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111.
Peter Salzer Gerhard Hebe Andreas Reith Barbara Zitterell-Haid Harald Stransky Katja Gaschler Achim Hager 《Planta》1996,198(1):118-126
Elicitors released from hyphae or cell walls of the ectomycorrhizal fungus Hebeloma crustuliniforme (Bull. ex Fries.) Quél. induced in suspension-cultured cells of Picea abies (L.) Karst. a set of fast reactions: (i) an immediate efflux of Cl– into the medium, followed by a K+ efflux; (ii) an influx of Ca2+ (measured as accumulation of 45Ca2+ in the cells); (iii) a phosphorylation of a 63-kDa protein and dephosphorylation of a 65-kDa protein (detectable by 4 min after elicitor application); (iv) an alkalinization of the medium, and (v) a transient synthesis of H2O2. The removal of extracellular Ca2+ by EGTA delayed the elicitor-induced alkalinization. A further reduction of this response could be achieved by TMB-8 an inhibitor of Ca2+ release from intracellular stores. Moreover, the inhibition of protein kinase activity by staurosporine prevented the extracellular alkalinization completely. However, the effectiveness of the elicitors in inducing the extracellular alkalinization was strongly impaired by constitutively secreted enzymes of spruce cells which cleaved the elicitors to inactive fragments. It is suggested that in ectomycorrhizae the efficacy of elicitors released from fungal cell walls is controlled by apoplastic enzymes of the host; the plant itself is able to reduce the activity of fungal elicitors on their way through the plant cell wall. But those elicitors which finally reach the plasma membrane of host cells induce reactions that are similar to the early defense reactions in plant-pathogen interactions.Abbreviations DW
dry weight
- FW
fresh weight
- TMB-8
3,4,5 trimethoxybenzoic acid 8-(diethylamino)-octyl ester
We thank Prof. M. Zenk (Universität München, Germany) for providing spruce cell cultures, and Dr. I. Kottke (Universität Tübingen, Germany) for isolates of Hebeloma crustuliniforme Tü 704. We are also thankful to Dr. W. Mayer (Universität Tübingen) for valuble discussions. This work was supported by Deutsche Forschungsgemeinschaft. B. Zitterell-Haid was financed by Graduiertenkolleg Interaktion in Waldökosystemen (supported by Deutsche Forschungsgemeinschaft) and G. Hebe by a scholarship of the Landesgraduiertenförderungsgesetz. 相似文献
112.
113.
Schirmer RH Coulibaly B Stich A Scheiwein M Merkle H Eubel J Becker K Becher H Müller O Zich T Schiek W Kouyaté B 《Redox report : communications in free radical research》2003,8(5):272-275
Methylene blue has intrinsic antimalarial activity and it can act as a chloroquine sensitizer. In addition, methylene blue must be considered for preventing methemoglobinemia, a serious complication of malarial anemia. As an antiparasitic agent, methylene blue is pleiotropic: it interferes with hemoglobin and heme metabolism in digestive organelles, and it is a selective inhibitor of Plasmodium falciparum glutathione reductase. The latter effect results in glutathione depletion which sensitizes the parasite for chloroquine action. At the Centre de Recherche en Santé de Nouna in Burkina Faso, we study the combination of chloroquine with methylene blue (BlueCQ) as a possible medication for malaria in endemic regions. A pilot study with glucose-6-phosphate dehydrogenase-sufficient adult patients has been conducted recently. 相似文献
114.
Katja Petzold Diane Poster Fabienne Krauer Katharina Spanaus Gustav Andreisek Thi Dan Linh Nguyen-Kim Ivana Pavik Thien Anh Ho Andreas L. Serra Laura Rotar 《PloS one》2015,10(4)
Background
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by a decline in renal function at late disease stage when the majority of functional renal parenchyma is replaced by cystic tissue. Thus, kidney function, assessed by estimated glomerular filtration rate (eGFR) does not well represent disease burden in early disease. Here, we investigated various urinary markers for tubular injury and their association with disease burden in ADPKD patients at early disease course.Methods
ADPKD patients between 18 and 40 years with an eGFR greater or equal to 70 ml per min per 1.73m2 were eligible for this cross-sectional study. Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL), Kidney Injury Molecule-1 (KIM-1), and Uromodulin (UMOD) were investigated by Enzyme-Linked Immunosorbent Assay. Clara Cell Protein 16 (CC16) was investigated by Latex Immuno Assay. Cryoscopy was performed to assess urine osmolality and Urinary Albumin-to-Creatinine Ratio (UACR) was calculated. The association and the predictive properties of the markers on eGFR and height adjusted total kidney volume (htTKV) was evaluated using multiple regression analysis, incorporating different control variables for adjustment. Internal bootstrapping validated the obtained results.Results
In 139 ADPKD patients (age 31 ±7 years, mean eGFR of 93 ± 19 ml per min per 1.73 m2) the total kidney volume was negatively correlated with eGFR and UMOD and positive associated with age, UACR, KIM-1 and urine osmolality after adjustment for possible confounders. Urine osmolality and htTKV were also associated with eGFR, whereas no association of CC16, NGAL and UMOD with eGFR or htTKV was found.Conclusion
UACR and urinary KIM-1 are independently associated with kidney size but not with renal function in our study population. Urine osmolality was associated with eGFR and kidney volume following adjustment for multiple confounders. Despite statistical significance, the clinical value of our results is not yet conceivable. Further studies are needed to evaluate the property of the aforementioned biomarkers to assess disease state at early ADPKD stage. 相似文献115.
