Feruloyl-CoA 6'-Hydroxylase1-dependent coumarins mediate iron acquisition from alkaline substrates in Arabidopsis

Although iron (Fe) is one of the most abundant elements in the earth's crust, its low solubility in soils restricts Fe uptake by plants. Most plant species acquire Fe by acidifying the rhizosphere and reducing ferric to ferrous Fe prior to membrane transport. However, it is unclear how these plants access Fe in the rhizosphere and cope with high soil pH. In a mutant screening, we identified 2-oxoglutarate-dependent dioxygenase Feruloyl-CoA 6'-Hydroxylase1 (F6'H1) to be essential for tolerance of Arabidopsis (Arabidopsis thaliana) to high pH-induced Fe deficiency. Under Fe deficiency, F6'H1 is required for the biosynthesis of fluorescent coumarins that are released into the rhizosphere, some of which possess Fe(III)-mobilizing capacity and prevent f6'h1 mutant plants from Fe deficiency-induced chlorosis. Scopoletin was the most prominent coumarin found in Fe-deficient root exudates but failed to mobilize Fe(III), while esculetin, i.e. 6,7-dihydroxycoumarin, occurred in lower amounts but was effective in Fe(III) mobilization. Our results indicate that Fe-deficient Arabidopsis plants release Fe(III)-chelating coumarins as part of the strategy I-type Fe acquisition machinery.

On the toxicokinetics and the metabolism of deoxynivalenol (DON) in the pig

Eleven castrated male pigs weighing 88.1 +/- 3.9 kg on average were adapted to a diet containing DON (4.2 mg DON/kg) over a period of 7 days. Feed was given restrictively with 1.1 kg per meal (two meals per day). On the day of measurement, all pigs were slaughtered at different time intervals following the morning meal containing DON (1, 2, 3, 4, 5, 6, 8, 15, 18 and 24 h after feeding), with the exception of one pig which was slaughtered unfed. DON and de-epoxy-DON were analysed in serum and digesta from consecutive segments of the digestive tract (stomach, small intestine divided into three parts of a similar length, caecum, colon, rectum). DON was rapidly and nearly completely absorbed while passing through the stomach and the proximal small intestine. Maximum serum concentration appeared 4.1 h after the DON-containing meal and half of the systemically absorbed DON was eliminated after 5.8 h. De-epoxy-DON appeared in increasing proportions from the distal small intestine and reached approximately 80% of the sum of DON plus de-epoxy-DON in faeces collected from the rectum. It was concluded that de-epoxydation of DON, which primarily occurs in the hindgut, probably does not contribute much to a detoxification in the pig.

Effects of graded levels ofFusariumtoxin contaminated maize in diets for female weaned piglets

A dose response study was carried out with piglets to examine the effects of increasing amounts of Fusarium toxins in the diet on performance, clinical serum characteristics, organ weights and residues of zearalenone (ZON) and deoxynivalenol (DON) and their metabolites in body fluids and tissues. For this purpose, Fusarium toxin contaminated maize (1.2 mg ZON and 8.6 mg DON per kg maize) was incorporated into a maize based diet for piglets at 0, 6, 12.5, 25 and 50% at the expense of control maize. The experimental diets were tested on 100 female piglets allotted to 20 boxes (five animals per box) covering a body weight range of 12.4 +/- 2.2 kg to 32.5 +/- 5.6 kg. Voluntary feed intake and, consequently, body weight gain of the animals receiving the highest proportion of Fusarium toxin contaminated maize were significantly decreased while the feed conversion ratio was not affected by the treatment. The mean weight of the uterus related to the body weight of the animals of the same group was increased by almost 100% as compared to the control. For this group, significantly decreased values of total serum protein were determined, while the serum activity of the liver enzyme glutamate dehydrogenase and the serum concentration of the follicle stimulating hormone were decreased for all treatment groups receiving 6% contaminated maize or more in the diet. Serum concentrations of immuneglobulins were not consistently altered by the treatment. Corresponding to the dietary exposure, increasing concentrations of ZON and alpha-zearalenol were detected in the bile fluid, liver and in pooled urine samples. The metabolite beta-zearalenol was detected only in bile fluid. The total concentration of ZON plus its metabolites in bile fluid correlated well with the diet contamination (r = 0.844). DON was found in serum, bile fluid and pooled urine samples while de-epoxy-DON was detected only in urine. The serum concentration of DON correlated well with the respective toxin intake 3-4 h prior to slaughtering (r = 0.957). For all mentioned analyses of residues it has to be noted that toxin residues were detectable even if negligible concentrations were present in the diet.

