Detection of a chitinase-like protein in the roots of Douglas-fir trees infected with Armillaria ostoyae and Phellinus weirii

Protein was extracted from root bark of 11- and 25-year-old interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees that were naturally infected with Armillaria ostoyae (Romagnesi) Herink. The proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Root bark tissue adjacent to infected areas had a significantly higher protein concentration than healthy tissue (P < 0.05), whereas the protein concentration of infected tissue was consistently lower (P < 0.05) than that of healthy tissue. The SDS-PAGE profiles of healthy, infected, and adjacent-to-infected root bark tissues revealed significant differences in concentrations of a 29.3-kDa protein. The N-terminal amino acid sequence of the 29.3-kDa protein displayed significant homology (P = 0.013) to a basic endochitinase. Use of a polyclonal antibody raised against the 29.3-kDa putative endochitinase-like protein (ECP) indicated differences in the quantities of ECP in healthy roots compared with roots infected with A. ostoyae in 11- and 25-year-old interior Douglas-fir trees. The antibody was also used to screen for the presence of the 29.3-kDa protein in roots of 24-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) trees that were artificially inoculated with and colonized by Phellinus weirii (Murr.) Gilbn. The amount of ECP was elevated in root bark of coastal Douglas-fir in response to P. weirii infection, although in lower quantities relative to those found in the A. ostoyae-interior Douglas-fir pathosystem. The sequence homology of the ECP with a basic chitinase, together with its increased synthesis in response to two fungal pathogens, indicate a possible role for this protein in the defense of Douglas-fir against fungal pathogens.     

Wood ash use in forestry - a review of the environmental impacts

The use of wood fuel for energy production in the UK is setto increase in the near future as part of a government commitmentto increase renewable sources to 10 per cent by 2010. The ashgenerated as a by-product of combustion, whether for heat orpower generation, has potential use as a fertilizer in forestsystems. This review assesses the available information on factorsaffecting the quality of the ash and environmental implicationsarising from its application. The key determinants of wood ashchemistry are the tree species combusted, the nature of theburn process and the conditions at the application site. Woodash from hardwood species produces higher levels of macronutrientsin their ash than conifers, and the silica content is frequentlylower. A furnace temperature between 500 and 900°C is criticalto the retention of nutrients, particularly potassium, and determinesthe concentrations of potentially toxic metals including aluminiumin the ash. Fly ash, the lightest component that accumulatesin the flue system, can contain high concentrations of cadmium,copper, chromium, lead and arsenic and this ash should not beused as fertilizer. The form of the ash at application is important,with loose ash releasing Ca, K and Na more rapidly than granulatedash. Heavy metal, radionuclide and dioxin contamination of woodash-based fertilizers is minimal and unlikely to affect ecosystemfunction. The effects of wood ash are primarily governed byapplication rate and soil type. The benefits are maximized atlow dose rates, with possible toxicity from applications inexcess of 10 t ha^–1. For most forest sites, a single woodash application per rotation could replace all the nutrientslost after whole-tree harvesting (excepting N). Long-lastingpositive effects on tree growth have been observed on shallowpeats, in which the humus is slowly mineralized in responseto elevated pH and increased nutrient availability. In contrast,wood ash application to podzols is only effective in enhancingtree growth when nitrogen availability is non-limiting. To date,published research of wood ash effects on trees growing in claysand loams is minimal. A lag time for positive tree responsesto wood ash application is often observed, and may be the resultof phosphorous limitation at higher soil pH. The greatest reportedadverse ecological effects are to acidophilic ecosystems, particularlythe constituent bryophyte, soil bacteria and ectomycorrhizalcommunities.     

Absolute dating of Caribbean cores p6304-8 and p6304-9

Two deep-sea cores from the central Caribbean have been dated by the thorium-230/ protactinium-231 method. The ages obtained are in agreement with the ages previously obtained from other deep-sea cores from the same area. Because of their greater precision, the new dates provide a more accurate time scale for the past 170,000 years.     

Effect of the choice of food composition table on nutrient estimates: a comparison between the British and American (Chilean) tables

Objective: To determine the level of agreement between the American (Chilean) and British food composition tables in estimating intakes of macronutrients and antioxidants. DESIGN, SETTING AND SUBJECTS: Information based on a food-frequency questionnaire with emphasis on antioxidants was collected from 95 Chileans aged 24-28 years. Nutritional composition was analysed using the British table of food composition and the American table of food composition modified by Chilean food items. Mean differences and limits of agreement (LOAs) of estimated intake were assessed. RESULTS: Mean differences between the two tables of food composition ranged from 5.3% to 8.9% higher estimates when using the American (Chilean) table for macronutrients. For micronutrients, a bias towards a higher mean was observed for vitamin E, iron and magnesium when the American (Chilean) table was used, but the opposite was observed for vitamin A and selenium. The intra-class correlation coefficient (ICC) ranged from 0.86 (95% confidence interval (CI) 0.81-0.91) to 0.998 (95% CI 0.995-1.00), indicating high to excellent agreement. LOAs for macronutrients and vitamins A and C were satisfactory, as they were sufficiently narrow. There was more uncertainty for other micronutrients. CONCLUSION: The American table gives relative overestimates of macronutrients in comparison to the British table, but the relative biases for micronutrients are inconsistent. Estimates of agreement between the two food composition tables provide reassurance that results are interchangeable for the majority of nutrients.     

