Pflanzenkrankheiten,die die Welt beweg(t)en     

Iris Sauer 《Erwerbs-Obstbau》2017,59(2):155-156

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Energy allocation in juvenile roach and burbot under different temperature and feeding regimes     

Binner M  Kloas W  Hardewig I 《Fish physiology and biochemistry》2008,34(2):103-116

Cold-active burbot (Lota lota (L.)) display reduced food intake during the summer. The impact of temperature on their energy budget was investigated in starved fish in a laboratory setting, simulating summer (20°C) and winter (4°C) conditions, to elucidate the impact of high temperature on burbot metabolism. Metabolic effects in burbot were compared to roach (Rutilus rutilus (L.)), which typically fast in winter. During warm acclimation, starvation (four weeks) resulted in a metabolic depression of oxygen consumption in both species. In roach, metabolic rate decreased by 55% after two weeks of starvation. Burbot, in contrast, displayed an immediate depression of metabolic rate by 50%. In both species, no reductions were observed in the cold. The temperature-induced differences between the metabolic rates at 20°C and 4°C showed a lower thermal sensitivity in burbot (Q ₁₀ = 1.9) compared to roach (Q ₁₀ = 2.7). Notably, for each species, energy consumption during starvation was highest under experimental conditions simulating their natural active periods, respectively. Warm acclimated roach relied mainly on muscle reserves, whereas in cold acclimated burbot, liver metabolic stores made a major contribution to the energy turnover. In cold acclimated roach and warm acclimated burbot, however, starvation apparently reduced swimming activity, resulting in considerable savings of energy reserves. These lower energy expenditures in roach and burbot corresponded to their natural inactive periods. Thus, starvation in burbot caused a lower energy turnover when exposed to high temperatures. These season-dependent adaptations of metabolism represent an advantageous strategy in burbot to manage winter temperature and withstand metabolism-activating summer temperatures, whereas roach metabolism correlates with the seasonal temperature cycle.  相似文献   

Priming of antimicrobial phenolics during induced resistance response towards Pectobacterium carotovorum in the ornamental monocot calla lily     

Luzzatto T  Golan A  Yishay M  Bilkis I  Ben-Ari J  Yedidia I 《Journal of agricultural and food chemistry》2007,55(25):10315-10322

Calla lilies are herbaceous monocotyledonous plants that are highly sensitive to Pectobacterium carotovorum, the causal agent of soft-rot disease. Results demonstrate that, in response to elicitation using plant defense activators, the calla lily produces elevated levels of antimicrobial phenolics and that these compounds contribute to increased resistance against P. carotovorum, as shown by reduced bacterial proliferation in elicited leaves. The polyphenolic nature of the induced compounds was supported by autofluorescence, absorbance spectra, and reaction with Folin-Ciocalteu reagent. Two plant defense activators, Bion and methyl jasmonate, differed in both their capacity to induce accumulation of polyphenols and their resistance against the pathogen. Methyl jasmonate elicitation brought about higher accumulation of free phenolics relative to Bion, suggesting priming of bioactive polyphenols as a principal factor in the calla lily defense against P. carotovorum. To further characterize the nature of induced compounds, two major compounds were collected and identified as swertisin and isovitexin by mass and nuclear magnetic resonance spectroscopies.  相似文献   

Piceid (resveratrol glucoside) synthesis in stilbene synthase transgenic apple fruit   总被引：5，自引：0，他引：5  

Rühmann S  Treutter D  Fritsche S  Briviba K  Szankowski I 《Journal of agricultural and food chemistry》2006,54(13):4633-4640