Effects of graded levels of Fusarium toxin-contaminated wheat and of a detoxifying agent in broiler diets on performance, nutrient digestibility and blood chemical parameters

1. A growth experiment was carried out with male broilers from d 1 to d 35 of age in order to evaluate the effects of the addition of a detoxifying agent (Mycofix Plus, Biomin GmbH, Herzogenburg, Austria) at different dietary proportions of wheat (0, 16.5, 33, 49.5 and 66%) contaminated with Fusarium mycotoxins (21.2 mg of deoxynivalenol and 406 microg of zearalenone, ZON, per kg of wheat) on growth performance, nutrient and zearalenone balance and clinical-chemical parameters. 2. An increase in dietary mycotoxin concentration resulted in a linearly related decrease in feed intake, a slight decrease in weight gain and an improvement in feed to gain ratio. 3. Apparent protein digestibility and net protein utilisation were higher in diets containing exclusively Fusarium toxin-contaminated wheat than control diets. 4. The proportions of beta-zearalenol, alpha-zearalenol and ZON of total ZON metabolites in excreta of broilers fed on the diets containing the Fusarium toxin-contaminated wheat were approximately 3, 21 and 76%. 5. Serum antibody titres to Newcastle disease virus decreased in a linear fashion with increasing mycotoxin concentration in the diets, whereas other clinical-chemical serum parameters (liver cell and muscle cell necrosis indicating enzymes, haemoglobin, haematocrit, magnesium, inorganic phosphate) were not influenced by increasing Fusarium toxin concentrations. 6. Supplementation of the diets with Mycofix Plus decreased performance in a manner independent of mycotoxin concentration. Moreover, some clinical-chemical serum parameters were significantly altered due to Mycofix Plus but also independently of the dietary mycotoxin concentration.

Effects of graded levels of Fusarium toxin contaminated wheat in diets for fattening pigs on growth performance, nutrient digestibility, deoxynivalenol balance and clinical serum characteristics

A dose response study was carried out with pigs in order to examine the effects of increasing dietary deoxynivalenol (DON)-concentrations on performance, clinical serum characteristics, nutrient digestibility and DON-metabolism. For this purpose, wheat contaminated naturally with Fusarium toxins was incorporated into pig diets at increasing proportions to give calculated dietary DON-concentrations of 0, 2.3 and 4.6 mg/kg during the starter period of phase 1 (14 d) of the experiment, and 0/0, 1.2/1.4, 2.3/3.7 mg/kg starter/grower diet during phase 3 (56 d) of the experiment. Each diet was tested on 16 pigs of both sexes with an initial average live weight of approximately 28 kg. A recovery phase (phase 2, 21 d) was intercalated between phase 1 and 3 of the growth experiment where all groups were fed with the uncontaminated control diet since some pigs exposed to the highest dietary DON-concentration during phase 1 nearly completely refused the offered feed. Affected pigs completely recovered during this phase. In phase 3, when diets with lower DON-concentrations were fed, no differences in performance could be detected. Serum clinical characteristics (enzymes indicating liver damage, total protein, immunoglobulins) did not respond to increasing DON-concentration in the diets. DON-concentration in serum increased in a dose-response-related manner as dietary DON-concentration increased. However, this parameter was not or only weakly correlated to any of the examined performance parameters or serum characteristics. Also, nutrient digestibility of the diets and N-retention were not affected by treatments with the exception of crude fat digestibility which was not consistently influenced. Concentration of DON and its metabolite de-epoxy-DON increased in urine with increasing dietary DON-concentration in a strongly linearly related fashion. The proportion of the excretion of de-epoxy-DON of the total urinary excretion of DON plus de-epoxy-DON rose linearly up to approximately 4%. Total recovery of DON plus de-epoxy-DON as percentage of DON-intake varied between 45 and 57% and was not influenced by dietary DON-concentration. Only a very small fraction of approximately 0.1% of ingested DON was recovered in faeces.