Gene Cloning and Tissue Expression Analysis of a PR-5 Thaumatin-Like Protein in Phellinus weirii-Infected Douglas-Fir

ABSTRACT In western North America, Douglas-fir (Pseudotsuga menziesii) is the most economically important conifer species susceptible to laminated root rot caused by Phellinus weirii. While attempting to internally sequence an endochitinase found to be up-regulated in P. weirii-infected Douglas-fir roots, we obtained overlapping peptide fragments showing 28% similarity with a PR-5 thaumatin-like protein (TLP) designated PmTLP (Pm for Pseudotsuga menziesi). A rabbit polyclonal antibody was reared against a synthetic peptide composed of a 29-amino-acid-long, conserved, internal sequence of PmTLP and purified by immunoaffinity. Western immunoblot analysis of infected roots of 24-year-old coastalfir showed significantly higher amounts of PmTLP (P < 0.01) closest to the point of P. weirii inoculation and infection than in uninfected regions of the same root. The antibody was also used to screen for PmTLP in roots of 25-year-old interior Douglas-firs naturally infected with a related pathogen, Armillaria ostoyae, and results showed significantly higher levels of PmTLP in bark tissues adjacent to infection (P < 0.05) than in uninfected tissue. Using polymerase chain reaction (PCR)-based cloning, the cDNA of PmTLP was shown to have a 702-bp open reading frame with a signal peptide cleavage site at 155 bp corresponding to a 29-amino-acid-long residue prior to the start of the N-terminal. Based on the deduced amino acid sequence, the molecular mass of the putative PmTLP was calculated to be 21.0 kDa with an isoelectric point of 3.71. Alignment analysis of PmTLP cDNA with a representative genomic DNA PCR sequence showed presence of one intron of variable size, within the coding region. The induction of PmTLP at the site of root infection and its presence in needle tissue suggests a general role for this protein in adaptation to stress and may be part of an integrated defense response initiated by the host to impede further pathogen spread.     

Ventricular rate control using a novel vagus nerve stimulating system in a dog with chronic atrial fibrillation

A 4-year-old, intact male Dogue de Bordeaux dog with congenital valvular pulmonic stenosis, tricuspid valve dysplasia, and chronic atrial fibrillation underwent ultrasound-guided balloon valvuloplasty in addition to pharmacological treatment. Owner compliance to prescribed pharmacotherapy proved very poor, and concerns developed regarding the ability to successfully control heart rate and symptoms using drug therapy alone. These concerns were addressed by the implantation of a novel vagal stimulation system that was programmed to prevent a ventricular rate of >145 bpm. Consequently, post-operative ventricular response rate decreased from up to 250 to 140 bpm. Successful ventricular rate control was maintained for 291 days post-operatively, following which euthanasia was elected by the owner due to persistent right-sided congestive heart failure. To the authors' knowledge, this is the first report of successful continuous rate control using a vagal stimulating system in a closed-chest, client-owned dog with chronic atrial fibrillation secondary to spontaneously occurring organic heart disease.     

Apple peels, from seven cultivars, have lipase-inhibitory activity and contain numerous ursenoic acids as identified by LC-ESI-QTOF-HRMS

Apple peel contains numerous phytochemicals, many of which show bioactivity. This study investigated the identity of triterpenoid compounds contained in ethanolic extracts of peel from seven apple cultivars. Using HPLC-ESI-QTOF-HRMS, accurate mass information was obtained for 43 compounds, and chemical identity was inferred from the calculated elemental composition, fragment masses, ms/ms, and a limited set of authentic standards. Compounds were identified as triterpene acids and tentatively identified as ursenoic (or oleanoic) acid derivatives containing hydroxyl, oxo, and coumaroyloxy groups. These apple skin extracts exhibited lipase-inhibitory activity, which may be linked to the ursenoic acid content. Furthermore, both triterpene content and lipase-inhibitory activity varied by cultivar.     

Natural Spawning of Captive Bigeye Scad Selar crumenophthalmus in Hawaii

Abstract.— Juvenile bigeye scad Selar crumenophthalmus were caught from the wild by hook and line and reared over 3 yr to establish a spawning broodstock of this species. The size at first maturity for captive males and females was 19-cm and 25-cm fork length (FL). Natural spawning of captive individuals occurred during the first year in captivity. The broodstock were observed to spawn repeatedly throughout their second and third years in culture. This species is a multiple spawner producing approximately 96 × 10³ to 121 × 10³ eggs/spawning group, 5 to 10 times per year. Stocking densities of 1–8 individuals/m³ were found to be suitable for natural spawning to occur. Collectively, the results indicate that this species exhibits notable potential for artificial propagation.