Plant lignans inhibit growth and trichothecene biosynthesis in Fusarium graminearum.

UNLABELLED: Lignans are a group of diphenolic compounds with anticancer and antioxidant properties which are present in various grains, although their effect on toxigenic fungi has been poorly examined to date. In this study, the impact of the plant lignans pinoresinol and secoisolariciresinol on growth and trichothecene biosynthesis by five Fusarium graminearum strains of different chemotypes was examined in vitro. Both tested lignans exhibited radial growth inhibition against the fungal strains. RT-qPCR analyses of tri4, tri5 and tri11 genes encoding the first steps of the trichothecene biosynthesis pathway revealed a decrease in tri mRNA levels in lignan-treated fungal cultures. Correspondingly, decreased accumulation of toxins in lignan-treated cultures was confirmed by GC-MS analysis. This is the first study to demonstrate the inhibitory effect of both pinoresinol and secoisolariciresinol on growth and trichothecene biosynthesis in F. graminearum. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of the regulation of trichothecene production in Fusarium graminearum by environmental cues is key to the design of novel strategies to reduce mycotoxin levels in grains. Here, we show that the lignans pinoresinol and secoisolariciresinol, which occur in wheat grains, inhibit radial growth and decrease trichothecene levels in five F. graminearum strains. RT-qPCR analysis reveals that the reduction in trichothecene level in lignan-treated fungal cultures is associated with decreased mRNA transcript levels for the tri4, tri5 and tri11 genes that are involved in the trichothecene biosynthesis pathway.

Ergosterol as an indicator of the presence of microscopic fungi in eggs for human consumption produced in different husbandry systems.

Ergosterol (ERG) content, being an indicator of fungal biomass, was analyzed in samples of eggshell, egg white, and egg yolk from eggs from farms with intensive management systems of layer hens (i.e., cage and litter housing). Moreover, analogous samples were analyzed from eggs from farms in the western central part of Poland, where layer hens were kept in the organic system. In all samples, the highest ERG concentration was found in shells and the lowest in egg white, whereas ERG was not found in egg yolk. When comparing investigated housing systems, a higher concentration of the analyzed metabolite was detected in eggs from litter housing than in eggs from cage housing. Concentrations of ERG in samples of eggs from organic husbandry were highly varied, ranging from 2.44 to 42.67 mg/kg in shells and from 0.28 to 16.11 mg/kg in egg white.

Scanning electron microscopy of Fusarium damaged kernels of spring wheat.

Kernels of five wheat cultivars (Triticum aestivum) of different bread-making quality were examined. Grown under field conditions, heads of wheat were inoculated in the flowering stage with an aqueous suspension of Fusarium culmorum conidia. Wheat heads were collected from the control and inoculated plots at full maturity. Control (non-inoculated) kernels without any symptoms of disease and Fusarium damaged kernels (FDK) were examined under scanning electron microscopy (SEM). Examination of the FDK fraction confirmed localisation of Fusarium hyphae on the surface and inside the tissues of kernels. Observations of the endosperm from Fusarium infected kernels revealed presence of fungal hyphae in the endosperm and some characteristic structural changes in many of its regions, such as partial or complete lack of the protein matrix, damage to large and small starch granules caused by fungal amylolytic enzymes, disappearance of small starch granules as the colonisation progressed, complete disappearance of the starchy endosperm under severe infection. Fungal colonisation of the endosperm and structural changes in its area were highly variable traits within the FDK fraction of a given cultivar.

Genetic determination of variability of barley doubled haploids inoculated with Fusarium culmorum (W.G.Sm.) Sacc. with regard to mycotoxin accumulation and reduction in yield traits.

The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in 3-year field experiment on the basis of reduction in yield traits and myotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assessed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e.regarding the influence of years and year x genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentrations and 30% in DON concentration resulted form genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance x dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from segregation of 5-6 effective factors, DON contents from 4 factors, while NIV content from 5 factors.

Levels of fungi and mycotoxins in samples of grain and grain dust collected on farms in Eastern Poland.