A stilbene synthase gene along with the selectable marker gene bar for herbicide resistance was transferred via Agrobacterium tumefaciens mediated transformation into apple (Malus domesticaBorkh.) cvs. 'Elstar' and 'Holsteiner Cox'. The stilbene synthase catalyzes the conversion of 1 molecule of p-coumaroyl-CoA and 3 molecules of malonyl-CoA into 3,4',5-trihydroxystilbene, commonly known as resveratrol. This phytoalexin has implications in both phytopathology and human health. Greenhouse-grown transgenic and nontransformed control plants were grafted onto dwarfing rootstock M27. Flowering and fruiting occurred within the following years, offering the opportunity to analyze transgenic apple fruit and fertility of transgenic plants as well as inheritance of the transgenes into the seedling progeny. Molecular analysis revealed that the stilbene synthase is expressed in transgenic plants and in the skin and flesh of transgenic apple fruit. After formation, resveratrol is modified by the addition of a hexose sugar. The resulting component was characterized as piceid. With the aim of characterizing the influence of the novel biosynthetic pathway on the accumulation of other phenolic compounds naturally present in apple fruit, the amounts of flavanols, flavonols, phloretin derivatives and hydroxycinnamic acids in wild type and transgenic fruit were determined by HPLC. In all investigated transformed lines that accumulated piceid, no negative correlation between levels of piceid and the above-mentioned compounds was observed, except for the flavonol contents, which slightly decreased. Inheritance of the transgenes was confirmed in the seedling progeny, which were obtained after pollination of transgenic plants with nontransgenic pollen and vice versa after pollination of nontransgenic plants with pollen obtained from transgenic plants. The fertility of stilbene synthase transgenic plants was demonstrated. To the authors' knowledge this is the first time that data are available on piceid synthesis in transgenic apple fruit and the effects of its accumulation on levels of other phenolic compounds present in the fruit.  相似文献   

Plasmodium blood parasite found in endangered Galapagos penguins (Spheniscus mendiculus)     

Iris I. Levin  Diana C. Outlaw  Patricia G. Parker 《Biological conservation》2009,142(12):3191-3195

This is the first report of a Plasmodium blood parasite found in the Galapagos Archipelago. Phylogenetic analyses place this parasite, recovered from endangered Galapagos penguins (Spheniscus mendiculus), within the genus Plasmodium, and suggest a close relationship to some of the most dangerous lineages of Plasmodium that have been known to cause severe mortality and morbidity in captive penguin populations. Infectious disease is an increasingly important cause of global species extinctions, and extinctions due to avian pox and avian malaria (Plasmodium relictum) have been well documented in Hawaiian avifauna. Plasmodium blood parasites had not been detected in Galapagos birds until now, despite previous microscopic and molecular screening of many of the species, including the Galapagos penguin. While penguin populations now appear healthy, it is unclear whether this parasite will have an obvious impact on their survival and reproduction, particularly during El Niño events, which cause stress due to reduced food availability. It is possible that this parasite arrived with or shortly after the recent arrival of an introduced mosquito, Culex quinquefasciatus, known elsewhere as a competent vector of Plasmodium blood parasites.  相似文献   

Performance and digestibility of growing sheep fed with a?ai seed meal-based diets     

Gomes DI  Véras RM  Alves KS  Detmann E  Oliveira LR  Mezzomo R  Dos Santos RB  de Sousa Barcelos S 《Tropical animal health and production》2012,44(7):1751-1757

This trial was conducted to assess the efficacy of a?ai seeds in the diet of sheep, specifically, to evaluate the intake, digestibility, and weight gain in sheep that are fed with diets containing four different mixtures of a?ai seeds and coastcross hay. Sixteen noncastrated male sheep with an average initial body weight of 22?kg were randomly assigned to one of four diet treatments using initial body weight as a covariate. The diets used coastcross hay as the basal roughage in a 60:40 roughage/concentrate ratio. The concentrate was the same in all the treatments. The a?ai seed was added to the diet as a partial substitute for the coastcross hay to make up four diet treatments: 0 (control), 5, 10, and 15?% a?aí added to the diet on a dry matter basis. The daily weight gain, final body weight, and feed intake were found to linearly increase with the increase in added dietary a?ai seed meal (P?相似文献   

Recombinant Angiotensin-Converting Enzyme 2 Suppresses Pulmonary Vasoconstriction in Acute Hypoxia     

