ROS and 9-oxylipins are correlated with deoxynivalenol accumulation in the germinating caryopses of Triticum aestivum after Fusarium graminearum infection

Wheat germinating caryopses may represent a starting point for the Fusarium Head Blight disease; however, only few studies concern the defence repertoire of wheat caryopses against fungal challenge. The germinating caryopses of two wheat commercial varieties (Blasco and Sagittario), differentially susceptible to FHB in the field, were inoculated with F. graminearum and the redox status in the interaction milieu, oxylipin production, the expression profile of some host-defence related genes, and programmed cell death in the aleuronic layer, were analysed. In Sagittario, the redox balance was profoundly modified and 9-oxylipins accumulated during fungal contamination. In this variety, F. graminearum produced a high quantity of deoxynivalenol whilst programmed cell death, also through metacaspases activation, was enhanced in the aleuronic layer of its caryopses. In Blasco, the expression of tolerance factors such as Pathogenesis-Related-protein1, glucosyl-transferase and glutathione transferase genes was up-regulated consequent to infection. Results show that unscavenged ROS and 9-oxylipins may be related to deoxynivalenol accumulation in the germinating caryopses of wheat after F. graminearum infection.     

Modifying land management in order to improve efficiency of rainwater use in the African highlands

Water scarcity and drought in Africa are often in the news. The widespread tendency to relate farmers’ notion of drought to changes in the occurrence of dry spells is misguided: several recent studies have yielded little evidence of an increase in the length and/or frequency of such spells. The farmers’ concept of drought is contextual and an indirect result of land degradation. Plant production suffers because water is not available due to deteriorated physical properties of soil. Farmers’ perception of drought refers to the Green Water Use Efficiency (GWUE), i.e. the fraction of rain that is used for plant transpiration. GWUE in Africa is remarkably low: in sub-Saharan Africa, only 15% of the terrestrial rainwater is used by plants for the production of food, fodder and fibre. Although a millet crop grown under traditional circumstances uses only 50 mm in transpiration, the crop frequently suffers from agricultural drought due to excessive losses of rainwater.A range of land management practices is available to help improve GWUE. They can be classified according to their function. Hedgerow barriers and terraces can mitigate runoff; infiltration rates below hedgerows in Kenya were found to be three to eight times higher than where the crop was grown. Mulch that triggers soil fauna can improve water availability; mulching with straw from a local perennial grass in Burkina Faso doubled the water use efficiency from 1 kg mm⁻¹ without fauna to 2 kg mm⁻¹ with fauna. Water harvesting and water–nutrient synergy can improve water use; in case permeable barriers combined with the use of compost Sorghum yield in Burkina Faso was 2.3 times higher than in the control plots and the plots with the barriers only.Green water deserves more attention from policy makers, planners, land users, water engineers and managers.     

Serum thyroxine concentrations in clinically healthy pet guinea pigs (Cavia porcellus)

Background: Guinea pigs (Cavia porcellus) are often presented as patients in veterinary practice. Nevertheless, only limited information is available about endocrine diseases or thyroxine reference values for the species. Objective: The aim of this study was to determine serum thyroxine concentrations in a well‐defined population of clinically healthy pet guinea pigs. Methods: Between October 2007 and July 2008, serum samples were collected from 40 clinically healthy guinea pigs of different sexes, ages, and breeds that were presented to our clinic for a general health check or for castration. Pregnant females were excluded from the study. Thyroxine concentration was measured using a chemiluminescence test (Immulite 2000 Canine Total T4). Results: Thyroxine concentrations ranged from 14.2 to 66.9 nmol/L (1.1–5.2 μg/dL) with a median value of 27.0 nmol/L (2.1 μg/dL). Females (n=16) had significantly (P=.039; Mann–Whitney U‐test) lower thyroxine values than castrated males (n=8), whereas no differences were found between females and intact males (n=16) or between intact and castrated males. No significant correlation was found between thyroxine concentration and age. Conclusion: This is the first report of serum thyroxine reference values for a well‐defined population of healthy pet guinea pigs as measured by a chemiluminescence assay. The results were higher than those previously reported for this species and emphasize the importance of using appropriate reference intervals for the diagnosis of hyperthyroidism.     

