Differential proteomic analysis of proteins in wheat spikes induced by Fusarium graminearum

Scab, caused by Fusarium graminearum, is a serious spike disease in wheat. To identify proteins in resistant wheat cultivar Wangshuibai induced by F. graminearum infection, proteins extracted from spikes 6, 12 and 24 h after inoculation were separated by 2-DE. Thirty protein spots showing 3-fold change in abundance when compared with treatment without inoculation were characterized by MALDI-TOF MS and matched to proteins by querying the mass spectra in protein databases or the Triticeae EST translation database. Based on their volume profiles, these proteins were classified into four categories. The first one fell off rapidly at the initial inoculation and then rose at 12 or 24 hai, the second one decreased considerably after inoculation and remained at low level, the third one rose at the initial inoculation and then declined at 12 or 24 hai, the forth one showed steady increase after inoculation and maintained at a high level. Many of the proteins identified in the first two categories are related to carbon metabolism and photosynthesis. While most of proteins identified in the last two categories are related to stress defense of plants, indicating that proteins associated with the defense reactions were activated or translated shortly after inoculation.     

Toxigenic Fusarium species infecting wheat heads in Poland

Toxigenic Fusarium species are common pathogens of wheat and other cereals worldwide. In total, 449 wheat heads from six localities in Poland, heavily infected with Fusarium during 2009 season, were examined for Fusarium species identification. F. culmorum was the most common species (72.1% on average) with F. graminearum and F. avenaceum the next most commonly observed, but much less frequent (13.4 and 12.5% respectively). F. cerealis was found in 1.8% of all samples, and F. tricinctum was found only in one sample (0.2%). Subsequent quantification of the three major mycotoxins (deoxynivalenol, zearalenone and moniliformin) in grain and chaff fractions with respect to associated prevailing pathogen species uncovered the following patterns. Moniliformin (MON) was found in low amounts in all samples with F. avenaceum present. In contrast, deoxynivalenol (DON) and zearalenone (ZEA) were the contaminants of F. culmorum- and F. graminearum-infected heads. The highest concentration of DON was recorded in grain sample collected in Radzików (77 µg g^?1). High temperatures in Central Poland during July and August accompanied with high rainfall in July were responsible for this high DON accumulation. Trichothecene, zearalenone, enniatin and beauvericin chemotypes were identified among 21 purified isolates using gene-specific PCR markers.     

Exercise changes volatiles in exhaled breath assessed by an electronic nose

Exercise-caused metabolic changes can be followed by monitoring exhaled volatiles; however it has not been previously reported if a spectrum of exhaled gases is modified after physical challenge. We have hypothesized that changes in volatile molecules assessed by an electronic nose may be the reason for the alkalization of the exhaled breath condensate (EBC) fluid following physical exercise.Ten healthy young subjects performed a 6-minute running test. Exhaled breath samples pre-exercise and post-exercise (0 min, 15 min, 30 min and 60 min) were collected for volatile pattern ("smellprint") determination and pH measurements (at 5.33 kPa CO2), respectively. Exhaled breath smellprints were analyzed using principal component analysis and were related to EBC pH.Smellprints (p=0.04) and EBC pH (p=0.01) were altered during exercise challenge. Compared to pre-exercise values, smellprints and pH differed at 15 min, 30 min and 60 min following exercise (p<0.05), while no difference was found at 0 min post-exercise. In addition, a significant correlation was found between volatile pattern of exhaled breath and EBC pH (p=0.01, r=-0.34).Physical exercise changes the pattern of exhaled volatiles together with an increase in pH of breath. Changes in volatiles may be responsible for increase in EBC pH.     

A piezoelectric biosensor as an olfactory receptor for odour detection: electronic nose

Humans can detect and differentiate the presence of different odours even at trace levels of these odorous compounds. The odour quantification of any particular samples is normally based on conventional panel decisions. Other analytical instruments could be used to detect trace levels of odorous molecules. This study presents the results of a biological sensor system subject to different odorants. The system consists of a sensor in which the isolated olfactory receptor proteins (ORPs) from bullfrogs (Rana spp.) were coated onto the surface of a piezoelectric (PZ) electrode, similar to the mechanism of human olfaction. The PZ crystal served as a signal transducer. The results indicate rapid (about 400 s), reversible, and longterm (up to 3 months) stable responses to different volatile compounds such as n-caproic acid, isoamyl acetate, n-decyl alcohol, beta-ionone, linalool, and ethyl caporate. The sensitivity of the sensor ranges from 10(-6)-10(-7) g, fully correlated with the olfactory threshold values of human noses. An array of six sensors consisting of five fractionated ORPs and one referenced phospholipid probe is able to respond to different odorants and form a typical fingerprint for each odorant.     

