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991.
Kato N Sato T Kato C Yajima M Sugiyama J Kanda T Mizuno M Nozaki K Yamanaka S Amano Y 《Extremophiles : life under extreme conditions》2007,11(5):693-698
The effect of pressure on viability and the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus ATCC53582 were investigated. G. xylinus was statically cultivated in a pressurized vessel under 0.1, 30, 60, and 100 MPa at 25°C for 6 days. G. xylinus cells remained viable and retained cellulose producing ability under all the conditions tested, though the production of
cellulose decreased with increasing the pressure. The BCs produced at each pressure condition were analyzed by field emission
scanning electron microscopy (FE-SEM) and Fourier Transform Infrared (FT-IR). FE-SEM revealed that the widths of BC fibers
produced under high pressure decreased as compared with those produced under the atmospheric pressure. By FT-IR, all the BCs
were found to be of Cellulose type I, as the same as typical native cellulose. Our findings evidently showed that G. xylinus possessed a piezotolerant (barotolerant) feature adapting to 100 MPa without losing its BC producing ability. This was the
first attempt in synthesizing BC with G. xylinus under elevated pressure of 100 MPa, which corresponded to the deep sea at 10,000 m. 相似文献
992.
When plants are infested by herbivores, they emit herbivore-induced plant volatiles (HIPVs) that attract carnivorous natural enemies of herbivores. Furthermore, there are increasing evidences that defenses of intact plants against herbivores are primed when exposed to HIPVs. We previously reported that lima bean leaf volatiles induced by the herbivorous mites Tetranychus urticae primed two T. urtiae-induced indirect defenses in neighboring conspecific plants: HIPV emission and extrafloral nectar (EFN) secretion. An intriguing unanswered question is whether the durations of these two defenses are the same. Here, we show that the durations of the two defenses were the same for up to two days after the initiation of T. urticae damage. The two induced primed defense would act as a battery of defense in exposed plants.Key Words: herbivore-induced plant volatiles, indirect, defense, induced response, plant-plant interaction, primingWhen infested by herbivores, plants defend themselves indirectly by emitting herbivore-induced plant volatiles (HIPVs). One of the ecological functions of HIPVs is to attract carnivorous natural enemies of the herbivores.1,2 Recently, it was reported that the emission of HIPVs primed defenses against herbivores in neighboring intact plants.3–7 Thus, HIPVs also mediate interactions between infested and intact plants.8 The enhanced defense in response to HIPVs in intact plants is called ‘priming’, which has been studied intensively in plant-pathogen interactions,9 but not so in plant-insect interactions.We previously reported that exposure to HIPVs emitted from lima bean leaves infested by Tetranychus urticae primed HIPV production in detached intact conspecific leaves.3 We also reported that exposure to HIPVs, produced in response to T. urticae damage,4 primed the induced production of extrafloral nectar (EFN; an alternative food source for predators10,11 in lima bean plants. An intriguing question is whether the two primed defenses work as a battery against T. urticae. To answer this, we examined the duration of primed HIPV production by lima bean plants using the same experimental set-up as our previous study of EFN priming by conspecific plants.4For exposure of plants to HIPVs, we used a 60 × 60 × 60 cm cage with two 30 × 30 cm windows on opposite sides of the cage.12 As odor sources, we used eight plants that had been infested with 60 adult T. urticae females per plant for 1 day. Eight uninfested plants were used as control odor sources. Two uninfested plants were placed in a cage with the odor source plants and exposed to either HIPVs or uninfested plant volatiles (UPVs) for 10 days in a climate-controlled room (25 ± 2°C, 60–70% RH, 16:8; L:D).A Y-tube olfactometer13 was used to examine the response of the predators to HIPVs. Adult female P. persimilis were randomly selected from a colony and individually positioned at the beginning of the iron wire. When test mites reached the end of one arm of the olfactometer, their choice was recorded. We tested the olfactory responses of the predator toward (1) plants infested by T. urticae for two days after exposure to UPVs vs. plants infested by T. urticae for two days after exposure to HIPVs, and (2) plants infested by T. urticae for four days after exposure to UPVs vs. plants infested by T. urticae for four days after exposure to HIPVs.HIPV-exposed plants attracted more predators than UPV-exposed plants in a Y-tube olfactometer when infested by T. urticae for two days (Fig. 1A). By contrast, the predators did not distinguish between HIPV- and UPV-exposed plants when infested by T. urticae for four days (Fig. 1B). Our previous study showed that HIPV-exposed plants secreted significantly larger amounts of EFN secretion than UPV-exposed plants infested by T. urticae for two days under the same experimental condition as in this study.4 However, the difference was not significant when they were infested for four days.4Open