Soil organic matter dynamics and losses in manured maize-based forage systems

Soil organic matter (SOM) produces positive effects on multiple soil properties. Increasing its level also provides an opportunity to reduce atmospheric concentration of carbon dioxide (CO₂). Recycling animal manure and returning crop residue are among the main practices to enhance organic carbon (C) stock in arable croplands. This study analysed data of soil organic carbon (SOC) stocks from a medium-term field trial (established in 1992) through a Hénin–Dupuis-based equation to determine the proportion of different organic materials retained in the soil as SOM.The treatments included in the experiment simulated different typical management techniques and implied the application to the soil of various organic materials, i.e. cattle slurry, cattle farmyard manure, maize straw, root, maize and ley stubble. Soil organic carbon and total nitrogen (N) (Kjeldhal N) were measured in the 0–30 cm layer during spring 1999 and spring 2003. The relationship between SOC and N stocks measured in 1999 and 2003 and the annual additions of C and N was described by the Hénin–Dupuis-based equation, assuming the presence of two C and N pools (stable and fresh).Our results showed that the application of farmyard manure, slurry and maize straw induced higher C and N content compared to the application of urea without return of crop residue. The different levels of urea application did not produce any significant difference in C and N soil content.We found that approximately 2% of SOC is lost to the atmosphere annually. Furthermore, the amount of C and N retained in the soil each year varied by organic materials: 46% C and 44% N with farmyard manure, 26% C and 11% N with slurry, 28% C and 10% N with root and 6% C with maize straw and ley stubble.These results were used to inform an estimate of C lost or removed to/from atmosphere following manure application and crop residue return for the compilation of greenhouse gas inventories. We found that the most C conservative management is the production and spreading of farmyard manure and that increasing amounts of mineral N fertilizer did not affect the C sequestration extent.     

Enteroendocrine profile of α-transducin immunoreactive cells in the gastrointestinal tract of the European sea bass (Dicentrarchus labrax)

In vertebrates, chemosensitivity of nutrients occurs through the activation of taste receptors coupled with G-protein subunits, including α-transducin (G_αtran) and α-gustducin (G_αgust). This study was aimed at characterising the cells expressing G_αtran immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. G_αtran immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some G_αtran immunoreactive cells in the stomach contained G_αgust immunoreactivity. Gastric G_αtran immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, G_αtran immunopositive cells did not contain somatostatin, gastrin/cholecystokinin, glucagon-like peptide-1, substance P or calcitonin gene-related peptide immunoreactivity in any investigated segments of the sea bass gastrointestinal tract. Specificity of G_αtran and G_αgust antisera was determined by Western blot analysis, which identified two bands at the theoretical molecular weight of ~45 and ~40 kDa, respectively, in sea bass gut tissue as well as in positive tissue, and by immunoblocking with the respective peptide, which prevented immunostaining. The results of the present study provide a molecular and morphological basis for a role of taste-related molecules in chemosensing in the sea bass gastrointestinal tract.     

Naturally acidic waterways: conceptual food webs for better management and understanding of ecological functioning

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What is the evidence? The issue of verifying correct needle position during epidural anaesthesia in dogs

Objectives

To review the methods for verifying the needle position while performing epidural anaesthesia in dogs, and to discuss the advantages, disadvantages, usefulness and reliability of each technique in the experimental and clinical research setting.

IgE-Mediated Cross-Reactivity among Leguminous Seed Proteins in Peanut Allergic Children

The immunological cross-reactivity among major protein- and oil-crops, including lupin, lentil, pea, peanut, kidney bean and soybean, has been studied by a combination of in vitro and in vivo experimental approaches: SDS-PAGE separations of legume protein extracts and immuno-blot revelations with 12 peanut-sensitive subjects’ sera, Immuno-CAP and Skin Prick tests on the same subjects. The immuno-blotting data showed a wide range of IgE-binding responses both displayed by one subject towards different plant extracts and among subjects. Differences were both quantitative and qualitative. The prevalent responses of most subjects’ sera were seen with peanut polypeptides, as expected, as well as with various polypeptides of the other legumes, the most recurrent of which were the basic subunits of the 11S globulins. The distribution of in vivo responses generally paralleled those obtained by in vitro approaches with strong responses elicited by peanut, lentil and pea protein extracts, especially by most sensitive subjects, thus providing a consistent overall set of results. In this work, the comparison of various approaches has allowed us to get an overall broad picture of the immunological cross-reactivities among proteins of widely used different seed species and to hypothesize the role of most conserved specific polypeptides.