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1.

Bacillus methylotrophicus M4-96 is a beneficial rhizobacterium that has been isolated from the rhizosphere of maize (Zea mays). In this study, we investigated its efficacy as a plant growth promoter for strawberry in vitro, as well as its ability to induce callose deposition in leaves to reduce the severity of Botrytis cinerea infection. Two methods of plant-bacterial interaction were used: inoculation near the root and emission of volatile compounds with no physical contact. Plant biomass increased under both treatments, but with developmental parameters of the plants differentially stimulated by each method. Root inoculation increased petiole number and root length, whereas bacterial volatiles increased petiole length and root number. A chemical analysis of the bacterial culture revealed the presence of indole acetic acid (0.21 μg L−1) and gibberellic acid (6.16 μg L−1). Acetoin was previously identified as the major volatile produced by the bacteria, and its application to strawberry explants increased their growth and development. Furthermore, when acetoin and both phytoregulators were added to the culture media, these positive effects were enhanced. The inoculation method also affected the size and quantity of callose deposits in the leaves. Treatment with volatiles increased callose deposition in the leaves by up to five-fold, which promoted a rapid defense reaction that inhibited the incidence of gray mold by reinforcing cell wall. Taken together, our results show that B. methylotrophicus M4-96 promotes growth and induces systemic resistance in strawberry plants.

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3.
The amiloride-sensitive epithelial Nachannel (ENaC) is a heteromultimeric channel made of three αβγ subunits. The structures involved in the ion permeation pathway have only been partially identified, and the respective contributions of each subunit in the formation of the conduction pore has not yet been established. Using a site-directed mutagenesis approach, we have identified in a short segment preceding the second membrane-spanning domain (the pre-M2 segment) amino acid residues involved in ion permeation and critical for channel block by amiloride. Cys substitutions of Gly residues in β and γ subunits at position βG525 and γG537 increased the apparent inhibitory constant (K i) for amiloride by >1,000-fold and decreased channel unitary current without affecting ion selectivity. The corresponding mutation S583 to C in the α subunit increased amiloride K i by 20-fold, without changing channel conducting properties. Coexpression of these mutated αβγ subunits resulted in a nonconducting channel expressed at the cell surface. Finally, these Cys substitutions increased channel affinity for block by externalZn2+ ions, in particular the αS583C mutant showing a K i for Zn2+of 29 μM. Mutations of residues αW582L or βG522D also increased amiloride K i, the later mutation generating a Ca2+blocking site located 15% within the membrane electric field. These experiments provide strong evidence that αβγ ENaCs are pore-forming subunits involved in ion permeation through the channel. The pre-M2 segment of αβγ subunits may form a pore loop structure at the extracellular face of the channel, where amiloride binds within the channel lumen. We propose that amiloride interacts with Na+ions at an external Na+binding site preventing ion permeation through the channel pore.  相似文献   

4.
A reproducible and efficient protoplast to plant-system has been developed for strawberry. By using young shoots growing on medium supplemented with cytokinin we were able to exclude the detrimental enzyme Pectolyase from our enzyme solution. The more gentle isolation procedure reported in this paper, together with the agarose-embedding system had a pronounced effect on protoplast viability and growth. Plant regeneration was enhanced by using thidiazuron instead of benzyladenine. Flow cytometric measurement of the DNA content in protoplast derived plants revealed that 27 out of 51 plants contained the amount of DNA corresponding to octoploid level. Fifteen plants exhibited chromosome doubling(16×), one was diplodecaploid(12×) and eight plants mixoploid.  相似文献   

5.
Three strawberry (Fragaria × ananassa Duch.) cultivars Rainier, Totem and Selva were grown under greenhouse conditions in a Parkhill sandy loam soil with a background DTPA-extractable Cd concentration of 0.18 mg kg-1 and a pH of 5.1. Experimental treatments included combinations of 4 Cd applications (0, 15, 30 and 60 mg Cd kg-1 soil) applied as CdSO4 and 2 soil pH values 5.1 and 6.8. Both the application of Cd and pH of the soil significantly affected plant growth, yield and Cd accumulation in plant tissue anf fruit. Although roots accumulated the highest concentrations of Cd of all plant parts investigated, increased soil Cd application reduced leaf weight more than root weight. In general, yield of strawberries was decreased by an increase in amount of soil-applied Cd, however the yield response varied among cultivars. At 60 mg Cd kg-1 soil, yield of Rainier cultivar was reduced to 17.6% of control plants. Over 90% of total Cd taken up by plants grown in Cd-treated soil accumulated in roots, regardless of the Cd level in the soil. Root Cd concentrations ranged from 2.6 mg kg-1 (control plants) to 505.7 mg kg-1 (Totem plants grown in soil at highest Cd and a soil pH 5.1) and were directly related to soil Cd concentrations. Cd translocation from roots to leaves and fruit was very limited, resulting in a maximum Cd concentration in root leaf tissue of 10.2 mg kg-1. Accumulation of Cd in fruit was found to correlate well with leaf Cd, although even at the highest amount of applied Cd, fruit Cd concentration did not exceed 700 g kg-1 of fresh weight.Contribution no. 951  相似文献   

