European pome fruit genetic resources evaluated for disease resistance

Pome fruit genetic resources collections constitute a highly valuable resource not only for fruit breeding but also for direct use by nurseries, growers, and home gardeners. In order to use these resources efficiently and sustainably, reliable evaluation data on fruit and tree characteristics must be generated. Here we focus on pome fruit genetic resources evaluated phenotypically and genotypically for susceptibility to apple scab (Venturia inaequalis), powdery mildew (Podosphaera leucotricha), fire blight (Erwinia amylovora), pear rust (Gymnosporangium sabinae) and storage diseases (e.g., Penicillium expansum). Examples are presented of several ongoing projects throughout Europe, with the aim to evaluate fruit genetic resources for disease susceptibility and potential use in breeding and for commercial use. The COST action 864 has fostered international cooperation in the evaluation of pome fruit genetic resources, and some of these evaluations therefore involve research groups from several of the participating countries.     

Androgenesis-inducing stress treatments change phytohormone levels in anthers of three legume species (Fabaceae)

Legumes are recalcitrant to androgenesis and induction protocols were only recently developed for pea (Pisum sativum L.) and chickpea (Cicer arietinum L.), albeit with low regeneration frequencies. Androgenesis is thought to be mediated through abscisic acid (ABA) but other phytohormones, such as auxins, cytokinins, and gibberellins, have also been implicated. In view of improving induction protocols, the hormone content of pea, chickpea, and lentil anthers was measured after exposure to cold, centrifugation, electroporation, sonication, osmotic shock, or various combinations thereof using an analytical mass spectrometer. Indole-3-acetic acid (IAA) had a key function during the induction process. In pea, high concentrations of IAA-asparagine (IAA-Asp), a putative IAA metabolite, accumulated during the application of the different stresses. In chickpea, the IAA-Asp concentration increased 30-fold compared to pea but only during the osmotic shock treatment and likely as a result of the presence of exogenous IAA in the medium. In contrast, no treatment in lentil (Lens culinaris) invoked such an increase in IAA-Asp content. Of the various cytokinins monitored, only cis zeatin riboside increased after centrifugation and electroporation in pea and possibly chickpea. No bioactive gibberellins were detected in any species investigated, indicating that this hormone group is likely not linked to androgenesis in legumes. In contrast to the other stresses, osmotic shock treatment caused a reduction in the levels of all hormones analyzed, with the exception of IAA-Asp in chickpea. A short period of low hormone content might be a necessary transition phase for androgenesis induction of legumes. KEY MESSAGE: Five androgenesis-inducing stress treatments changed content of ABA, auxin and cytokinin in anthers of three legumes. Osmotic shock treatment differed because it reduced hormone content to very low levels.     

Management of a post-radiotherapy xerostomic patient--a case report

doi: 10.1111/j.1741‐2358.2011.00519.x Management of a post‐radiotherapy xerostomic patient – a case report Objective: The objective of the study was to fabricate complete denture with palatal reservoir filled with artificial saliva for a post radiotherapy edentulous patient. Background: Xerostomia is a subjective complaint rather than a disease. It is caused by irradiation, medication, Sjogren's syndrome & neurological factors such as stress. Radiotherapeutic treatment of head and neck cancer patients often causes long term dysfunction involving their salivary function, swallowing capabilities & taste. All three of these domains are affected by radiation‐ induced damage to the salivary glands. This in turn results in poor retention of complete denture, frequent trauma to alveolar ridge & other oral infections. All these events drastically affects quality of life of ageing patients. Material and Method: A complete denture in heat cure acrylic resin was fabricated in which a palatal reservoir was made on the palatal side. Results: Problems arising due to xerostomia were reduced to a great extent. Conclusion: Prosthodontic management of Xerostomic patient include several techniques. This paper presents a case report of post radiotherapy edentulous patient in which complete denture with palatal reservoir filled with artificial saliva was fabricated.     

Cross-relaxation bottleneck in water-lysozyme proton magnetization exchange

The proton spin-lattice relaxation parameters in natural and deuterated lysozyme solutions have been measured as a function of temperature (0-50 degrees C). The variation of the apparent magnitudes of the water proton magnetizations in the solutions with temperature indicates that magnetic coupling mixes protein and water proton magnetizations. The results are consistent with an exchange cross-relaxation model (Hills, B. P., Mol Phys 1992, 76, 489-508) in which the cross-relaxation acts between the labile and nonlabile protons, rather than between water and protein protons. Although this cross-relaxation pathway clearly affects the observed magnetization fractions in this protein solution, its influence on the relaxation rates is less apparent.     

Extension of the Nef reaction to C-glycosylnitromethanes

Acid-catalysed methanolysis of 3,4,5,6-tetra-O-acetyl-1,2-dideoxy-l-arabino-hex-1-enitol proceeds via a cascade set of consecutive reactions resulting in its regiospecific conversion to a mixture of alpha- and beta-C-L-arabinofuranosylmethanal dimethyl acetals and a mixed internal methyl acetal. Structures of the final products of the overall process provide unique evidence that a kinetically controlled, five-membered-ring closure precedes a six-membered-ring closure in reversible systems capable of giving both five-membered and six-membered all-sp3-atom rings. Determination of the reaction intermediate enabled extension of the Nef reaction to C-glycosylnitromethanes. Protonated aci-nitro forms of C-glycosylnitromethanes that are resistant to the Nef reaction in aqueous acidic media undergo a modified Nef reaction in acidified methanol, and the corresponding C-glycosylmethanal dimethyl acetals with alpha-L-arabinopyranosyl, beta-D-glucopyranosyl, beta-D-galactopyranosyl, beta-D-mannopyranosyl and beta-L-rhamnopyranosyl configurations were obtained in moderate yields.     

Preparation, single-crystal X-ray diffraction and high-resolution NMR spectroscopic analyses of N-[(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol)-5-yl]trimethylammonium iodide

The synthesis and isolation of 1,4-anhydro-5-deoxy-5-iodo-2,3-O-isopropylidene-D,L-ribitol and N-[(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol)-5-yl]trimethylammonium iodide are described. The products were examined by (1)H, (13)C NMR spectroscopy, and N-[(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol)-5-yl]trimethylammonium iodide was additionally analyzed by X-ray crystallography.     

Mutator phenotype of Caenorhabditis elegans DNA damage checkpoint mutants

DNA damage response proteins identify sites of DNA damage and signal to downstream effectors that orchestrate either apoptosis or arrest of the cell cycle and DNA repair. The C. elegans DNA damage response mutants mrt-2, hus-1, and clk-2(mn159) displayed 8- to 15-fold increases in the frequency of spontaneous mutation in their germlines. Many of these mutations were small- to medium-sized deletions, some of which had unusual sequences at their breakpoints such as purine-rich tracts or direct or inverted repeats. Although DNA-damage-induced apoptosis is abrogated in the mrt-2, hus-1, and clk-2 mutant backgrounds, lack of the apoptotic branch of the DNA damage response pathway in cep-1/p53, ced-3, and ced-4 mutants did not result in a Mutator phenotype. Thus, DNA damage checkpoint proteins suppress the frequency of mutation by ensuring that spontaneous DNA damage is accurately repaired in C. elegans germ cells. Although DNA damage response defects that predispose humans to cancer are known to result in large-scale chromosome aberrations, our results suggest that small- to medium-sized deletions may also play roles in the development of cancer.