activity against Verticillium dahliae, Fusarium subglutinans, Fusarium sambucinum, Phoma glomerata and Nattrassia mangiferae. Preliminary screening for antimicrobial activity was determined by dual culture method. The soils of Kerman are rich sources of micro-organisms with potent biological activities, and screening programmes are to be conducted to reveal the presence of active Actinomycetes isolates against phytopathogenic fungi.

Investigations on Fusarium spp. and their mycotoxins causing Fusarium ear rot of maize in Kosovo

After wheat, maize (Zea mays L.) is the second most important cereal crop in Kosovo and a major component of animal feed. The purpose of this study was to analyse the incidence and identity of the Fusarium species isolated from naturally infected maize kernels in Kosovo in 2009 and 2010, as well as the mycotoxin contamination. The disease incidence of Fusarium ear rot (from 0.7% to 40% diseased ears) on maize in Kosovo is high. The most frequently Fusarium spp. identified on maize kernels were Fusarium subglutinans, F. verticillioides/F. proliferatum and F. graminearum. Maize kernel samples were analysed by LC-MS/MS and found to be contaminated with deoxynivalenol (DON), DON-3-glucoside, 3-acetyl-DON, 15-acetyl-DON, zearalenone, zearalenone-14-sulphate, moniliformin, fumonisin B1 and fumonisin B2. This is the first report on the incidence and identification of Fusarium species isolated from naturally infected maize as well as the mycotoxin contamination in Kosovo.

Isolation and investigation of extracellular metabolites of Streptomyces sp. for biological control of Fusarium subglutinans, the causal agent of wilting cucumber greenhouse

Seventy Streptomyces isolates were obtained from the Rhizosphere and soil of greenhouse and their antagonistic activities against Fusarium subglutinans in dual culture test was studied. Two isolates had antagonistic activities against F. subglutinans. These isolates were tested for determining the antagonistic mechanism effects of extracellular metabolites (such as amylase, protease and lipase). The results exhibited that two isolates of Streptomyces sp. C-11 and C-26 have the ability to produce enzymes, such as amylase, protease and lipase, in vitro.

Structural variation and dynamics of the nuclear ribosomal intergenic spacer region in key members of theGibberella fujikuroispecies complex

The intergenic spacer (IGS) region of the ribosomal DNA was cloned and sequenced in eight species within the Gibberella fujikuroi species complex with anamorphs in the genus Fusarium, a group that includes the most relevant toxigenic species. DNA sequence analyses revealed two categories of repeated elements: long repeats and short repeats of 125 and 8 bp, respectively. Long repeats were present in two copies and were conserved in all the species analyzed, whereas different numbers of short repeat elements were observed, leading to species-specific IGS sequences with different length. In Fusarium subglutinans and Fusarium nygamai, these differences seemed to be the result of duplication and deletion events. Here, we propose a model based on unequal crossing over that can explain these processes. The partial IGS sequence of 22 Fusarium proliferatum isolates was also obtained to study variation at the intraspecific level. The results revealed no differences in terms of number or pattern of repeated elements and detected frequent gene conversion events. These results suggest that the homogenization observed at the intraspecific level might not be achieved primarily by unequal crossing-over events but rather by processes associated with recombination such as gene conversion events.

Epidemic significance of planting time and hybrid on Fusarium infection of maize in two agroecological zones of Zambia

Most hybrid maize samples from three years of field experiments in Zambia contained Fusarium spp., but there were differences between hybrid susceptibility in two agroecological zones. Mean annual kernel infection ranged from 14 to 63% in the medium rainfall zone (MRZ). In the high rainfall zone (HRZ), the highest mean annual infection recorded was 18%. A Partial Least Square (PLS) analysis showed negative relationship between Fusarium kernel infection and rainy days before midsilk and positive relationship between Fusarium kernel infection and number of dry weeks between planting and midsilk. Fusarium verticillioides was most frequently isolated, and the highest incidences and levels were found in the MRZ. Other species detected included: Fusarium subglutinans, Fusarium oxysporum, Fusarium graminearum, Fusarium compactum, Fusarium equiseti, Fusarium proliferatum, Fusarium nygamai, Fusarium semitectum and Fusarium anthophilum. This is the first report of the presence of F. compactum, F. nygamai and F. anthophilum in maize in Zambia.

Transmission ratio distortion in an interspecific cross between Fusarium circinatum and Fusarium subglutinans

Previously, an interspecific cross between Fusarium circinatum and Fusarium subglutinans was used to generate a genetic linkage map. A ca. 55 % of genotyped markers displayed transmission ratio distortion (TRD) that demonstrated a genome-wide distribution. The working hypothesis for this study was that TRD would be non-randomly distributed throughout the genetic linkage map. This would indicate the presence of distorting loci. Using a genome-wide threshold of α = 0.01, 79 markers displaying TRD were distributed on all 12 linkage groups (LGs). Eleven putative transmission ratio distortion loci (TRDLs), spanning eight LGs, were identified in regions containing three or more adjacent markers displaying distortion. No epistatic interactions were observed between these TRDLs. Thus, it is uncertain whether the genome-wide TRD was due to linkage between markers and genomic regions causing distortion. The parental origins of markers followed a non-random distribution throughout the linkage map, with LGs containing stretches of markers originating from only one parent. Thus, due to the nature of the interspecific cross, the current hypothesis to explain these observations is that the observed genome-wide segregation was caused by the high level of genomic divergence between the parental isolates. Therefore, homologous chromosomes do not align properly during meiosis, resulting in aberrant transmission of markers. This also explains previous observations of the preferential transmission of F. subglutinans alleles to the F1 progeny.