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7.
To study the detachment stress on the ripeness of strawberry fruit, physiological characteristics of strawberry fruit on and off plant during ripeness and senescence processes were investigated. The results indicated that the ripeness of strawberry fruit upon detachment was accelerated, in terms of firmness, soluble solid content and especially color development. The color of fruit off plant changed rapidly from white to full red in 1–2 days. The respiratory rate in fruit off plant was strengthened, higher than that on plant. Abscisic acid level and ethylene production in fruit off plant were also higher than those on plant and auxin degradation was exacerbated by detachment. Expression levels of FaMYB1, FabHLH3 and FaTTG1 were generally reduced with phenotypes of redder color and more anthocyanin accumulation in fruit off plant. Results also suggested that the detachment initially stimulated ethylene and abscisic acid production and auxin degradation, which modulated ripening-related gene expression and at last enhanced fruit pigmentation.  相似文献   

8.
Woo  S.Y.  Kwon  K.W.  Lee  J.C.  Choi  J.H.  Kang  B.S. 《Photosynthetica》2003,41(2):319-320
After SO2 fumigation, Quercus acutissima and Pinus densiflora maintained high net photosynthetic rate (P N) and did not show visible symptoms of damage. In contrast, Populus alba×glandulosa and Acanthopanax sessiliflorus had significantly reduced P N and showed visible necrosis. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

9.

Background/Aim

The Questionnaire: Children with Difficulties (QCD) is a parent-assessed questionnaire designed to evaluate child’s difficulties in functioning during specific periods of the day. This study aimed to evaluate difficulties in daily functioning of children and adolescents with pervasive developmental disorder (PDD) using the QCD. Results were compared with those for a community sample.

Methods

A case–control design was used. The cases comprised elementary school students (182 males, 51 females) and junior high school students (100 males, 39 females) with PDD, whereas a community sample of elementary school students (568 males, 579 females) and junior high school students (180 males, 183 females) was enrolled as controls. Their behavior was assessed using the QCD, the Tokyo Autistic Behavior Scale (TABS), the ADHD-rating scale (ADHD-RS), and the Oppositional Defiant Behavior Inventory (ODBI) for elementary and junior high school students, respectively. Effects of gender and diagnosis on the QCD scores were analyzed. Correlation coefficients between QCD and TABS, ADHD-RS, and ODBI scores were analyzed.

Results

The QCD scores for the children with PDD were significantly lower compared with those from the community sample (P < 0.001). Significantly strong correlations were observed in more areas of the ADHD-RS and ODBI scores compared with the TABS scores.

Conclusions

Children with PDD experienced greater difficulties in completing basic daily activities; moreover, their QCD scores revealed stronger associations with their ADHD-RS and ODBI scores in comparison with their TABS scores. The difficulties of PDD, ADHD and OBDI symptoms combined in children makes it necessary to assess all diagnoses before any therapy for PDD is initiated in order to be able to evaluate its results properly.  相似文献   

10.
In order to prove that thermal ionization is the main mechanism for sustaining a high-current low-pressure diffuse discharge in crossed E × H fields, the ion temperature was estimated by analyzing the Doppler broadening of a spectral line. The emission spectrum from discharge plasma was recorded using a specially designed echelle spectrograph with compensated astigmatism and with a resolution of 0.02 nm.  相似文献   

11.
Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher’s exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P?<?0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.  相似文献   