Effects of the Fusarium toxin deoxynivalenol on tissue protein synthesis in pigs

The Fusarium toxin deoxynivalenol is known to be a potent protein synthesis inhibitor according to research in different in vitro and in vivo systems. However, the significance of this toxic feature was not yet evaluated for the pig. Therefore, an experiment was carried out to measure porcine tissue protein synthesis employing the so-called flooding dose technique using [(2)H(5)]-phenylalanine as tracer. A total of 25 male castrated pigs (initial weight of 23kg) were used. Seventeen pigs were fed the control diet (control) and eight the Fusarium toxin-contaminated diet (chronic oral deoxynivalenol (DON)) for approximately 4wks. Pigs recruited from the control group were treated with acute oral (n=7) and intravenous (i.v.) DON (n=5), and were exposed to the toxin once on the day of protein synthesis measurement. The DON-dose given prior to the beginning of protein synthesis measurement amounted to 2, 77, 83 and 53microg DONkg(-1) live weight for the control group, chronic oral DON-group, acute oral DON-group and acute i.v. DON-group, respectively. Protein synthesis expressed as fractional synthesis rate (FSR) was significantly reduced in kidneys, spleen and ileum of DON-exposed pigs with effects being less pronounced in the acute oral DON-group. FSR of liver, skeletal and heart muscle, mesenteric lymph nodes, duodenum, jejunum, jejunal mucosa cells, pancreas and lung were not affected by DON.

Arabidopsis thaliana G2-LIKE FLAVONOID REGULATOR and BRASSINOSTEROID ENHANCED EXPRESSION1 are low-temperature regulators of flavonoid accumulation

Flavonoid synthesis is predominantly regulated at the transcriptional level through the MYB-basic helix-loop-helix (bHLH)-WD40 (MBW) (MYB: transcription factor of the myeloblastosis protein family, WD40: tanscription factor with a short structural motif of 40 amino acids which terminates in an aspartic acid-tryptophan dipeptide) complex, and responds to both environmental and developmental stimuli. Although the developmental regulation of flavonoid accumulation in Arabidopsis thaliana has been examined in great detail, the response of the flavonoid synthesis pathway to abiotic stress (particularly low temperature) remains unclear. A screen of a Dissociation element (Ds) transposon-induced mutation collection identified two lines which exhibited an altered profile of phenylpropanoid accumulation following exposure to low-temperature stress. One of the mutated genes (BRASSINOSTEROID ENHANCED EXPRESSION1 (BEE1)) encoded a brassinosteroid enhanced expression transcription factor, while the other (G2-LIKE FLAVONOID REGULATOR (GFR)) encoded a G2-like flavonoid regulator. Phenylpropanoid-targeted analysis was performed using high-performance LC-MS, and gene expression analysis using quantitative reverse transcription-PCR. In both mutants, the accumulation of quercetins and scopolin was reduced under low-temperature growing conditions, whereas that of anthocyanin was increased. BEE1 and GFR were both shown to negatively regulate anthocyanin accumulation by inhibiting anthocyanin synthesis genes via the suppression of the bHLH (TRANSPARENT TESTA8 (TT8) and GLABROUS3 (GL3)) and/or the MYB (PRODUCTION OF ANTHOCYANIN PIGMENTS2 (PAP2)) components of the MBW complex. Our results provide new insight into the regulatory control of phenylpropanoid metabolism at low temperatures, and reveal that BEE1 and GFR act as important components of the signal transduction chain.