Ten samples of stored wheat grain and 10 samples of settled grain dust released during machine threshing of wheat grain were collected on 10 farms located in Lublin province (eastern Poland). The samples were examined for the concentration of total microfungi, Fusarium species, fusariotoxins (moniliformin, deoxynivalenol, nivalenol), and ochratoxin. Microfungi able to grow on malt agar were present in 30% of grain samples (median for all examined samples = 0, range 0-227.5 x 10(3) cfu/g) and in all samples of grain dust (median = 977.5 x 10(3) cfu/g, range 115.0-16,700.0 x 10(3) cfu/g). Fusarium species (F. avenaceum) were found only in 10% of grain samples (median = 0, range 0-800.0 x 10(3) cfu/g), but in 90% of grain dust samples (median = 1,150 x 10(3) cfu/g, range 5.5-10,060.0 x 10(3) cfu/g). The species F. avenaceum, F. culmorum, F. graminearum, F. poae and F. sporotrichioides were isolated respectively from 50%, 10%, 20%, 40% and 20% of examined grain dust samples. The presence of the mycotoxins produced by Fusarium (moniliformin, deoxynivalenol, and nivalenol) was found altogether in 70% of wheat grain samples (median = 0.1275 microg/g, range 0-1.480 microg/g) and in 90% of grain dust samples (median = 0.350 microg/g, range 0-1.090 microg/g). Moniliformin (MON), deoxynivalenol (DON), and nivalenol (NIV) were each detected in 40% of grain samples, and respectively in 80%, 40%, and 40% of grain dust samples. Ochratoxin A (OTA) was detected in 60% of grain samples and in 60% of grain dust samples (median in both cases was 0.0005 microg/g). The concentrations of F. poae (p<0.05) and of total Fusarium species (p<0.01) in grain samples, and the concentrations of F. culmorum and F. graminearum (p<0.05) in grain dust samples were significantly correlated with the concentration of deoxynivalenol. The concentrations of F. poae (p<0.05) and of total Fusarium species (p<0.01) in grain dust samples were significantly correlated with the concentration of total fusariotoxins. Moreover, the concentration of total Fusarium species in grain dust samples was significantly correlated with the concentration of nivalenol (p<0.05). In conclusion, the majority of samples of wheat grain and grain threshing dust collected on farms in eastern Poland contained notable quantities of fusaria and/or fusariotoxins. This fact poses a potential risk of mycotoxicoses to agricultural workers exposed to grain dust when handling wheat during threshing, unloading, shuffling, and other farm occupations.

Decomposition of non-ionic surfactant Tergitol TMN-10 by the Fenton process in the presence of iron oxide nanoparticles.

The aim of our studies was to determine the efficiency of decomposition of non-ionic surfactant by the Fenton method in the presence of iron nanocompounds and to compare it with the classical Fenton method. The subject of studies was water solutions of non-ionic detergent Tergitol TMN-10 used in textile industry. Water solutions of the surfactant were subjected to treatment by the classical Fenton method and to treatment in the presence of iron nanocompounds. In the samples of liquid solutions containing the surfactant, chemical oxygen demand (COD) and total organic carbon (TOC) were determined. The Fenton process was optimized based on studies of the effect of compounds used in the treatment, doses of iron and nanoiron, hydrogen peroxide and pH of the solution on surfactant decomposition. Iron oxide nanopowder catalyzed the process of detergent decomposition, increasing its efficiency and the degree of mineralization. It was found that the efficiency of the surfactant decomposition in the process with the use of iron nanocompounds was by 10 to 30 % higher than that in the classical method. The amounts of formed deposits were also several times smaller.

University of Lodz an electron spectrometer--a new conversion-electron spectrometer for "in-beam" measurements.

The designed and constructed at the University of Lodz an electron spectrometer is devoted to "in-beam" measurements. The apparatus is characterized by high efficiency up to 9%, good energy resolution (FWHM = 5 keV at 482 keV) and, what is very important good suppression of delta electrons, positrons, and photons emitted by the targets. This achievement was obtained using a combination of magnetic field in two different layouts: perpendicular and parallel to the axis of the spectrometer being orthogonal to the beamline. The conversion-electron spectrometer coupled to the EAGLE array was successfully tested in an "in-beam" measurement.

Fusarium toxins and total fungal biomass indicators in naturally contaminated wheat samples from north-eastern Poland in 2003.

