267 research outputs found

    The endoplasmic reticulum in plant immunity and cell death

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    The endoplasmic reticulum (ER) is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane, or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programed cell death (PCD) in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signaling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants

    Growth versus immunity : a redirection of the cell cycle?

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    Diseases caused by plant pathogens significantly reduce growth and yield in agricultural crop production. Raising immunity in crops is therefore a major aim in breeding programs. However, efforts to enhance immunity are challenged by the occurrence of growth inhibition triggered by immunity that can be as detrimental as diseases. In this review, we will propose molecular models to explain the inhibitory growth-immunity crosstalk. We will briefly discuss why the resource reallocation model might not represent the driving force for the observed growth-immunity trade-offs. We suggest a model in which immunity redirects and initiates hormone signalling activities that can impair plant growth by antagonising cell cycle regulation and meristem activities

    Effekt von capsaicinhaltiger Creme auf die Mikrozirkulation der Haut

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    Hintergrund: Der dermale Blutfluss trägt in der Chirurgie massgeblich zu der Wundheilung sowie dem Überleben von Lappenplastiken bei. Die topische Applikation von Substanzen stellt eine einfache Form der Einflussnahme mit meist nur geringen Nebenwirkungen dar. Als Referenz für weitere Untersuchungen an Patienten und Lappenplastiken mit gestörtem Blutfluss werden in der vorliegenden Arbeit die durch Capsaicin hervorgerufenen Effekte der Durchblutungsänderung beschrieben. Methoden: In der vorliegenden Arbeit als Teil einer prospektiv, randomisiert, placebokontrolliert angelegten Doppelblindstudie wird der Effekt von topisch applizierter Finalgon® Creme mit dem Inhaltsstoff Capsaicin auf die Rückenhaut 46 gesunder Probanden zwischen 18 und 40 Jahren quantifiziert und mit dem durch Bepanthen® Creme hervorgerufenen Effekt, verglichen. Nach erfolgter Inkubation der Haut über 15min mit den Cremes wurde im Abstand von 15min über einen Zeitverlauf von 120min der Effekt derselben mittels O2C-Gerät die Sauerstoffsättigung, die relative Hämoglobinmenge, der Blutfluss und die Blutflussgeschwindigkeit in 2mm und 8mm Tiefe quantifiziert. Ergebnisse: Capsaicin bewirkte 30min nach Inkubation einen hoch signifikanten Anstieg der Sauerstoffsättigung der oberflächlichen und tiefen Messwerte. Ebenso kam es zu einem hoch signifikanten Anstieg des Blutflusses sowie der Blutflussgeschwindigkeit in beiden Messtiefen. In der oberflächlichen Messung fiel eine signifikante Erhöhung der relativen Hämoglobinmenge auf. Eine Hyperämie zeigte sich auch in den Messungen der Ausdehnung der lokalen Rötung der Haut, wobei die Hauttemperaturen unverändert blieben. Für die Messungen des Blutflusses und der Blutflussgeschwindigkeit zeigte sich nach 90 bis 120min ein Hinweis für ein Rebound Phänomen, welches bislang in der Literatur noch unbeschrieben blieb. Diskussion: Die Studie ermöglicht, mittels der nicht invasiven und gut reproduziertbaren Messmethode des O2C-Gerätes die Parameter der Mirkrozirkulation der Haut zu beobachten, sowie die pharmakologische Beeinflussung zu monitorisieren. Ein signifikanter Anstieg der Sauerstoffsättigung des Gewebes sowie des Blutflusses zeigte sich im Gesunden nach Wirkstoffapplikation. Postoperative Ergebnisse nach Lappenplastiken sind bislang nur am Tiermodell erhoben. Die Studie liefert nun eine Grundlage und Referenz an gesunder Haut zur weiteren Untersuchung an ischämischen Replantaten oder nach Lappenplastiken

    Plasma processing of closed nuclear fuel cycle waste

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    В работе предложен плазменный метод переработки отходов замкнутого ядерного топливного цикла в виде водно-солеорганической композиции. Этот метод имеет несколько преимуществ и позволяет безопасно перерабатывать такой материал. Определен оптимальный состав для утилизации данного отхода в плазме. Равновесные составы показали, что в процессе плазменной обработки образуются N[2], CO[2], H[2]O, а также FeCl[3] и Fe[2]O[3 в конденсированной фазе. Отсутствие сажи является показателем того, что процесс переработки является экологически безопасным.The work proposed the plasma method of processing closed nuclear fuel cycle wastes in the form of a water-salt-organic composition. This method has several advantages and allows recycling such material safely. The optimal composition for recycling in plasma was determined. Equilibrium compositions showed that in the process of plasma processing N[2], CO[2], H[2]O and also FeCl[3] и Fe[2]O[3] in the condensed phase were formed. Lack of soot is an indicator that the recycling process is environmentally safe

    Impact of spatial organization on a novel auxotrophic interaction among soil microbes