The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets

Two feeding experiments with female weaned piglets were carried out applying a complete two by two factorial design to investigate the effects of the dietary inclusion of 500 g/kg Fusarium toxin contaminated maize (8.6 mg/kg deoxynivalenol (DON); 1.2 mg/kg zearalenone (ZON)) and of 4 g/kg aluminosilicate (AS) as a detoxifying agent. The resulting four diets were fed ad libitum to a total of 80 piglets (20 piglets per group, allotted to a total of 20 pens) covering a live weight range of 10.5 +/- 1.3 to 27.5 +/- 4.4 kg in experiment 1, and to a total of 48 piglets (12 piglets per group, allotted to 12 pens) covering a live weight range of 9.7 +/- 1.8 to 21.4 +/- 4.8 kg in experiment 2. The animals of experiment 1 were slaughtered on days 34-36 of feeding the experimental diets. The mycotoxin analyses revealed that the control maize also contained considerable concentrations of Fusarium toxins, but the differences in DON and ZON concentrations between control and contaminated diets were sufficiently high to demonstrate both dose-related toxin effects. Voluntary feed intake and live weight gain of the animals were significantly reduced by the inclusion of Fusarium toxin contaminated maize into the diets in both experiments, while a significantly decreased feed to gain ratio was found in experiment 1. Furthermore, the relative weight of the uterus, stomach and heart of the animals fed the contaminated maize containing diets were significantly increased. Serum albumin concentrations and the activity of GLDH were significantly reduced by the inclusion of the contaminated maize. The addition of AS to the Fusarium toxin contaminated diets did not prevent or alleviate any of the mentioned effects. Moreover, the feed intake tended to be decreased by this supplementation in both experiments, while a significantly decreased feed to gain ratio was indicated for this factor in experiment one as well. The serum concentration of albumin and the activities of ASAT and gammaGT were significantly increased if AS was present in the diets while serum concentration of cholesterol and alpha-tocopherol were decreased significantly or in tendency, respectively. The concentrations of retinol and retinyl esters in liver and serum were not altered by the treatments. The analysed concentrations of zearalenone (ZON) and its metabolites in the bile fluid clearly indicated the differences in dietary ZON concentrations and showed that AS was ineffective in preventing the absorption of the toxin from the gastrointestinal tract. Also, serum concentrations of DON reflected the DON intake prior to sampling. However, there were no differences between groups fed diets with or without AS which also suggests the inefficacy of the tested AS in preventing the DON absorption. The present investigations failed to demonstrate a detoxifying capacity of the tested additive and emphasize the general necessity for a critical verification of detoxifying agents in vivo.

In vitro studies on the evaluation of mycotoxin detoxifying agents for their efficacy on deoxynivalenol and zearalenone

A simple in vitro system was developed to study the efficacy of commercially available mycotoxin detoxifying agents and adsorbing substances as feed additives to detoxify deoxynivalenol (DON) and zearalenone (ZON) in situ. The in vitro model simulates the conditions (pH, temperature and transit time) of the porcine gastrointestinal tract, as pigs react most sensitively to these mycotoxins. The commercially available products were not effective in detoxifying DON and ZON under the applied conditions, while activated carbon was able to bind both toxins and cholestyramine, and a modified aluminosilicate showed good adsorption abilities for ZON. Data obtained in dose dependency studies showed an estimated adsorption capacity of cholestyramine and the modified aluminosilicate of 11.7 and 5.7 g ZON/kg detoxifying agent. The in vitro system deployed in the present study was demonstrated to be a simple, helpful tool in screening substances for their ability to detoxify DON and ZON under the simulated conditions of the porcine gastrointestinal tract. Nonetheless in vivo experiments are indispensable to proof the efficacy.

In vivo detoxification of Fusarium toxins

Fusarium toxins are of great practical relevance in animal feeding since they may occur in toxicologically relevant concentrations. Therefore, many attempts have been made to find ways to detoxify contaminated feedstuffs or diets in order to cope with the problem. The supplementation of contaminated diets with detoxifying agents seems to be easily feasible, and in vitro results seem to be convincing. According to the Guideline 87/153/EEC of the Council of the European Communities, efficacy has to be proven by using an experimental design justified by the claims for use of the additive. In a review of the literature, only a few studies investigated specific parameters that could clearly reflect the claimed mode of action of the additives, and those demonstrated no measurable detoxifying effects. The majority of investigations focused on rather non-specific performance parameters, while many of these applied incomplete experimental designs. Nevertheless, most of the experiments did not demonstrate preventive effects. It is concluded that testing of currently available detoxifying agents did not follow the Council Directive in style and since the claim for their use was not proven. The application of complete two by two factorial experimental designs, the investigation of mycotoxins and/or metabolites in physiological samples as specific parameters and the verification of the specificity of the detoxifying agent is recommended for future in vivo investigations.