Concentrations of fungal metabolites were measured in 32 wheat grain samples from north-eastern Poland in 2003. The samples originated from fields cultivated conventionally (but varying in chemical protection level) or cultivated organically. Concentrations of Fusarium toxins (HT-2, DON, 3-AcDON, NIV), trichodiene, microbial biomass indicators (fungal ergosterol and general adenosine 5'-triphosphate (ATP)) and seed vigour were assessed. A large variation between samples was observed, depending on their origin. Seed from organic farms contained similar amounts of Fusarium toxins but more ergosterol and ATP than conventionally grown and chemically protected seed. The highest levels of toxins and ergosterol were detected in samples from conventional cultivation lacking chemical protection. Intensive agronomic practices (including complete chemical protection) significantly lowered the levels of ergosterol, ATP and trichodiene, as compared with other cultivation systems.

Observation of a rotational band in the odd-Z transfermium nucleus 101251Md.

A rotational band has been unambiguously observed in an odd-proton transfermium nucleus for the first time. An in-beam gamma-ray spectroscopic study of 101/251Md has been performed using the gamma-ray array JUROGAM combined with the gas-filled separator RITU and the focal plane device GREAT. The experimental results, compared to Hartree-Fock-Bogolyubov calculations, lead to the interpretation that the rotational band is built on the [521]1/2(-) Nilsson state.

128Cs as the best example revealing chiral symmetry breaking.

The results of the Doppler-shift attenuation method lifetime measurements in partner bands of 128Cs and 132La are presented. Experimental reduced transition probabilities in 128Cs are compared with theoretical calculations done in the frame of the core-quasiparticle coupling model. The electromagnetic properties, energy and spin of levels belonging to the partner bands show that 128Cs is the best known example revealing the chiral symmetry breaking phenomenon.

Distribution of deoxynivalenol in barley kernels infected by Fusarium.

Deoxynivalenol (DON) in concentration range 0.1-156.6 mg/kg, was found in 48 samples of barley kernels collected from heads with visible symptoms of head scab after inoculation in a field with Fusarium culmorum and Fusarium graminearum. Four fractions of the kernels were collected according to their size: > 2.8 mm (I); < or = 2.8-2.5 mm (II); > 2.5-2.2 mm (III) and < 2.2 mm (IV). In plants infected with Fusarium (when compared to the control) number of kernels in the fraction of the largest kernels (> 2.8 mm) decreased from 38% to 18%, while in small kernels (fractions < 2.5-2.2 mm and < 2.2 mm) numbers increased respectively from 16 to 22% and from 14 to 28%. Average level of DON concentration in these fractions was as follows: (I) 3.5 mg/kg--(4%); (II) 9.1 mg/kg--(16%); (III) 35.5 mg/kg--(29%) and (IV) 43.3 mg/kg--(51%). The highest DON accumulation was observed in fraction of small (< 2.5 mm) kernels. The fraction contributed from 77% up to 94% of total DON content in kernels with low (< 2 mg/kg) and high (> 100 mg/kg) contamination level, respectively. These results indicate that as well level of samples contamination with DON as human and animal health risk in consequence can be reduced by kernels selection (according their size) followed by rejection of the smallest kernels fraction.

Mycotoxins in cereal grain (part 15). Distribution of deoxynivalenol in naturally contaminated wheat kernels.

The analysis of deoxynivalenol (DON) in naturally infected wheat samples, after having been separated into four fractions through laboratory sieves, showed very low levels of DON in the fraction of largest kernels >2.8 mm (0 up to 1 mg/kg). The highest concentration of DON was found in fractions 2.2 to 2.5 mm and <2.2mm with up to 14mg/kg and 15mg/kg DON, respectively. In two samples (fractions <2.2mm) nivalenol was detected in concentrations up to 1,4mg/kg.

Natural contamination of oat with group A trichothecene mycotoxins in Poland.

Ninety-nine naturally contaminated oat grain samples were collected in 12 plant breeding stations in different parts of Poland. T-2 toxin, HT-2 toxin and diacetoxyscirpenol (DAS) levels were determined by gas chromatography with mass selective detection (GC-MS). HT-2 was the major toxin with an incidence of 24% and its average level in positive samples was 21 microg kg(-1). The incidence of T-2 and DAS was 15 and 12%, and their average levels were 60 and 23 microg kg(-1), respectively. The highest concentrations of HT-2, T-2 and DAS were 47, 703 and 111 microg kg(-1), respectively. Sixty-five samples were free of detectable amounts of the toxic metabolites analysed.

Susceptibility of selected winter wheat cultivars produced in Poland to Fusarium head blight.