Emetic material associated with Fusarium species in cereal grains and artificial media

Substances which cause emesis in pigeons were extracted from corn (Zea mays) artificially inoculated with Fusarium graminearum and from liquid culture medium inoculated with F. moniliforme, F. roseum, F. poae, F. culmorum, and F. nivale. Emetic preparations were obtained also from infected wheat (Triticum aestivum L. em. Thell), (Hordeum vulgare L. em. Lam), and durum (Triticum durum Desf). Partial purification resulted from chromatography with columns of cellulose and DEAE cellulose and with thin layers of silica gel. Two active materials were obtained from liquid culture of F. moniliforme but only one from infected cereals. Emetic preparations from F. moniliforme and infected cereals contained a polypeptide as a minor component. Ultraviolet and infrared spectrums, elemental analyses, refractive indices, and amino acid composition of the emetic from corn and one of the emeties from liquid culture of F. moniliforme were similar but not identical. Attempts to crystalline these emetics and to characterize them were unsuccessful.     

Variation in the spectrum of Fusarium species on winter wheat

In 1998–2000 a monitoring of the spectrum of Fusarium species on winter wheat was carried out in the Rhineland. The epidemic spread ofFusarium spp. on wheat plants during growing season was investigated as well as the grain contamination after harvest.F avenaceum was the Fusarium species isolated most frequently followed byF culmorum, F poae andF graminearum. Microdochium nivale occurred considerably only in 1998. Both, susceptibility and plant height of the cultivars were correlated to the incidence of Fusarium species /M nivale on harvested kernels; interactions with cropping intensities were detected. The incidence ofF poae seemed to be independent of the cultivar-specific Fusarium susceptibility. Despite the lack of disease symptoms, between growth stages 45–85 mycelium ofFusarium spp. was detectable in the leaves as well as conidia on the leaf surfaces.     

Evaluation of an electronic nose for the early detection of organic overload of anaerobic digesters

This study aimed at analysing the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An array of non specific metal oxide semiconductor gas sensors were used to detect process faults due to organic overload events in twelve 1.8-L anaerobic semi-continuous reactors. Three different load strategies were followed: (1) a cautious organic load (1.3 gVS L^?1 day^?1); (2) an increasing load strategy (1.3–5.3 gVS L^?1 day^?1) and (3) a cautious organic load with load pulses of up to 12 gVS L^?1 day^?1. A first monitoring campaign was conducted with three different substrates: sucrose, maize oil and a mix of sucrose/oil during 60 days. The second campaign was run with dry sugar beet pulp for 45 days. Hotelling’s T ² value and upper control limit to a reference set of digesters fed with a cautious OLR (1.3 gVS L^?1 day^?1) was used as indirect state variable of the reactors. Overload situations were identified by the e-nose apparatus with Hotelling’s T ² values at least four times higher in magnitude than the upper control limit of 23.7. These results confirmed that the e-nose technology appeared promising for online detection of process imbalances in the domain of anaerobic digestion.     

Seasonal variations of Fusarium species in wheat fields in Upper Egypt

Abstract

Populations of the genus Fusarium in wheat fields were studied within the crop-growing season at Qena area (Upper Egypt) using two different types of media (DCPA and DRBA) at 25°C. Fourteen Fusarium species were isolated during this study, namely F. anthophilum, F. aquaeductuum, F. chlamdosporum, F. dimerum, F. merismoides, F. moniliforme, F. oxysporum, F. poae, F. proliferatum, F. sambucinum, F. scripi, F. solani, F. sporotrichioides and F. subglutinans. Fusarium merismoides, F. oxysporum and F. sambucinum were the most common Fusarium species isolated from different wheat plant parts (rhizosphere and rhizoplane) as well as from the wheat fields (soil and air). Fusarium spp. rarely appeared at the beginning of the season and increased sharply between January to March and decreased slightly or sharply at the end of the season according to the type of media and isolation source.     

Detection and identification of fungal species by electronic nose technology: A systematic review

A rapid and effective identification of fungal species is essential for numerous applications, and electronic nose systems are being proposed as suitable alternatives to currently available fungi identification techniques. Hence, the present review aims to unveil all published information concerning fungi identification by electronic nose systems.A systematic review of the literature was conducted according to the PRISMA guidelines. A total of 16 articles met the inclusion criteria and were included in the analysis. The results of the reviewed studies demonstrated that effective detection of fungi was possible through sensor-based electronic nose systems, which may actually function as a mycotoxin screening tool for several applications.The obtained results suggest that the sensor-based electronic nose systems may not only screen different fungi genera, but also identify the associated species. This technology has already been experimented in several fields, from food industry to clinical practice.By summarizing these results, the present review may accelerate the standardization of electronic noses in fungi detection and discrimination, allowing a faster and more efficient screening of samples.     