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    A key prerequisite to achieve a deeper understanding of microbial communities and to engineer synthetic ones is to identify the individual metabolic interactions among key species and how these interactions are affected by different environmental factors. Deciphering the physiological basis of species–species and species–environment interactions in spatially organized environments requires reductionist approaches using ecologically and functionally relevant species. To this end, we focus here on a defined system to study the metabolic interactions in a spatial context among the plant-beneficial endophytic fungus Serendipita indica, and the soil-dwelling model bacterium Bacillus subtilis. Focusing on the growth dynamics of S. indica under defined conditions, we identified an auxotrophy in this organism for thiamine, which is a key co-factor for essential reactions in the central carbon metabolism. We found that S. indica growth is restored in thiamine-free media, when co-cultured with B. subtilis. The success of this auxotrophic interaction, however, was dependent on the spatial and temporal organization of the system; the beneficial impact of B. subtilis was only visible when its inoculation was separated from that of S. indica either in time or space. These findings describe a key auxotrophic interaction in the soil among organisms that are shown to be important for plant ecosystem functioning, and point to the potential importance of spatial and temporal organization for the success of auxotrophic interactions. These points can be particularly important for engineering of minimal functional synthetic communities as plant seed treatments and for vertical farming under defined conditions

    Claudin-1 induced sealing of blood-brain barrier tight junctions ameliorates chronic experimental autoimmune encephalomyelitis

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    In experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis (MS), loss of the blood-brain barrier (BBB) tight junction (TJ) protein claudin-3 correlates with immune cell infiltration into the CNS and BBB leakiness. Here we show that sealing BBB TJs by ectopic tetracycline-regulated expression of the TJ protein claudin-1 in Tie-2 tTA//TRE-claudin-1 double transgenic C57BL/6 mice had no influence on immune cell trafficking across the BBB during EAE and furthermore did not influence the onset and severity of the first clinical disease episode. However, expression of claudin-1 did significantly reduce BBB leakiness for both blood borne tracers and endogenous plasma proteins specifically around vessels expressing claudin-1. In addition, mice expressing claudin-1 exhibited a reduced disease burden during the chronic phase of EAE as compared to control littermates. Our study identifies BBB TJs as the critical structure regulating BBB permeability but not immune cell trafficking into CNS during EAE, and indicates BBB dysfunction is a potential key event contributing to disease burden in the chronic phase of EAE. Our observations suggest that stabilizing BBB barrier function by therapeutic targeting of TJs may be beneficial in treating MS, especially when anti-inflammatory treatments have faile

    Mineralogical characterization of scalings formed in geothermal sites in the Upper Rhine Graben before and after the application of sulfate inhibitors

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    Scale formation processes in the surface installations of geothermal power plants may have a negative effect on power plant performance. In addition, scales formed within the geothermal water circuit frequently accumulate natural radionuclides. Consequently, scale formation may lead to radiation dose rates, which are of radiological concern, and deposits, which may have to be disposed as radioactive waste. In order to minimize these problems and to foster geothermal power plant availability, it is of major interest to understand scale formation processes and to develop methods for their inhibition. One important pre-requisite towards this goal is a sound mineralogical and geochemical characterization of the formed material. Geothermal brines at sites in the Upper Rhine Graben are in general highly mineralized and become, upon cooling in the heat exchanger, supersaturated with respect to sulfate solid-solutions, e.g. (Ba,Sr)SO4, and other mineral phases. Some geothermal power plants very successfully tested the application of sulfate scaling inhibitors. Here we present mineralogical analyses of scale samples from geothermal power plants in the Upper Rhine Valley deposited in absence and presence of sulfate scaling inhibitors. Solid samples are investigated using wet-chemistry (after digestion), XRPD, SEM-EDX, XPS, EA-IRMS, Raman spectroscopy, and XANES (for explanation of abbreviations, see main text). Samples of scales deposited in the absence of a sulfate scaling inhibitor mainly consist of two phases. The largest part is made up of a barite type (Ba,Sr,Ca)SO4 solid-solution. Traces of Ra occurring in the scaling are assumed to be incorporated in the barite type solid solution. Further minor phases are sulfide phases, either an Xray amorphous nano-particulate phase or galena (PbS). Since the application of the sulfate inhibitor, sulfate minerals are no longer detectable in the scale samples. Subsequent scalings are Pb-dominated and consist mainly of galena (PbS), elemental lead (Pb), arsenic (As) and antimony (Sb). As and Sb are likely present as a nanocrystalline intermetallic mixed compound ((Sb, As) or Pb3(Sb,As)2S3). The absence of barite-type minerals demonstrates the success of the application of the sulfate inhibitor. The precipitation of elemental Pb, As, and Sb, which are more noble than iron, may enhance the corrosion of mild steel pipes in the geothermal water circuit. Elution tests and oxidation of the scalings upon storage at atmospheric conditions demonstrate that proper disposal of the toxic heavy metal and metalloid containing scalings may be challenging
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