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According to their lifestyle, plant pathogens are divided into biotrophic and necrotrophic organisms. Biotrophic pathogens exclusively nourish living host cells, whereas necrotrophic pathogens rapidly kill host cells and nourish cell walls and cell contents. To this end, the necrotrophic fungus Botrytis cinerea secretes large amounts of phytotoxic proteins and cell wall-degrading enzymes. However, the precise role of these proteins during infection is unknown. Here, we report on the identification and characterization of the previously unknown toxic protein hypersensitive response-inducing protein 1 (Hip1), which induces plant cell death. We found the adoption of a structurally conserved folded Alternaria alternata Alt a 1 protein structure to be a prerequisite for Hip1 to exert its necrosis-inducing activity in a host-specific manner. Localization and the induction of typical plant defense responses by Hip1 indicate recognition as a pathogen-associated molecular pattern at the plant plasma membrane. In contrast to other secreted toxic Botrytis proteins, the activity of Hip1 does not depend on the presence of the receptor-associated kinases BRI1-associated kinase 1 and suppressor of BIR1-1. Our results demonstrate that recognition of Hip1, even in the absence of obvious enzymatic or pore-forming activity, induces strong plant defense reactions eventually leading to plant cell death. Botrytis hip1 overexpression strains generated by CRISPR/Cas9 displayed enhanced infection, indicating the virulence-promoting potential of Hip1. Taken together, Hip1 induces a noncanonical defense response which might be a common feature of structurally conserved fungal proteins from the Alt a 1 family.

The secreted Botrytis protein hypersensitive response inducing protein 1 activates plant defense to kill plant cells.  相似文献   
93.
Accumulating evidence suggests a higher risk for cardiovascular diseases among individuals with mental disorders, but very little is known about the risk for overall and specific groups of cardiovascular diseases in people with attention‐deficit/hyperactivity disorder (ADHD). To fill this knowledge gap, we investigated the prospective associations between ADHD and a wide range of cardiovascular diseases in adults. In a nationwide population‐based cohort study, we identified 5,389,519 adults born between 1941 and 1983, without pre‐existing cardiovascular diseases, from Swedish registers. The study period was from January 1, 2001 to December 31, 2013. Incident cardiovascular disease events were identified according to ICD codes. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated using Cox proportional hazards regression model, with ADHD as a time‐varying exposure. After an average 11.80 years of follow‐up, 38.05% of individuals with ADHD versus 23.57% of those without ADHD had at least one diagnosis of cardiovascular disease (p<0.0001). ADHD was significantly associated with increased risk of any cardiovascular disease (HR=2.05, 95% CI: 1.98‐2.13) after adjusting for sex and year of birth. Further adjustments for education level, birth country, type 2 diabetes mellitus, obesity, dyslipidemia, sleep problems and heavy smoking attenuated the association, which however remained significant (HR=1.84, 95% CI: 1.77‐1.91). Further adjustment for psychiatric comorbidities attenuated but could not fully explain the association (HR=1.65, 95% CI: 1.59‐1.71). The strongest associations were found for cardiac arrest (HR=2.28, 95% CI: 1.81‐2.87), hemorrhagic stroke (HR=2.16, 95% CI: 1.68‐2.77), and peripheral vascular disease/arteriosclerosis (HR=2.05, 95% CI: 1.76‐2.38). Stronger associations were observed in males and younger adults, while comparable associations were found among individuals with or without psychotropic medications and family history of cardiovascular diseases. These data suggest that ADHD is an independent risk factor for a wide range of cardiovascular diseases. They highlight the importance of carefully monitoring cardiovascular health and developing age‐appropriate and individualized strategies to reduce the cardiovascular risk in individuals with ADHD.  相似文献   
94.
In East Germany, a high percentage of species-rich, semi-natural dry grasslands has been converted into species-poor communities dominated either by Poa angustifolia or Festuca rupicola. The disappearance of low-intensity types of agricultural land-use such as mowing and grazing has been the cause for the decline of many grassland species, as lack of biomass extraction leads to a new situation in competition. Here we evaluate the performance of the rare forb Campanula glomerata in competition with P. angustifolia and F. rupicola using a replacement design experiment. C. glomerata responded to the presence of these grass species in contrasting ways: whereas the presence of P. angustifolia had a negative effect on C. glomerata biomass and fitness, the presence of F. rupicola affected the forb in a positive way. The results of an additional sowing experiment revealed that the germination and establishment rates of C. glomerata decrease in accordance with increasing density of P. angustifolia. Thus the response of this rare forb varies among neighbour species.  相似文献   
95.