Predicting sporulation events in a bioreactor using an electronic nose

An electronic nose (EN) based on a non- specific multi-sensor array was used to accurately estimate sporulation events and the spore concentration of Bacillus subtilis cultures. The array included 6 metal oxide sensors (MOS), 10 metal oxide semiconductor field effect transistors (MOSFET), one CO(2) infrared sensor and one humidity sensor. The EN was used to monitor the gas emissions from B. subtilis bioreactions during both batch and fed-batch operation. The signal pattern produced by the sensors was evaluated by principal component analysis (PCA) and training cultivations were used to build a model. The arc length of the PCA trajectories was successfully correlated to the off-line spore count; a strong linear correlation (R(2) = 0.992) between the numerical integration of the curves and the measured spore concentration was established. The fast responses of the sensors in combination with the robust correlation with the off-line determination of spore concentration establish this EN device as a convenient tool for monitoring sporulation events in bioprocesses.     

Quantification of Fusarium graminearum in infected wheat by species specific real-time PCR applying a TaqMan Probe

A new real-time PCR based method was developed for the species-specific detection, identification and quantification of Fusarium graminearum in planta. It utilizes a TaqMan hybridisation probe targeting the beta-tubulin gene and a plasmid standard. The assay is highly specific giving no product with DNA of closely related species. It is very sensitive, detecting down to five gene copies per reaction, and is able to produce reliable quantitative data over a range of six orders of magnitude.     

Phylogenetic diversity of Fusarium incarnatum-equiseti species complex isolated from Spanish wheat

Wheat is the most important cereal grown in the European Union and Spain is its fifth largest wheat producer. There is little information about Fusarium species associated with wheat in Spain. Phylogenetic diversity of 51 strains belonging to Fusarium incarnatum-equiseti species complex (FIESC) isolated from Spanish wheat was investigated using partial sequences of the translation elongation factor gene (EF-1α). Maximum-parsimony and Bayesian analysis of aligned DNA sequences resolved 18 haplotypes and 7 phylogenetic species. Strains morphologically identified as F. equiseti belonged to two different phylogenetic species, FIESC-5 and FIESC-14. Some correlation between phylogenetic species and geographical region was found. The present results highlight the potential contribution of FIESC to the mycotoxin contamination of Spanish wheat.     

Differential drought-induced modulation of ozone tolerance in winter wheat species

Recent reports challenge the widely accepted idea that drought may offer protection against ozone (O(3)) damage in plants. However, little is known about the impact of drought on the magnitude of O(3) tolerance in winter wheat species. Two winter wheat species with contrasting sensitivity to O(3) (O(3) tolerant, primitive wheat, T. turgidum ssp. durum; O(3) sensitive, modern wheat, T. aestivum L. cv. Xiaoyan 22) were exposed to O(3) (83ppb O(3), 7h d(-1)) and/or drought (42% soil water capacity) from flowering to grain maturity to assess drought-induced modulation of O(3) tolerance. Plant responses to stress treatments were assessed by determining in vivo biochemical parameters, gas exchange, chlorophyll a fluorescence, and grain yield. The primitive wheat demonstrated higher O(3) tolerance than the modern species, with the latter exhibiting higher drought tolerance than the former. This suggested that there was no cross-tolerance of the two stresses when applied separately in these species/cultivars of winter wheat. The primitive wheat lost O(3) tolerance, while the modern species showed improved tolerance to O(3) under combined drought and O(3) exposure. This indicated the existence of differential behaviour of the two wheat species between a single stress and the combination of the two stresses. The observed O(3) tolerance in the two wheat species was related to their magnitude of drought tolerance under a combination of drought and O(3) exposure. The results clearly demonstrate that O(3) tolerance of a drought-sensitive winter wheat species can be completely lost under combined drought and O(3) exposure.     

Production of refusal factors by Fusarium strains on grains.

Corn fermented with strains of Fusarium culmorum NRRL 3288, F. poae NRRL 3287, F. moniliforme NRRL 3197, and F. nivale NRRL 3289 at 28 degrees C for 13 days was refused when fed to 30- to 60-pound (about 13.6- to 27.2-kg) swine. Analyses of the refused corn for trichothecenes (T-2, HT-2, acetyl T-2, fusarenon-X, and vomitoxin) showed that only the corn fermented with F. culmorum contained vomitoxin. None of these five trichothecenes could be detected in the other refused corn.F. culmorum grown on rice at 28 degrees C for 13 days also produced vomitoxin.     