Axel Kleinsasser  Iris Pircher  Benedict Treml  Martin Schwienbacher  Manfred Schuster  Eveline Janzek  Hans Loibner  Josef M. Penninger  Alex Loeckinger 《The Forestry Chronicle》2012,23(1):24-30

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Characterisation and categorisation of the diversity in viscoelastic vibrational properties between 98 wood types     

Iris Brémaud  Yves El Kaïm  Daniel Guibal  Kazuya Minato  Bernard Thibaut  Joseph Gril 《Annals of Forest Science》2012,69(3):373-386

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Increased knowledge on diversity in wood properties would have implications both for fundamental research and for promoting a diversification of uses as material.  相似文献   

Selection of food items for inclusion in a newly developed food-frequency questionnaire     

Shai I  Shahar DR  Vardi H  Fraser D 《Public health nutrition》2004,7(6):745-749

OBJECTIVES: To highlight the differences between the food list required in a food-frequency questionnaire (FFQ) to rank people by their intake and the food items that contribute to absolute intake, and to discuss possible applications. METHODS: We conducted a nutritional survey among 1173 adults using an adapted 24-hour recall questionnaire. STATISTICAL ANALYSIS: To develop an FFQ, we analysed the 24-hour recall survey data by performing a stepwise multiple regression after grouping conceptually similar food items into 175 food groups. RESULTS: In total, 126 food groups were included in the developed FFQ in order to explain at least 80% of the variance in the consumption of each of 27 nutrients. The nutrients that were explained by a few food groups were vitamin A (one food group), alcohol (two), beta-carotene (two), vitamin E (three) and cholesterol (five). Nutrients that were explained by a large number of food groups were energy (37 food groups), potassium (31), magnesium (31), dietary fibre (30), phosphorus (31) and sodium (29). Using energy intake as an example, soft drinks were the best between-person energy classifiers, while providing only 2.4% of the total energy intake. Wine, seeds and nuts, which contributed highly to the variance, were minor energy contributors. In contrast, milk, sugar, fried chicken/turkey breast or whole chicken/turkey, which explained little of the variation in the population, were major energy contributors. CONCLUSIONS: Developing an FFQ on the basis of common foods may not explain the between-person variation required for ranking individual intake in diet-disease studies. Producing lists of "discriminating items" can be a useful application in developing mini-FFQs for selected nutrients.  相似文献   

Modelling nitrate and bromide leaching from sewage sludge   总被引：2，自引：0，他引：2  

Iris Vogeler  Steve R. Green  Tessa Mills  Brent E. Clothier 《Soil & Tillage Research》2006,89(2):177-184

A deterministic model for assessing the risk of groundwater contamination by nitrate from land-based sludge disposal was evaluated. A controlled large-lysimeter experiment was set up to monitor movement of nitrate through soil. Four large lysimeters of 900 mm length were packed with Manawatu fine sandy loam (a Dystric Fluventric Eutrochrept), on top of which 200 mm of municipal sewage sludge was applied. One of the lysimeters was planted with pasture (Lolium perenne and Festuca arundacea), one with a willow tree (Salix sp. ‘Tongoio’), another with a poplar tree (Populus sp. ‘Kawa’), and one was left bare. Bromide was used as a conservative tracer. Movement of bromide and nitrate was analysed in the effluent from the base of the lysimeters.The processes of water and nutrient transport were modelled using a mechanistic scheme based on Richards’ equation for water transport and the convection–dispersion equation (CDE) for nutrient transport. These equations were both linked to a sink term for plant uptake. The model simulated well the transport of water and movement of bromide in the four different lysimeters. The agreement between measured and simulated nitrate leaching was also reasonable considering the simplified model. Uptake of nitrogen by trees reduced the quantity of nitrogen available for leaching. The model could aid development of sustainable management of land-based sewage sludge disposal in terms of nitrate leaching. The next step will be to further develop the model for heavy metal movement, as heavy metals are common co-contaminants of sewage sludge.  相似文献