116.
Tobias Schwarzmüller Biao Ma Ekkehard Hiller Fabian Istel Michael Tscherner Sascha Brunke Lauren Ames Arnaud Firon Brian Green Vitor Cabral Marina Marcet-Houben Ilse D. Jacobsen Jessica Quintin Katja Seider Ingrid Frohner Walter Glaser Helmut Jungwirth Sophie Bachellier-Bassi Murielle Chauvel Ute Zeidler Dominique Ferrandon Toni Gabaldón Bernhard Hube Christophe d'Enfert Steffen Rupp Brendan Cormack Ken Haynes Karl Kuchler 《PLoS pathogens》2014,10(6)
The opportunistic fungal pathogen Candida glabrata is a frequent cause of candidiasis, causing infections ranging from superficial to life-threatening disseminated disease. The inherent tolerance of C. glabrata to azole drugs makes this pathogen a serious clinical threat. To identify novel genes implicated in antifungal drug tolerance, we have constructed a large-scale C. glabrata deletion library consisting of 619 unique, individually bar-coded mutant strains, each lacking one specific gene, all together representing almost 12% of the genome. Functional analysis of this library in a series of phenotypic and fitness assays identified numerous genes required for growth of C. glabrata under normal or specific stress conditions, as well as a number of novel genes involved in tolerance to clinically important antifungal drugs such as azoles and echinocandins. We identified 38 deletion strains displaying strongly increased susceptibility to caspofungin, 28 of which encoding proteins that have not previously been linked to echinocandin tolerance. Our results demonstrate the potential of the C. glabrata mutant collection as a valuable resource in functional genomics studies of this important fungal pathogen of humans, and to facilitate the identification of putative novel antifungal drug target and virulence genes. 相似文献
117.
Polona Žigon Katjuša Mrak-Poljšak Katja Lakota Matic Terčelj Saša Čučnik Matija Tomsic Snezna Sodin-Semrl 《Metabolomics : Official journal of the Metabolomic Society》2016,12(5):92
Introduction
Human primary cells originating from different locations within the body could differ greatly in their metabolic phenotypes, influencing both how they act during physiological/pathological processes and how susceptible/resistant they are to a variety of disease risk factors. A novel way to monitor cellular metabolism is through cell energetics assays, so we explored this approach with human primary cell types, as models of sclerotic disorders.Objectives
In order to better understand pathophysiological processes at the cellular level, our goals were to measure metabolic pathway activities of endothelial cells and fibroblasts, and determine their metabolic phenotype profiles.Methods
Biolog Phenotype MicroArray? technology was used for the first time to characterize metabolic phenotypes of diverse primary cells. These colorimetric assays enable detection of utilization of 367 specific biochemical substrates by human endothelial cells from the coronary artery (HCAEC), umbilical vein (HUVEC) and normal, healthy lung fibroblasts (NHLF).Results
Adenosine, inosine, d-mannose and dextrin were strongly utilized by all three cell types, comparable to glucose. Substrates metabolized solely by HCAEC were mannan, pectin, gelatin and prevalently tricarballylic acid. HUVEC did not show any uniquely metabolized substrates whereas NHLF exhibited strong utilization of sugars and carboxylic acids along with amino acids and peptides.Conclusion
Taken together, we show for the first time that this simple energetics assay platform enables metabolic characterization of primary cells and that each of the three human cell types examined gives a unique and distinguishable profile.118.