Fusarium subglutinans: A new eumycetoma agent

Eumycetoma is a chronic subcutaneous mycosis mainly caused by Madurella spp. Fusarium opportunistic infections in humans are often caused by Fusarium solani and Fusarium oxysporum. We report a case of eumycetoma by F. subglutinans, diagnosed by clinical aspect and culture, and confirmed by PCR sequencing. The patient was successfully treated with oral itraconazole. To our knowledge, this is the second report of human infection and the first case of mycetoma by Fusarium subglutinans.

Production of enniatins A, A1, B, B1, B4, J1 by Fusarium tricinctum in solid corn culture: Structural analysis and effects on mitochondrial respiration

Enniatins (ENs) are secondary fungal metabolites with hexadepsipeptidic chemical structure and they possess a number of potent biological activities that can contaminate several kind of food and foodstuffs increasing the exposure risk for consumers. ENs are produced by several Fusariun strains including Fusarium subglutinans, Fusarium proliferatum and Fusarium tricinctum. Production of a mixture of ENs was performed by culturing F. tricinctum ITEM 9496 on white corn as substrate. The solid culture components were dried and subsequently extracted with water/methanol (50/50 v/v, 0.5% NaCl), homogenised, filtered, extracted by ethyl acetate and analysed by liquid chromatography with diode array detection (LC-DAD). The crude extract was first separated by low pressure liquid chromatography (LPLC) and then further purified by liquid chromatography (LC), resulting in six compounds with a purity higher than 95% as calculated by 1H NMR, and with a yield of 30–300mg per compound. The chemical structures of the ENs were determined by liquid chromatography coupled to mass spectrometry (LC–MS) and nuclear magnetic resonance (NMR). The biological activity of the resulting ENs was determined using a mitochondrial respiration test. We discovered that all the ENs studied induced an increase in the mitochondrial respiration resulting in uncoupling of the oxidative phosphorylation. This effect was most likely due to flux of K+ ions into the mitochondrial matrix. The order of potency of the ENs derivatives was: A1>B1>B>A>B4>J1. These results suggest a correlation between the chemical structures and bioactivity and confirm the severe risks for human associated with consumption of enniatins.

A multiplex real-time PCR method using hybridization probes for the detection and the quantification of Fusarium proliferatum, F. subglutinans, F. temperatum, and F. verticillioides

Maize contamination with Fusarium species is one of the major sources of mycotoxins in food and feed derivates. In the present study, a LightCycler® real-time PCR method using hybridization probes was developed for the specific identification, detection, and quantification of Fusarium proliferatum, Fusarium subglutinans, Fusarium temperatum, and Fusarium verticillioides, four mycotoxin-producing pathogens of maize. Primers and hybridization probes were designed to target the translation elongation factor 1α (EF-1α) gene of F. subglutinans and F. temperatum or the calmodulin (Cal) gene of F. proliferatum and F. verticillioides. The specificity of the real-time PCR assays was confirmed for the four Fusarium species, giving no amplification with DNA from other fungal species commonly recovered from maize. The assays were found to be sensitive, detecting down to 5 pg and 50 pg of Fusarium DNA in simplex and multiplex conditions respectively, and were able to quantify pg-amounts of Fusarium DNA in artificially Fusarium-contaminated maize samples. The real-time PCR method developed provides a useful tool for routine identification, detection, and quantification of toxigenic Fusarium species in maize.

Near-infrared (NIR) hyperspectral imaging and multivariate image analysis to study growth characteristics and differences between species and strains of members of the genus Fusarium

Near-infrared (NIR) hyperspectral imaging was used to study three strains of each of three Fusarium spp. (Fusarium subglutinans, Fusarium proliferatum and Fusarium verticillioides) inoculated on potato dextrose agar in Petri dishes after either 72 or 96 h of incubation. Multivariate image analysis was used for cleaning the images and for making principal component analysis (PCA) score plots and score images and local partial least squares discriminant analysis (PLS-DA) models. The score images, including all strains, showed how different the strains were from each other. Using classification gradients, it was possible to show the change in mycelium growth over time. Loading line plots for principal component (PC) 1 and PC2 explained variation between the different Fusarium spp. as scattering and chemical differences (protein production), respectively. PLS-DA prediction results (including only the most important strain of each species) showed that it was possible to discriminate between species with F. verticillioides the least correctly predicted (between 16 and 47 % pixels correctly predicted). For F. subglutinans, 78–100 % pixels were correctly predicted depending on the training and test sets used. Similarly, the percentage correctly predicted values of F. proliferatum were 60–80 %. Visualisation of the mycelium radial growth in the PCA score images was made possible due to the use of NIR hyperspectral imaging. This is not possible with bulk spectroscopy in the visible or NIR regions. FigurePrincipal component 1 score image showing differences between colonies. F. subglutinans (MRC 0115) are top left followed by F. proliferatum (MRC 2301) and F. verticillioides (MRC 0826).