12.
Uses and Conservation of Plant Species in a National Park—A Case Study of Ben En, Vietnam. This paper surveys the use of wild and cultivated plants by local people in Ben En National Park, Vietnam, and analyzes its impact on the conservation status of some of the utilized species. A total of 208 species used for a range of nonmedicinal purposes are listed. See Hoang et al. (2008a) for 230 medicinal plants used in the park. Most species are used for food. The use of plants contributes very significantly to the livelihood of local people in the park, but the current use patterns are not sustainable and would lead to local extinction of rare and endangered species if no additional conservation measures are introduced. Men collect nonmedicinal plants more often than women. A total of 38 useful plant species are commercialized, and contribute 12% of the average income of individual households. Bamboo shoots of Schizostachyum funghomii (Poaceae) are the most important for income generation. The monetary equivalent of noncommercialized useful plants probably far exceeds the value of the traded plant products. Plant use is independent of the ethnicity of the different populations living in the park. Larger households make use of a greater variety of useful plant species than small families. Abundant species in the forest have a higher use index (UI) than less common species. Out of the 208 useful species, as many as 27 were found to be endangered locally, many more than the 11 or 8 endangered species included in national or global red lists. Currently, useful plants, especially important timber trees, are more abundant in the less disturbed parts of the park, far away from the villages, indicating the pressures of illegal logging and harvesting near villages on the ecosystems.  相似文献   

13.
This study assessed the impact of either cadmium chloride (Cd) or sodium selenite (Se) alone or in combination on male Sprague–Dawley rats. For this purpose, body and liver weights, comet and TUNEL assays, histological analysis and levels of lipid peroxidation and antioxidants in liver were determined in four groups of male Sprague–Dawley rats. The rats were given subcutaneous doses of 1 mg/kg body weight (BW) of either normal saline (control = Ct) or Cd or Se or Cd plus Se (Cd + Se) on alternate days for 4 weeks. The Cd group showed increased DNA damage, apoptosis and hepatic levels of lipid peroxidation and altered histology. Conversely, the antioxidant levels in this group were decreased as compared with the control group. The Se group also showed DNA damage, apoptosis and altered histology and reduced catalase activity, but it was less severe than the Cd group. In the Cd + Se group, ameliorating effects of Se on Cd-induced changes were observed. While the Se was able to curtail the toxic effect of Cd, the Cd or Se alone were genotoxic and cytotoxic for rats receiving a high pharmacological but non-fatal dose of 1 mg/kg BW.  相似文献   

14.
Many rural communities no longer have abundant forest areas for firewood collection. Based on this scenario, we evaluated how the scarcity of forest environments influences the collection and use of this resource in rural areas. A community located in the Atlantic Forest region of northeastern Brazil, which already lacks forest areas for firewood, was selected for field research. We observed that despite this context of forest scarcity, firewood remains the main source of fuel energy in the community. In total, 27 species of wood were cited, with an emphasis on exotic species in terms of number of citations. The perceived wood quality explained the frequency of plant use, but not the number of consumers. This can be explained by the difficulty of access to some species considered of better quality, because in the studied region, the plants are usually collected in private areas. Efforts in conservation strategies are recommended to encourage an increase in the frequency of use of the available exotic species in order to safeguard the native ones.  相似文献   

15.
Attempts were made to synthesize seven analogs of µ-conotoxin GIIIA, a specific blocker of muscle sodium channels, by replacing the three Hyp residues (Hyp6, Hyp7, and Hyp17) with various amino acids. Replacement with Ala residue at these positions resulted in a very low isolation yield, suggesting that these three Hyp residues are essential for the folding of the molecule. CD spectra of the synthesized analogs suggest that, once synthesized, the replacement did not affect the three dimensional structure. The inhibitory effects on the twitch contractions of the rat diaphragm showed that the hydroxyl group at side chains of Hyp residues are not essential for the activity.  相似文献   

16.
We conducted a qualitative study in the Emergency Departments (EDs) of four hospitals in order to investigate the perceived scope and causes of ‘diagnostic overshadowing’ – the misattribution of physical symptoms to mental illness – and other challenges involved in the diagnostic process of people with mental illness who present in EDs with physical symptoms. Eighteen doctors and twenty-one nurses working in EDs and psychiatric liaisons teams in four general hospitals in the UK were interviewed. Interviewees were asked about cases in which mental illness interfered with diagnosis of physical problems and about other aspects of the diagnostic process. Interviews were transcribed and analysed thematically. Interviewees reported various scenarios in which mental illness or factors related to it led to misdiagnosis or delayed treatment with various degrees of seriousness. Direct factors which may lead to misattribution in this regard are complex presentations or aspects related to poor communication or challenging behaviour of the patient. Background factors are the crowded nature of the ED environment, time pressures and targets and stigmatising attitudes held by a minority of staff. The existence of psychiatric liaison team covering the ED twenty-four hours a day, seven days a week, can help reduce the risk of misdiagnosis of people with mental illness who present with physical symptoms. However, procedures used by emergency and psychiatric liaison staff require fuller operationalization to reduce disagreement over where responsibilities lie.  相似文献   