Accumulation of the coumarin scopolin under abiotic stress conditions is mediated by the Arabidopsis thaliana THO/TREX complex

Secondary metabolites are involved in the plant stress response. Among these are scopolin and its active form scopoletin, which are coumarin derivatives associated with reactive oxygen species scavenging and pathogen defence. Here we show that scopolin accumulation can be induced in the root by osmotic stress and in the leaf by low-temperature stress in Arabidopsis thaliana. A genetic screen for altered scopolin levels in A. thaliana revealed a mutant compromised in scopolin accumulation in response to stress; the lesion was present in a homologue of THO1 coding for a subunit of the THO/TREX complex. The THO/TREX complex contributes to RNA silencing, supposedly by trafficking precursors of small RNAs. Mutants defective in THO, AGO1, SDS3 and RDR6 were impaired with respect to scopolin accumulation in response to stress, suggesting a mechanism based on RNA silencing such as the trans-acting small interfering RNA pathway, which requires THO/TREX function.

UHPLC-MS metabolome based classification of umbelliferous fruit taxa: a prospect for phyto-equivalency of its different accessions and in response to roasting

Herbs of the Umbelliferae family are popular spices valued worldwide for their many nutritional and health benefits. Herein, five chief umbelliferous fruits viz., cumin, fennel, anise, coriander and caraway were assessed for its secondary metabolites diversity along with compositional changes incurring upon roasting as analyzed via ultra-high performance liquid chromatography coupled to photodiode array and electrospray ionization mass detectors UHPLC-qToF/MS. A total of 186 metabolites were annotated, according to metabolomics society guidelines, belonging mainly to flavonoids, fatty acids and phenolic acids. Multivariate models viz., PCA, HCA and OPLS-DA were further employed to assess fruits' heterogeneity in an untargeted manner and determine mechanistic changes in bioactive makeup post roasting viz., glycosidic cleavage, lipid degradation and Maillard reaction. Finally, the fruits' antioxidant activity showed decline upon roasting and in correlation with its total phenolic content. This study presents the first complete map of umbelliferous fruit metabolome, compositional differences and its roasting effect.

First metabolome map for umbelliferous fruits secondary metabolites profiling via UHPLC-QToF/MS with scrutinizing its metabolome compositional changes incurred upon roasting.

A substrate of the ABC transporter PEN3 stimulates bacterial flagellin (flg22)-induced callose deposition in Arabidopsis thaliana

Nonhost resistance of Arabidopsis thaliana against Phytophthora infestans, a filamentous eukaryotic microbe and the causal agent of potato late blight, is based on a multilayered defense system. Arabidopsis thaliana controls pathogen entry through the penetration-resistance genes PEN2 and PEN3, encoding an atypical myrosinase and an ABC transporter, respectively, required for synthesis and export of unknown indole compounds. To identify pathogen-elicited leaf surface metabolites and further unravel nonhost resistance in Arabidopsis, we performed untargeted metabolite profiling by incubating a P. infestans zoospore suspension on leaves of WT or pen3 mutant Arabidopsis plants. Among the plant-secreted metabolites, 4-methoxyindol-3-yl-methanol and S-(4-methoxy-indol-3-yl-methyl) cysteine were detected in spore suspensions recollected from WT plants, but at reduced levels from the pen3 mutant plants. In both whole-cell and microsome-based assays, 4-methoxyindol-3-yl-methanol was transported in a PEN3-dependent manner, suggesting that this compound is a PEN3 substrate. The syntheses of both compounds were dependent on functional PEN2 and phytochelatin synthase 1. None of these compounds inhibited mycelial growth of P. infestans in vitro Of note, exogenous application of 4-methoxyindol-3-yl methanol slightly elevated cytosolic Ca²⁺ levels and enhanced callose deposition in hydathodes of seedlings treated with a bacterial pathogen-associated molecular pattern (PAMP), flagellin (flg22). Loss of flg22-induced callose deposition in leaves of pen3 seedlings was partially reverted by the addition of 4-methoxyindol-3-yl methanol. In conclusion, we have identified a specific indole compound that is a substrate for PEN3 and contributes to the plant defense response against microbial pathogens.