Katja Behnke Maaria Loivamäki Ina Zimmer Heinz Rennenberg Jörg-Peter Schnitzler Sandrine Louis 《Photosynthesis research》2010,104(1):5-17
In the present study, we combined transient temperature and light stress (sunfleck) and comparably analyzed photosynthetic
gas exchange in Grey poplar which has been genetically modified in isoprene emission capacity. Overall, we demonstrate that
for poplar leaves the ability to emit isoprene is crucial to maintain photosynthesis when exposed to sunflecks. Net CO2 assimilation and electron transport rates were strongly impaired in sunfleck-treated non-isoprene emitting poplars. Similar
impairment was not detected when the leaves were exposed to high light (lightflecks) only. Within 10 h non-isoprene emitting
poplars recovered from sunfleck-related impairment as indicated by chlorophyll fluorescence and microarray analysis. Unstressed
leaves of non-isoprene emitting poplars had higher ascorbate contents, but also higher contents of malondialdehyde than wild-type.
Microarray analyses revealed lipid and chlorophyll degradation processes in the non-isoprene emitting poplars. Thus, there
is evidence for an adjustment of the antioxidative system in the non-isoprene emitting poplars even under normal growth conditions. 相似文献
119.
Different environmental stresses to a plant may result in similar responses at the cellular and molecular level. This is due
to the fact that the impacts of the stressors trigger similar strains and downstream signal transduction chains. A good example
for an unspecific response is the reaction to stressors which induce water deficiency e.g. drought, salinity and cold, especially
frost. The stabilizing effect of liquid water on the membrane bilayer can be supported by compatible solutes and special proteins.
At the metabolic level, osmotic adjustment by synthesis of low-molecular osmolytes (carbohydrates, betains, proline) can counteract
cellular dehydration and turgor loss. Taking the example of Pinus sylvestris, changes at the level of membrane composition, and concomitantly of photosynthetic capacity during frost hardening is shown.
Additionally the effect of photoperiod as measured via the phytochrome system and the effect of subfreezing temperatures on
the incidence of frost hardening is discussed. Extremely hydrophilic proteins such as dehydrins are common products protecting
not only the biomembranes in ripening seeds (late embryogenesis abundant proteins) but accumulate also in the shoots and roots
during cold adaptation, especially in drought tolerant plants. Dehydrins are characterized by conserved amino acid motifs,
called the K-, Y-or S-segments. Accumulation of dehydrins can be induced not only by drought, but also by cold, salinity,
treatment with abscisic acid and methyl jasmonate. Positive effects of the overexpression of a wild chickpea (Cicer pinnatifidum) dehydrin in tobacco plants on the dehydration tolerance is shown. The presentation discusses the perception of cold and
drought, the subsequent signal transduction and expression of genes and their products. Differences and similarities between
the plant responses to both stressors are also discussed. 相似文献
120.
The three-dimensional pattern of phloem and xylem in 10-d-to two-month-old tumors induced by Agrobacterium tumefaciens (C58) and in adjacent Ricinus communis L. stem tissues was studied in thick sections by clearing with lactic acid and by staining with lacmoid. The crown galls contained two types of vascular strands: treelike branched bundles, which developed towards the tumor surface in fast-growing regions, and globular bundles in the slowly developing parts. Both types of vascular bundles contained xylem and phloem and were continuous with the vascular system of the host plant. The tumor bundles were interconnected by a dense net of phloem anastomoses, consisting of sieve tubes but no vessels. These vascular patterns reflect the apparent synthesis sites, concentration gradients and flow pathways of the plant hormones additionally produced in the tumors upon expression of the T-DNA-encoded genes. The A. tumefaciens-induced crown gall affected vascular differentiation in the host stem. In the basipetal direction, the tumor induced more xylem differentiation directly below it, where the crown-gall bundles joined the vascular system of the host. In the centripetal direction, the crown gall caused the development of pathologic xylem characterized by narrow vessels, giant rays and absence of fibers. On the other hand, most probably as a consequence of its gibberellic acid content, the host plant stimulated a local differentiation of regenerative phloem and xylem fibers with unique ramifications, only at the base of the tumor. However, fibers were absent from the main body of the crown gall. The study shows that A. tumefaciens-induced crown galls are characterized by a sophisticated network of vascular tissues in the tumor and are accompanied by a perturbated vessel system in the host. The hormonal mechanisms controlling vascular differentiation in the tumor and neighboring host tissues are discussed. In addition, the gall constriction hypothesis is proposed for explaining the mechanism which gives priority in water supply to the growing gall over the host shoot.We thank Dr. Zs. Koncz (Max-Planck-Institut für Züchtungsforschung, Köln, Germany) for Agrobacterium strains and the Deutsche Forschungsgemeinschaft (SFB 199) for financial support to C.I.U. 相似文献