17.
18.
African American (AA) women are more likely than European American (EA) women to be diagnosed with early, aggressive breast cancer. Possible differences in innate immune pathways (e.g., inflammatory responses) have received little attention as potential mechanisms underlying this disparity. We evaluated distributions of selected genetic variants in innate immune pathways in AA and EA women, and examined their associations with breast cancer risk within the Women’s Circle of Health Study (WCHS). In stage I of the study (864 AA and 650 EA women) we found that genotype frequencies for 35 of 42 tested SNPs (18 candidate genes) differed between AAs and EAs (corroborated by ancestry informative markers). Among premenopausal AA women, comparing variant allele carriers to non-carriers, reduced breast cancer risk was associated with CXCL5-rs425535 (OR=0.61, P=0.02), while among EA women, there were associations with TNFA-rs1799724 (OR =2.31, P =0.002) and CRP-rs1205 (OR=0.54, P=0.01). For postmenopausal women, IL1B-rs1143627 (OR=1.80, P=0.02) and IL1B-rs16944 (OR=1.85, P =0.02) were associated with risk among EA women, with significant associations for TNFA-rs1799724 limited to estrogen receptor (ER) positive cancers (OR=2.0, P =0.001). However, none of the SNPs retained significance after Bonferroni adjustment for multiple testing at the level of P0.0012 (0.05/42) except for TNFA-rs1799724 in ER positive cancers. In a stage II validation (1,365 AA and 1,307 EA women), we extended evaluations for four SNPs (CCL2-rs4586, CRP-rs1205, CXCL5-rs425535, and IL1RN-rs4251961), which yielded similar results. In summary, distributions of variants in genes involved in innate immune pathways were found to differ between AA and EA populations, and showed differential associations with breast cancer according to menopausal or ER status. These results suggest that immune adaptations suited to ancestral environments may differentially influence breast cancer risk among EA and AA women.  相似文献   

19.
Smoking is a risk factor for insulin resistance and metabolic syndrome. However, mechanisms responsible for smoking-induced insulin resistance are unclear. We examined the combined effect of nicotine, a toxic substance in tobacco smoke, and palmitate in the serum physiological concentration range on tumor necrosis factor-α (TNF-α) expression and impairment of glucose uptake in C2C12 myotubes, since smokers do not have increased serum free fatty acid (FFA) concentrations with insulin resistance compared to nonsmokers. C2C12 myotubes were incubated for 24 h with nicotine (1 μmol/l) in the presence or absence of palmitate (200 μmol/l). RT-PCR and Western blotting showed increased TNF-α expression in C2C12 myotubes treated with nicotine in the presence of palmitate. Furthermore, stimulation with nicotine in the presence of palmitate enhanced the production of reactive oxygen species (ROS) and activated the protein kinase C-nuclear factor-κB (PKC-NF-κB) pathway, as detected by dihydroethidium staining and Western blotting, respectively. Consequently, the translocation of GLUT4 to the plasma membrane as well as insulin-stimulated Akt phosphorylation was impaired, and glucose uptake to the myocytes was blocked. In addition, the production of ROS was suppressed by 4-hydroxy-TEMPO, and inhibition of GLUT4 translocation to the plasma membrane was canceled. These results suggest that in C2C12 myotubes, nicotine in the presence of palmitate enhanced the production of ROS and the expression of TNF-α through the PKC-NF-κB pathway; suppressed GLUT4 translocation to the plasma membrane; and impaired glucose uptake to cells. This pathway represents a possible mechanism by which smoking induces insulin resistance in the body.  相似文献   

20.
Five brain-derived and 17 urinary oligomannose-type oligosaccharides were isolated by ion-exchange chromatography on Mono Q or Dowex, followed by HPLC on Lichrosorb-NH2 from a Persian cat suffering from -mannosidosis. The structures ofthe carbohydrate chains were determined by 500- or 600-MHz1H-NMR spectroscopy. Different oligosaccharide patterns were found in brain and urine. 99% of the urinary oligosaccharides possess an (1-6)-linked mannose residue attached to -mannose, whereas only 5% of the brain-derived oligosaccharides contain such a residue. Furthermore, of the urinary carbohydrate chains 71% end with Man1-4GlcNAc1-4GlcNAc and 29% end with Man1-4GlcNAc, whereas the corresponding amounts are 23% and 77%, respectively, for the brain-derived oligosaccharides.Abbreviations MLEV-17 composite pulse devised by M. Levitt - HOHAHA homonuclear Hartman-Hahn spectroscopy - TPPI time-proportional phase incrementation - 2D two dimensional - GlcNAc N-acetylglucosamine - Man mannose - Fuc fucose  相似文献   

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