in a separate windowFigure 1The olfactory response of P. persimilis females to volatiles from the odor-exposed plants, as determined in a Y-tube olfactometer: (A) plants infested by T. urticae for two days after exposure to UPVs (UPV-exposed—T. urticae 2d) vs. plants infested by T. urticae for two days after exposure to HIPVs (HIPV-exposed—T. urticae 2d), and (B) plants infested by T. urticae for four days after exposure to UPVs (UPV-exposed—T. urticae 4d) vs. plants infested by T. urticae for four days after the exposure to HIPVs (HIPV-exposed—T. urticae 4d). Asterisks beside each bar indicate a significant difference between the first trifoliate leaves and the primary leaves. Asterisks beside a bar indicate a significant difference (binomial test: p < 0.001).Lima bean plants increase the amount of endogenous jasmonic acid after exposure to HIPVs.14 Jasmonic acid, an important plant hormone regulating a defense signaling pathway against herbivores and pathogens,15,16 is reported to be involved in the induction of both volatile emission17,18 and EFN secretion19 in response to T. urticae damage in lima bean plants. The increase of endogenous jasmonic acid in HIPV-exposed plants may partly explain the simultaneous priming of the two defenses.In this study, we showed that the durations of priming of two indirect defenses were roughly the same for up to two days. Priming of these two indirect defenses would thus be a battery of defense at the outset of T. urticae damage. Further study is necessarily to test whether the primed battery of induced defense increases the fitness of the exposed plants. 相似文献
993.
Biomineralization on porous polyester membranes was examined using an improved alternate soaking process (ASP). The effect of ion migration for the formation of hydroxyapatite (HAp) was shown to be crucial. Ion migration was improved by reducing the surface tension by mixing ethanol into an aqueous solution. The resulting hybrid materials were evaluated in terms of calcium content; structure using scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (IR); and protein adsorption. The amount of formed HAp was controlled by the number of ASP cycles and also through the ethanol content of the mixed solvent. As the formation of HAp increased, the formed structure could be verified using SEM, IR, and XRD. Protein adsorption was investigated using albumin, gamma-globulin, and fibrinogen, and the amount of adsorbed protein was well-correlated with that of the formed HAp. This result shows that the total amount of the adsorbed proteins can be regulated by the HAp content. In summary, a tunable protein reservoir was formed on a porous polyester membrane. 相似文献
994.
Komaba J Masuda Y Hashimoto Y Nago S Takamoto M Shibakawa K Nakade S Miyata Y 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,852(1-2):590-597
A highly sensitive and selective method has been developed and validated to determine limaprost, a prostaglandin (PG) E(1) analogue, in human plasma by on-line two-dimensional reversed-phase liquid chromatography-tandem mass spectrometry (2D-LC/MS/MS) due to the lack of efficient methods to determine very low levels of limaprost in plasma. Limaprost and its deuterium derivatives, used as internal standard, were extracted by protein precipitation and following three-step solid phase extractions. After extraction procedure, samples were analyzed by on-line 2D-LC/MS/MS with electrospray ionization in negative mode. The 2D-LC system consists of Phenyl column at first dimension and ODS at second dimension with a trapping column placed between the separation columns. The linear dynamic range of this method was 0.1-10 pg/ml with 3 ml of plasma (r >0.9987). Acceptable precision and accuracy were obtained over the calibration curve ranges. The assay has been successfully used in analyses of human plasma samples to support clinical pharmacokinetics studies. 相似文献
995.
Segawa S Takata Y Wakita Y Kaneko T Kaneda H Watari J Enomoto T Enomoto T 《Bioscience, biotechnology, and biochemistry》2007,71(8):1955-1962
The clinical effects of an oral administration of a hop water extract (HWE) on the improvement of Japanese cedar pollinosis (JCPsis) symptoms were investigated. In a double-blind, placebo-controlled trial, 39 subjects took a drink containing either 100 mg of HWE or a placebo for 12 weeks during the pollen season. Nasal symptoms (sneezing attacks, nasal discharge, and nasal obstruction) were assessed from the subjects' diaries. A clinical examination and blood sampling were carried out before and 4, 8 and 12 weeks after the initiation of treatment. As a result, a significant difference was observed in the symptom score and in the symptom-medication score 10 weeks after the intervention in comparison with the placebo group. Improvements were observed in nasal swelling, nasal color, amount of nasal discharge, and characteristics of nasal discharge in the intervention group 12 weeks after the treatment. No significant eosinophil infiltration into the nasal discharge was apparent in the intervention group throughout the study period, although it was observed in the placebo group. These findings indicate that an oral administration of HWE may be effective in alleviating the allergic symptoms related to JCPsis. 相似文献
996.
