Accumulation and distribution of Zn and Mn in soybean seeds after nutrient seed priming and its contribution to plant growth under Zn- and Mn-deficient conditions

Nutrient seed priming is a strategy to increase the seed reserves of mineral nutrients as primary source for mineral nutrition during seedling development and early growth. The present study investigates the effects of zinc (Zn) and manganese (Mn) seed priming on growth and nutritional status of soybean under conditions of Zn and Mn limitation. Nutrient seed priming increased the natural seed reserves for Zn by, approximately, sixfold and by fivefold for Mn; however, 40–60% of the primed nutrients were adsorbed to the seed coat. Zinc seed priming was able to maintain plant growth for 5 weeks in the same way as Zn supply via the nutrient solution. It is concluded that nutrient seed priming offers perspectives to improve seed quality of soybean for early seedling development under limited nutrient supply or availability and needs further investigation on performance under various stress conditions.     

Sample pooling for real-time PCR detection and virulence determination of the footrot pathogen <Emphasis Type="Italic">Dichelobacter nodosus</Emphasis>

Dichelobacter nodosus is the principal cause of ovine footrot and strain virulence is an important factor in disease severity. Therefore, detection and virulence determination of D. nodosus is important for proper diagnosis of the disease. Today this is possible by real-time PCR analysis. Analysis of large numbers of samples is costly and laborious; therefore, pooling of individual samples is common in surveillance programs. However, pooling can reduce the sensitivity of the method. The aim of this study was to develop a pooling method for real-time PCR analysis that would allow sensitive detection and simultaneous virulence determination of D. nodosus. A total of 225 sheep from 17 flocks were sampled using ESwabs within the Swedish Footrot Control Program in 2014. Samples were first analysed individually and then in pools of five by real-time PCR assays targeting the 16S rRNA and aprV2/B2 genes of D. nodosus. Each pool consisted of four negative and one positive D. nodosus samples with varying amounts of the bacterium. In the individual analysis, 61 (27.1%) samples were positive in the 16S rRNA and the aprV2/B2 PCR assays and 164 (72.9%) samples were negative. All samples positive in the aprV2/B2 PCR-assay were of aprB2 variant. The pooled analysis showed that all 41 pools were also positive for D. nodosus 16S rRNA and the aprB2 variant. The diagnostic sensitivity for pooled and individual samples was therefore similar. Our method includes concentration of the bacteria before DNA-extraction. This may account for the maintenance of diagnostic sensitivity. Diagnostic sensitivity in the real-time PCR assays of the pooled samples were comparable to the sensitivity obtained for individually analysed samples. Even sub-clinical infections were able to be detected in the pooled PCR samples which is important for control of the disease. This method may therefore be implemented in footrot control programs where it can replace analysis of individual samples.     

Human guanylate-binding protein 1 as a model system investigated by several surface techniques

In medical technologies concerning the surface immobilization of proteins in a defined orientation, maintaining their activity is a critical aspect. Therefore, in this study, the authors have investigated the activity of an elongated protein attached to a self-assembled monolayer supported streptavidin layer for different relative orientations of the protein with regard to the surface. Several mutants of this protein, human guanylate-binding protein 1 (hGBP1) showing GTPase catalytic activity, have been furnished with either one or two biotin anchors. Various independent methods that are based on different biophysical properties such as surface plasmon resonance, atomic force microscopy, and quartz crystal microbalance have been used to determine the orientation of the hGBP1 variants after anchoring them via a streptavidin-linker to a biotinylated surface. The activity of guanosine-triphosphate hydrolysis of hGBP1 monomers bound on the surface is found to depend on their orientation relative to the substrate, relating to their ability to form dimers with other neighboring anchored mutants; the maximum activity is lower than that observed in solutions, as might be expected from diffusion limitations at the solid/liquid interface on the one hand and prevention from homodimer formation due to immobilization on the other hand.     

Marine myxobacteria as a source of antibiotics--comparison of physiology, polyketide-type genes and antibiotic production of three new isolates of Enhygromyxa salina

Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1(T) as their closest homolog, displaying between 98% (SWB005) and 99% (SWB004 and SWB006) sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE).     

Epidemiology of dark leaf spot caused by Alternaria brassicicola and A. brassicae in organic seed production of cauliflower

In organic seed production of Brassica vegetables, infections by Alternaria brassicicola and A. brassicae can cause severe losses of yield and seed quality. Four field experiments with or without artificial inoculation with A. brassicicola were conducted in organically managed seed‐production crops of cauliflower cv. Opaal RZ in 2005 and 2006 in the Netherlands. The development of A. brassicicola and A. brassicae on pod tissues and developing seeds was followed and seed quality was assessed. Alternaria brassicicola was externally present on 1·2% of the seeds 14 days after flowering and observed internally within 4 weeks after flowering. In both seasons, seed colonization by the pathogen increased slowly until maturation but sharply increased during maturation. A similar pattern was found for the colonization of pod tissues by A. brassicicola as quantified by TaqMan‐PCR. The incidence of A. brassicicola on mature seeds reached 70–90%. Internal colonization was found for 62–80% of the seeds. External and internal seed colonization by A. brassicae was much lower, with incidences below 3%. The quality of harvested seeds was generally low, with less than 80% of seeds able to germinate. Seed quality was not affected by warm water treatments. It was concluded that A. brassicicola and A. brassicae have the potential to infect pods and seeds soon after flowering. For the production of high quality seeds, producers must prevent such early infections. Therefore, new control measures are needed for use in organic cropping systems.     