The susceptibility of six winter wheat cultivars toFusarium head blight has beenstudied. The lowest infected plants intensity, mean degree of head damage and fusariosis index exhibited cultivar Grana which also cumulated the lowest amount of trichothecenes (DON and derivatives ). Possibility to produce NIV by Polish strains has been found.in F.graminearum.

Deoxynivalenol and 3-acetyldeoxynivalenol and Fusarium species in winter triticale.

Fusarium species infecting heads of Triticale and mycotoxins presence in infected kernels and chaff were studied during two seasons. The most important species observed on infected heads were in 1986F. avenaceum (39%),F. nivale (21%),F. culmorum (20%),F. graminearum (14%), and others (6%). In 1987 after long and snowy winterF. nivale dominated (64%), followed byF. avenaceum (24%),F. culmorum (6%), andF. graminearum (5%).The mycotoxins deoxynivalenol (DON) and 3-acetyl DON were present in all 11 subsamples of kernels from heads infected byF. culmorum and/orF. Graminearum (1.6-16.4 mg and 0.7-2.4mg/kg, respectively). Chaff from the same subsamples contained 9.9-33.2mg/kg of DON and 5.2-16.0mg/kg of 3-AcDON. Kernels with visibleFusarium-damage contained 2.4-31.2 mg/kg of DON and 1.2-6.0 mg/kg of 3-AcDON. Remaining part of kernels without symptoms of visibleFusarium-damage contained only DON in an amount of 0.9-5.9 mg/kg.

Toxicity of Fusarium metabolites to brine shrimps (Artemia salina).

Extracts of the followingFusaria cultures, isolated from cereals were examined for toxicity to Artemia salina:F. avenaceum (6 isolates),F. crookwellense (7),F. graminearum (11),F. nivale (5) andF. Sporotrichioides (2). The same cultures, growing on wheat grain, were assayed also mycotoxins presence using TLC method. Most toxic were found cultures ofF. Sporotrichioides and results of bioassay was similar to results of their TLC analysis. We found cultures of newly described speciesF. Crookwellense to be more toxic than cultures ofF. Graminearum.

Mycotoxins in cereal grain. Part 13. Deoxynivalenol and 3-acetyl-deoxynivalenol in wheat kernels and chaff with head fusariosis symptoms.

In the period of harvest at 1987 field samples of wheat heads with fusariosis symptoms were collected in 18 provinces of Poland. Subsamples of heads infected with Fusarium culmorum (W.G.Sm) Sacc. and Fusarium graminearum Schwabe were analyzed for Fusarium metabolites. In fractions of kernels with visible Fusarium-damage deoxynivalenol (DON) was present in average amount of 18.7 mg/kg (range 9.6-25.3 mg/kg) and 3-acetyl DON 1.9 mg/kg. Fractions of kernels without symptoms of visible Fusarium-damage contained only DON at average 2 mg/kg (range 0.8-3.6 mg/kg). A method of approximate calculation of DON content in a given lot of grain is proposed which may be realized during samples grading.

Cumulation of mycotoxins in maize cobs infected withFusarium gramihearum.

Maize cobs withFusarium ear rot were collected at 1986 season and five infected byFusarium graminearum were analyzed for presence of triohothecenes and zearalenone. Collected material was subsampled forFusarium damaged kernels and corresponding axial stems and healthy looking kernels. All investigated cobs contained deoxynivalenol (DON) (range 18.0-131.5 mg/kg) and zearalenone (ZEA) (range 0.38-2.17 mg/kg), in four cobs 15-acetyl-deoxynivalenol (15-AcDON) (range 5.2-6.2 mg/kg) was present and two cobs besides three all metabolites contained 3-acetyl-deoxynivalenol (3-AcD0N) (range 0.5-0.8 mg/kg).The average of individual toxins amount in axial stems: in mg/kg was equal to: DON - 110.36, ZEA - 4.57, 15-AcD0N - 16.66, and 3-AcD0N - 1.32.Fusarium damaged kernels contained in average the following amount (mg/kg) of: DON 77.00, ZEA 0.98, 15-AcD0N 3.78 and 3-AcD0N 0.06. Healthy looking kernels contained DON 1.96 mg/kg and ZEA 0.07 mg/kg only. Cooccurrence of 3-AcDON and 15-AcDON in two samples was an interesting finding. The amount of DON in total cob was highly correlated (r = 0.94) with percentage ofFusarium damaged kernels in given ear.