Ishii T Masuzaki H Tanaka T Arai N Yasue S Kobayashi N Tomita T Noguchi M Fujikura J Ebihara K Hosoda K Nakao K 《FEBS letters》2007,581(3):349-354
Macrophage infiltration in obese adipose tissue provokes local inflammation and insulin resistance. Evidence has accumulated that activation of 11beta-HSD1 in adipocytes is critically involved in dysfunction of adipose tissue. However, the potential role of 11beta-HSD1 in macrophages still remains unclear. We here demonstrate that a murine macrophage cell line, J774.1 cells expressed 11beta-HSD1 mRNA and reductase activity, both of which were augmented by lipopolysaccharide (LPS)-induced cell activation. Three kinds of pharmacological inhibition of 11beta-HSD1 in LPS-treated macrophages significantly suppressed the expression and secretion of interleukin 1beta, tumor necrosis factor alpha or monocyte chemoattractant protein 1, thereby highlighting a novel role of 11beta-HSD1 in pro-inflammatory properties of activated macrophages. 相似文献
997.
Watanabe J Chou KJ Liao JC Miao Y Meng HH Ge H Grijalva V Hama S Kozak K Buga G Whitelegge JP Lee TD Farias-Eisner R Navab M Fogelman AM Reddy ST 《The Journal of biological chemistry》2007,282(32):23698-23707
Studies in both mice and humans suggest that the anti- or proinflammatory nature of high density lipoprotein (HDL) may be a more sensitive predictor of risk for coronary heart disease events. In this study, we report the identification and characterization of two proteins (m/z 14,900 and 15,600) that are most dramatically associated with HDL in mouse models of atherosclerosis. Mass spectral analyses of proinflammatory HDL identified the two peaks to be hemoglobin (Hb) alpha and beta chains, respectively, with no apparent post-translational modification. Biochemical analysis confirmed the differential association of Hb with HDL from hyperlipidemic mice. We further show that HDL-associated Hb is predominantly in the oxyHb form with distinct physical and chemical properties. Furthermore oxyHb-containing proinflammatory HDL potently consumed nitric oxide and contracted arterial vessels ex vivo. Moreover Hb also was found differentially associated with HDL from coronary heart disease patients compared with healthy controls. Our data suggest that Hb contributes to the proinflammatory nature of HDL in mouse and human models of atherosclerosis and may serve as a novel biomarker for atherosclerosis. 相似文献
998.
999.
DEAR1, a transcriptional repressor of DREB protein that mediates plant defense and freezing stress responses in Arabidopsis 总被引:3,自引:0,他引:3
Tomokazu Tsutsui Wataru Kato Yutaka Asada Kaori Sako Takeo Sato Yutaka Sonoda Satoshi Kidokoro Kazuko Yamaguchi-Shinozaki Masanori Tamaoki Keita Arakawa Takanari Ichikawa Miki Nakazawa Motoaki Seki Kazuo Shinozaki Minami Matsui Akira Ikeda Junji Yamaguchi 《Journal of plant research》2009,122(6):633-643
1000.
Shimoda T Kishimoto H Takabayashi J Amano H Dicke M 《Experimental & applied acarology》2009,47(2):111-120
Anti-predator defenses provided by complex webs of Tetranychus mites can severely impede the performance of generalist predatory mites, whereas this may not be true for specialist predatory
mites. Although some specialist predatory mites have developed morphological protection to reduce the adverse effects of complex
webs, little is known about their behavioral abilities to cope with the webs. In this study, we compared thread-cutting behavior
of three specialist predatory mites, Phytoseiulus persimilis, Neoseiulus
womersleyi and N. californicus, exhibited inside the complex web of T. urticae. No major difference was observed among them in the basic pattern of this behavior, using chelicerae and palps, and in the
number of silken threads severed while moving inside the web. These results and observations suggest that each predator species
cut many sticky silken threads to move inside the complex web without suffering from serious obstruction.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献