Microcyclic conidiogenesis in powdery mildews and its association with intracellular parasitism by <Emphasis Type="Italic">Ampelomyces</Emphasis>

Microcyclic conidiogenesis (MC), a process defined as the production of conidia on a spore without any, or only a minimal, involvement of hyphal growth, has recently been reported in a little known powdery mildew species, Oidium longipes. To investigate whether this was an isolated case or it is a more general phenomenon in powdery mildew fungi, germinating conidia of eight species of the Erysiphales were examined using light microscopy. The following species were included in this work: Erysiphe necator on grapevine, Blumeria graminis f. sp. hordei on barley, Podosphaera xanthii on cucumber, Erysiphe sp. on Ligustrum vulgare, O. longipes on Petunia x grandiflora, O. neolycopersici on tomato, Golovinomyces cichoracearum on Rudbeckia laciniata and Sawadaea sp. on Acer negundo. In all these species, up to 4% of the germinated conidia exhibited MC. Moreover, when colonies of E. necator and O. neolycopersici, on detached grapevine and tomato leaves, respectively, were treated with a conidial suspension of Ampelomyces, the intracellular pycnidia of these mycoparasites appeared in microcyclic conidiophores. This represents a yet undescribed method of accelerating asexual reproduction in this mycoparasite. In the life cycle of powdery mildews, the importance of MC is still not clear but it should be taken into consideration when conidial germination is studied on the host surface for purposes such as epidemiology or species identification.     

Seawater exposure effect on the fracture toughness of low-density woods/GRP sandwich systems

The effect of seawater exposure on the fracture toughness of balsa (Ochroma pyramidale L.) and end-grain balsa cores that are widely used in small-craft constructive members has been investigated experimentally in this study. The interfacial fracture toughness was determined using mode I cracked sandwich beam (CSB) tests. Additionally, the same tests were performed for poplar (Populus tremula L.), easily available because of its natural distribution along the coast of Turkey and more cost-effective than balsa and its derivatives, to see if it is a proper alternative. It was found that balsa and poplar cores that can be classified as low-density cores have much lower fracture toughness values than end-grain balsa cores. Additionally, there was a positive effect of seawater exposure on their fracture toughness as opposed to that of the end-grain core. From the aspect of fracture toughness, the poplar core can be considered much more reliable than the balsa core where delamination loads occur.     

Safety of a non-adjuvanted therapeutic vaccine for the treatment of feline dermatophytosis

The safety of a non-adjuvanted inactivated fungal vaccine for the treatment of dermatophytosis in cats was investigated in two studies: a controlled laboratory study, and a placebo-controlled double-blind field study with a cross-over design in Europe. In the laboratory study, two groups of 10 cats each were administered an intramuscular twofold overdose, followed by five single 1 ml doses, of either vaccine or control product at 14-day intervals. In the field study, cats were treated with three intramuscular injections of 1 ml vaccine administered at 14-day intervals, as recommended by the manufacturer. A total of 89 cats were enrolled in the field study and divided into two groups to receive either vaccine or placebo for the first three treatments, followed by the opposite product for the final three treatments. The cats enrolled in the two studies were 12 weeks of age or older, as recommended by the manufacturer. All the cats were monitored closely for possible injection site reactions, systemic reactions (including changes in rectal body temperature) and adverse events. The results from both studies showed no significant differences between the vaccinated cats and the control or placebo-treated cats with regard to local or systemic reactions. A few mild to moderate local reactions were noted, but these were evenly distributed between the vaccinated and placebo-treated cats and resolved within a few days. No severe or serious adverse events related to the vaccinations were observed.     

Slaughter findings feedback systems--its use for farms of origin?

Over a period of 22 months 13 official meat inspection authorities examined a number of 152 520 swine at an Austrian slaughterhouse for pathologic-anatomic changes (five parameters). Of those veterinarians whose reliability in the recording of findings was a given, the results were analysed by employing a mathematical model which assessed whether the activities of 25 attending veterinarians and 223 farmers actually lead to an improvement of animal health in their livestock. Mild pneumonia was registered in 14.5% of swine; no attending veterinarians had any influence whatsoever on the occurrence of this parameter. Farmers' activities improved animal health on two farms (0.9%), six farms of origin (2.69%) showed significantly lower findings than the average of all farms. Pleurisy was ascertained in 22% of all slaughter pigs. Through measures taken, four attending veterinarians (16%) caused a reduction of incidents, two works managers (0.9%) made worse, six farmers (2.69%) improved animal health of their live stock. Seven farmers (3.14%) showed significantly (p < 0.05) higher, 28 farms (12.6%) lower prevalence. Pericarditis affected 4.5% of the animals in question. On all farms of origin the condition of health remained unchanged by measures taken by veterinarians. On two farms (0.9%) the influence exercised by farmers led to a deterioration of the health of swine, six businesses (2.69%) showed higher, one (0.45%) lower prevalence than on average. 6.2% of swine showed white spots. Attending veterinarians did not influence this parameter at all. With preventive measures taken five farms (2.24%) showed less, three farms (1.35%) higher prevalence by the end of the 22 month term. Mange concerned 2.2% of all slaughter pigs. The activities of one veterinarian (4%) caused the number of incidents to double; on six farms (2.69%) a significantly higher prevalence was registered. Whatever influence exercised, the status of health of slaughter pigs remained unchanged throughout the duration of the study.     

Pathogenicity determinants in smut fungi revealed by genome comparison

Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.