Detection of pest species with different ratios in tea plant based on electronic nose

It is highly possible that tea (Camellia sinensis) plant is attacked by more than one pest species at the same time, and the determination of their proportion is of great significance to the management of tea plants. However, there are no literatures focusing on it previously. In this work, two pest species (Ectropis obliqua and Ectropis grisescens) in six different ratios (10:0, 8:2, 6:4, 4:6, 2:8 and 0:10) were applied to attack tea plants and electronic nose (E‐nose) was employed to detect them, labelled as group 10:0, 8:2, 6:4, 4:6, 2:8 and 0:10, respectively. Two prediction methods were applied to predict the ratio of E. obliqua and E. grisescens attacking tea plant and their performances were compared. The first method employed regression algorithm for prediction analysis based on the whole E‐nose data directly. The second method classified tea plants into three main classes (the first class contained group 10:0, the second class contained groups 8:2, 6:4, 4:6 and 2:8, and the third class contained group 0:10) first, then regression algorithm was applied to deal with the second class for prediction analysis. The results showed that the second method had a better performance. Its discrimination results showed 100% of the correct classification rate for training set and 93.75% for testing set. Meanwhile, its prediction results showed 0.0005 of root mean square error (RMSE) for calibration set, 0.0064 for validation set and 99.07% of fitting correlation coefficients (R²) for calibration set, 91.22% for validation set, which were acceptable for prediction analysis and proved that E‐nose was a feasible technique for pests' ratio prediction.     

Quantification of trichothecene-producing Fusarium species in harvested grain by competitive PCR to determine efficacies of fungicides against Fusarium head blight of winter wheat

We developed a PCR-based assay to quantify trichothecene-producing Fusarium based on primers derived from the trichodiene synthase gene (Tri5). The primers were tested against a range of fusarium head blight (FHB) (also known as scab) pathogens and found to amplify specifically a 260-bp product from 25 isolates belonging to six trichothecene-producing Fusarium species. Amounts of the trichothecene-producing Fusarium and the trichothecene mycotoxin deoxynivalenol (DON) in harvested grain from a field trial designed to test the efficacies of the fungicides metconazole, azoxystrobin, and tebuconazole to control FHB were quantified. No correlation was found between FHB severity and DON in harvested grain, but a good correlation existed between the amount of trichothecene-producing Fusarium and DON present within grain. Azoxystrobin did not affect levels of trichothecene-producing Fusarium compared with those of untreated controls. Metconazole and tebuconazole significantly reduced the amount of trichothecene-producing Fusarium in harvested grain. We hypothesize that the fungicides affected the relationship between FHB severity and the amount of DON in harvested grain by altering the proportion of trichothecene-producing Fusarium within the FHB disease complex and not by altering the rate of DON production. The Tri5 quantitative PCR assay will aid research directed towards reducing amounts of trichothecene mycotoxins in food and animal feed.     

Production of chitinase by Fusarium species

The presence of chitinase activity without inducers in the enzymic precipitates from the culture fluid of 25-day-old autolyzed cultures of 17 Fusarium species has been studied. In all cases endochitinase and -N-acetylglucosaminidase activities were found. The chitinase activity as a joint action of these two enzymes with production of N-acetylglucosamine was also determined. A correlation among endochitinase, -N-acetylglucosaminidase, and chitinase was always found. Fusarium oxysporum f.sp. lini, F. subglutinans, and F. moniliforme were the best producers of chitinase activity. Fusarium species could be a good source of chitinases for production by fungi.     

Application of electronic nose technology for the detection of fungal contamination in library paper

Studies were carried out in vitro on a cellulose based agar at two water activities (a_w,0.975,0.995) and on three types of paper at two relative humidities (75, 100% RH) for the potential for differentiation of contamination and colonisation by Aspergillus terreus, A. holandicus and Eurotium chevalieri. In vitro studies showed that conducting polymer sensor array gave different responses to each of these species when grown on cellulose agar at both a_w levels. Discriminant function analyses of the data showed differentiation of the controls from the spoilage fungi. Cluster analysis gave a significant (P=0.05) separation of the control and each spoilage fungus. In situ studies on three types of paper showed that using natural substrates the volatile patterns produced by each of these fungi was different from each other and from the control. The results obtained were better at the higher humidity. The three paper types could be successfully differentiated into clusters. For a single paper type, differentiation of controls from spoilage fungal treatments was better at the higher humidity. This study has shown that this technology has potential for the early detection of fungal contamination in library materials and archives for the improved protection of cultural heritage.