Comparative Metabolite Fingerprinting of Four Different Cinnamon Species Analyzed via UPLC-MS and GC-MS and Chemometric Tools

The present study aimed to assess metabolites heterogeneity among four major Cinnamomum species, including true cinnamon (Cinnamomum verum) and less explored species (C. cassia, C. iners, and C. tamala). UPLC-MS led to the annotation of 74 secondary metabolites belonging to different classes, including phenolic acids, tannins, flavonoids, and lignans. A new proanthocyanidin was identified for the first time in C. tamala, along with several glycosylated flavonoid and dicarboxylic fatty acids reported for the first time in cinnamon. Multivariate data analyses revealed, for cinnamates, an abundance in C. verum versus procyandins, dihydro-coumaroylglycosides, and coumarin in C. cassia. A total of 51 primary metabolites were detected using GC-MS analysis encompassing different classes, viz. sugars, fatty acids, and sugar alcohols, with true cinnamon from Malaysia suggested as a good sugar source for diabetic patients. Glycerol in C. tamala, erythritol in C. iners, and glucose and fructose in C. verum from Malaysia were major metabolites contributing to the discrimination among species.

Non-invasive Presymptomatic Detection of Cercospora beticola Infection and Identification of Early Metabolic Responses in Sugar Beet

Cercospora beticola is an economically significant fungal pathogen of sugar beet, and is the causative pathogen of Cercospora leaf spot. Selected host genotypes with contrasting degree of susceptibility to the disease have been exploited to characterize the patterns of metabolite responses to fungal infection, and to devise a pre-symptomatic, non-invasive method of detecting the presence of the pathogen. Sugar beet genotypes were analyzed for metabolite profiles and hyperspectral signatures. Correlation of data matrices from both approaches facilitated identification of candidates for metabolic markers. Hyperspectral imaging was highly predictive with a classification accuracy of 98.5-99.9% in detecting C. beticola. Metabolite analysis revealed metabolites altered by the host as part of a successful defense response: these were L-DOPA, 12-hydroxyjasmonic acid 12-O-β-D-glucoside, pantothenic acid, and 5-O-feruloylquinic acid. The accumulation of glucosylvitexin in the resistant cultivar suggests it acts as a constitutively produced protectant. The study establishes a proof-of-concept for an unbiased, presymptomatic and non-invasive detection system for the presence of C. beticola. The test needs to be validated with a larger set of genotypes, to be scalable to the level of a crop improvement program, aiming to speed up the selection for resistant cultivars of sugar beet. Untargeted metabolic profiling is a valuable tool to identify metabolites which correlate with hyperspectral data.

The effect of increasing concentrations ofFusariumtoxins in piglet diets on histological parameters of the uterus and vagina

The effects of feeding diets containing 0.01, 0.06, 0.15, 0.22 and 0.42 mg zearalenone and 0.2, 0.8, 1.0, 1.9 and 3.9 mg deoxynivalenol per kg, originating from Fusarium toxin contaminated maize, on the uterus of 50 prepubertal piglets (10 pigs per treatment; BW 32.6+/-5.4 kg; approximately 70 days of age) were investigated. The mean weight of the uteri of animals receiving the most highly contaminated diet was significantly increased at the time of slaughtering. The histological investigation showed no marked differences between the feeding groups. Histometrical parameters of the surface epithelium of the uterus, of the uterine glands and the vaginal epithelium were not altered by the treatment.

Effects of conjugated linoleic acids fed to dairy cows during early gestation on hematological, immunological, and metabolic characteristics of cows and their calves