We have determined the crystal structure of apo-CusF, a periplasmic protein involved in copper and silver resistance in Escherichia coli. The protein forms a five-stranded beta-barrel, classified as an OB-fold, which is a unique topology for a copper-binding protein. NMR chemical shift mapping experiments suggest that Cu(I) is bound by conserved residues H36, M47, and M49 located in beta-strands 2 and 3. These residues are clustered at one end of the beta-barrel, and their side chains are oriented toward the interior of the barrel. Cu(I) can be modeled into the apo-CusF structure with only minimal structural changes using H36, M47, and M49 as ligands. The unique structure and metal binding site of CusF are distinct from those of previously characterized copper-binding proteins.  相似文献   
96.
We developed a LC-MS/MS method for the quantitative determination of the mercapturic acid (MA) metabolites of acrylamide (AA) AAMA and of its oxidative metabolite glycidamide (GA) GAMA in urine samples from the general population. The method requires 4 mL of urine which is solid phase extracted prior to LC-MS/MS analysis. The metabolites are detected by ESI-tandem mass spectrometry in negative ionisation mode and quantified by isotope dilution. Detection limits ranged down to 1.5 microg/L urine for both AAMA and GAMA. The imprecision expressed as R.S.D. lay between 2% and 6% for both analytes (intra- and inter-assay). First results on a small group of 29 persons out of the general population ranged from 5 to 338 microg/L AAMA and 相似文献   
97.
Experimental and structural investigations of anemochorous dispersal   总被引:3,自引:1,他引:2  
Hensen  Isabell  Müller  Caroline 《Plant Ecology》1997,133(2):169-180
The present paper describes the anemochorous dispersal of representative diaspores of Asteraceae, Dipsacaceae, and Poaceae from xerothermic grassland communities of Central and Northeastern Germany. For eleven species, potential dispersal distance was determined by fall velocity experiments as well as by taking into account the diaspore flight angle under the influence of an artificially-produced, regularly, and horizontally blowing air stream. The latter is a new and comparatively simple method enabling the implementation of mathematical formulas which describe the potential flight capacity of a diaspore for different wind speeds and exposition heights. Surface structures, shown by a scanning electron microscope, were consulted for the interpretation of results.Of the species considered, the best fliers are the diaspores of Asteraceae and Melica ciliata (Poaceae) characterized by a plumous pappus or a hairy lemma. The wing-like attachments of the diaspores of the other investigated Poaceae and Dipsacaceae are clearly less efficient for wind dispersal.The fall rates of the investigated species agree to a great extent with literature data. But a critical comparison of both methods employed shows that fall velocity as a measure of horizontal diaspore flight capacity is only suitable for low wind force < 2 m s-1. With increasing wind force, the dispersal distance of a flying diaspore does not rise in a linear, but rather in an approximately quadratic manner. Thus, in nature, conditions of higher wind forces may be very important for the reachable dispersal distances of well-flying diaspores. This could be of particular significance for nature conservation concepts concerning the vulnerability of species towards isolation within fragmented landscapes.  相似文献   
98.
Ligands of the tumor necrosis factor superfamily (TNFSF) interact with members of the TNF receptor superfamily (TNFRSF). TNFSF ligand-TNFRSF receptor interactions have been intensively evaluated by many groups. The affinities of TNFSF ligand-TNFRSF receptor interactions are highly dependent on the oligomerization state of the receptor, and cellular factors (e.g. actin cytoskeleton and lipid rafts) influence the assembly of ligand-receptor complexes, too. Binding studies on TNFSF ligand-TNFRSF receptor interactions were typically performed using cell-free assays with recombinant fusion proteins that contain varying numbers of TNFRSF ectodomains. It is therefore not surprising that affinities determined for an individual TNFSF ligand-TNFRSF interaction differ sometimes by several orders of magnitude and often do not reflect the ligand activity observed in cellular assays. To overcome the intrinsic limitations of cell-free binding studies and usage of recombinant receptor domains, we performed comprehensive binding studies with Gaussia princeps luciferase TNFSF ligand fusion proteins for cell-bound TNFRSF members on intact cells at 37 °C. The affinities of the TNFSF ligand G. princeps luciferase-fusion proteins ranged between 0.01 and 19 nm and offer the currently most comprehensive and best suited panel of affinities for in silico studies of ligand-receptor systems of the TNF family.  相似文献   
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