The aim of the present experiment was to test the stimulation ability of peripheral blood mononuclear cells (PBMC) expressed as stimulation index (SI) of newborn calves and of their dams fed a control fat supplement (CON, n=6) or 50 and 100g/d of a CLA-containing fat supplement (CLA50, n=5, and CLA100, n=6, respectively) during the preceding lactation period for 182 d after calving. The total intake of cis-9,trans-11 and trans-10,cis-12 CLA by groups CLA50 and CLA100 amounted to 4 and 8 g/d each, respectively. For this purpose, blood was collected immediately after parturition from calves before and after colostrum intake, and from cows after parturition and 21 d later. The SI was related to the fatty acid composition of erythrocyte and milk lipids and to various hematological and clinical-chemical parameters. Retrospective evaluation revealed that depletion time (i.e., the individual period elapsed between the day of terminating the feeding of the experimental diet in the preceding lactation period and the day of calving) ranged from 190 to 262 d, which corresponded to fetal exposure times of 19 to 102 d. The SI from cows increased significantly by 77 and 55%, within 21 d after calving according to the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and Alamar Blue assays, respectively. However, feeding of 50 g of the CLA product failed to demonstrate this increase in the MTT assay. Moreover, SI was significantly lower for calves whose dams belonged to the CLA50 group, whereas stimulation ability was comparable for the PBMC from calves whose mothers were treated with CON and CLA100. Plasma metabolites (total bilirubin, total cholesterol, glucose, nonesterified fatty acids, 3-β-hydroxybutyrate, total protein, and albumin) and hematological parameters (hematocrit, white blood cell profile) were not significantly influenced by dietary treatments of the cows in the preceding lactation period. Although the fatty acid pattern of erythrocyte lipids of cows remained uninfluenced, that of calves showed alterations due to the feeding type of their dams. For example, C16:0 increased significantly from 14.4 to 16.9% of total fatty acid methyl esters, whereas cis-9,trans-11 CLA increased slightly from 0.11 to 0.15% at the same time in calves when their mothers were fed the CLA100 instead of the CON diet. Fatty acid profile of colostrum was significantly different from that of milk after 3 wk for most of the detected fatty acids, but was not influenced by diet type. In conclusion, feeding a CLA-containing fat supplement during the preceding lactation and gestation period exerted effects on the stimulation ability of PBMC from cows and calves for the subsequent parturition. However, CLA dose effects were inconsistent and require further investigation.

Semi-polar root exudates in natural grassland communities

In the rhizosphere, plants are exposed to a multitude of different biotic and abiotic factors, to which they respond by exuding a wide range of secondary root metabolites. So far, it has been unknown to which degree root exudate composition is species-specific and is affected by land use, the local impact and local neighborhood under field conditions. In this study, root exudates of 10 common grassland species were analyzed, each five of forbs and grasses, in the German Biodiversity Exploratories using a combined phytometer and untargeted liquid chromatography-mass spectrometry (LC-MS) approach. Redundancy analysis and hierarchical clustering revealed a large set of semi-polar metabolites common to all species in addition to species-specific metabolites. Chemical richness and exudate composition revealed that forbs, such as Plantago lanceolata and Galium species, exuded more species-specific metabolites than grasses. Grasses instead were primarily affected by environmental conditions. In both forbs and grasses, plant functional traits had only a minor impact on plant root exudation patterns. Overall, our results demonstrate the feasibility of obtaining and untargeted profiling of semi-polar metabolites under field condition and allow a deeper view in the exudation of plants in a natural grassland community.

Tissue-specific signatures of metabolites and proteins in asparagus roots and exudates

Comprehensive untargeted and targeted analysis of root exudate composition has advanced our understanding of rhizosphere processes. However, little is known about exudate spatial distribution and regulation. We studied the specific metabolite signatures of asparagus root exudates, root outer (epidermis and exodermis), and root inner tissues (cortex and vasculature). The greatest differences were found between exudates and root tissues. In total, 263 non-redundant metabolites were identified as significantly differentially abundant between the three root fractions, with the majority being enriched in the root exudate and/or outer tissue and annotated as 'lipids and lipid-like molecules' or 'phenylpropanoids and polyketides'. Spatial distribution was verified for three selected compounds using MALDI-TOF mass spectrometry imaging. Tissue-specific proteome analysis related root tissue-specific metabolite distributions and rhizodeposition with underlying biosynthetic pathways and transport mechanisms. The proteomes of root outer and inner tissues were spatially very distinct, in agreement with the fundamental differences between their functions and structures. According to KEGG pathway analysis, the outer tissue proteome was characterized by a high abundance of proteins related to 'lipid metabolism', 'biosynthesis of other secondary metabolites' and 'transport and catabolism', reflecting its main functions of providing a hydrophobic barrier, secreting secondary metabolites, and mediating water and nutrient uptake. Proteins more abundant in the inner tissue related to 'transcription', 'translation' and 'folding, sorting and degradation', in accord with the high activity of cortical and vasculature cell layers in growth- and development-related processes. In summary, asparagus root fractions accumulate specific metabolites. This expands our knowledge of tissue-specific plant cell function.

Fusarium mycotoxins in conventionally and organically grown grain from Thuringia/Germany

Thefusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZON) were determined in conventionally and organically grown grain harvested 1998 in Thuringia/Germany. A total of 196 wheat samples and 69 rye samples was analysed.In this year with heavy rainfalls during the summer months, high concentrations offusarium mycotoxins were typical in grain grown in Germany, as the DON concentrations found here. DON concentrations in conventionally grown wheat were found to be significantly higher than in organically grown wheat. 69% of the conventionally grown wheat were tested positive, containing a mean concentration of 1540 µg/kg DM. In 54% of the organically grown wheat samples DON was detected with a mean value of 760 µg/kg DM. DON concentration in rye and ZON concentration in wheat showed similar tendencies.The different cultivars of conventionally grown wheat showed large differences in DON contamination.

Zur Beurteilung des Vorkommens der Fusarium-Toxine Deoxynivalenol (DON) und Zearalenon (ZON) sowie ihrer Metaboliten in physiologischen Substraten des Schweins

Gegenstand und Ziel: Die Untersuchung des Blutes und der Galle vom Schwein auf Rückstände der Fusarium- Toxine Deoxynivalenol (DON) und Zearalenon (ZON) sowie deren Metaboliten wird häufig zum Nachweis einer Belastung von Schweinen mit diesen Toxinen herangezogen. Die Einschätzung der klinischen Relevanz solcher Befunde wird in der Praxis kontrovers diskutiert. Das Ziel der vorliegenden Literaturübersicht bestand daher darin, all jene Faktoren zu diskutieren, die eine kritische Interpretation von Toxinrückstandsbefunden erleichtern. Material und Methoden: Im Einzelnen wurde die Konzentration von DON und ZON im Futter – unter besonderer Berücksichtigung von kritischen Konzentrationen sowie von Hintergrundbelastungen – den jeweiligen Konzentrationen der Toxinrückstände in den physiologischen Substraten gegenübergestellt. Hierzu wurde eine Reihe von Dosis-Wirkungs-Studien an Ferkeln, Mastschweinen sowie Sauen ausgewertet. Aspekte der Toxinkinetik sowie der Analytik wurden im Hinblick auf die Interpretation der Analysenbefunde sowie der Möglichkeiten der Ableitung von Grenzwerten für DON und ZON im Blut und in der Galle kritisch diskutiert. Schlussfolgerungen: Die Analytik des Futters auf beide Toxine liefert häufig eine bessere Grundlage zur Beurteilung der Toxinbelastung der Schweine, wenn eine sichere Zuordnung des Futters gewährleistet ist. Die Futteranalytik besitzt somit auch eine große prophylaktische Bedeutung bei der Überwachung des Futtermittelhygienestatus zur Vermeidung von Intoxikationserscheinungen durch DON und ZON. Klinische Relevanz: Positive Nachweise von DON im Blut und von ZON in der Galle sind zur Beurteilung einer kritischen Belastung von Schweinen über das Futter nur sehr begrenzt geeignet.

Fusarium toxin residues in physiological samples of piglets

Physiological samples of 100 piglets fed diets containing 0.01, 0.06, 0.15, 0.22 and 0.42 mg ZON and 0.2, 0.8, 1.0, 1.9 and 3.9 mg DON per kg over a period of 35±1.5 days were investigated for concentrations of deoxynivalenol (DON) and zearalenone (ZON) and their metabolites.DON was detected in serum, bile and urine in increasing concentrations corresponding to the diet contamination. The metabolite de-epoxy-DON was detected only in urine. The DON contamination of the diet was closely reflected by the serum concentrations of the piglets.ZON and its metabolite α-zearalenol were detected in bile fluid, liver and urine, while β-zearalenol was only detected in bile fluid. In serum neither ZON nor its metabolites were found. The total concentration of ZON plus its metabolites in the bile fluid corresponded well with the dietary contamination.For all analyses it has to be noted that toxin residues were detectable even in individual samples of piglets fed the control diet containing 0.01 mg ZON/kg and 0.2 mg DON/kg.