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ABSTRACT: Salicylic acid (SA), yeast elicitor (YEL), and chitosan (CHT) induced stomatal closure in Arabidopsis wild-type and aba2-2 plants, induced stomatal closure in fluridon-treated wild-type plants, and induced stomatal closure in aos mutants. These results suggest that neither endogenous abscisic acid nor endogenous jasmonic acid is involved in SA-, YEL-, or CHT-induced stomatal closure.
Bioscience Biotechnology and Biochemistry 05/2013; · 1.28 Impact Factor
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ABSTRACT: Isothiocyanates, nitriles, and thiocyanates are degradation products of glucosinolates in crucifer plants. In this study, we investigated the stomatal response to allyl isothiocyanate (AITC), 3-butenenitrile (3BN), and ethyl thiocyanate (ESCN) in Arabidopsis. AITC, 3BN, and ESCN induced stomatal closure in the wild type and the atrbohD atrbohF mutant. Stomatal closure was inhibited by catalase and salicylhydroxamic acid (SHAM). The degradation products induced extracellular reactive oxygen species (ROS) production in the rosette leaves, and intracellular ROS accumulation, NO production, and cytosolic free calcium concentration ([Ca(2+)]cyt) oscillations in guard cells, which were inhibited by SHAM. These results suggest that glucosinolate degradation products induce stomatal closure accompanied by extracellular ROS production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and [Ca(2+)]cyt oscillation in Arabidopsis.
Bioscience Biotechnology and Biochemistry 05/2013; · 1.28 Impact Factor
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ABSTRACT: We recently demonstrated that endogenous abscisic acid (ABA) is involved in methyl jasmonate (MeJA)-induced stomatal closure in Arabidopsis thaliana. In this study, we investigated whether endogenous ABA is involved in MeJA-induced reactive oxygen species (ROS) and nitric oxide (NO) production and cytosolic alkalization in guard cells using an ABA-deficient Arabidopsis mutant, aba2-2, and an inhibitor of ABA biosynthesis, fluridon (FLU). The aba2-2 mutation impaired MeJA-induced ROS and NO production. FLU inhibited MeJA-induced ROS production in wild-type guard cells. Pretreatment with 0.1μM ABA, which does not induce stomatal closure in the wild type, complemented the insensitivity to MeJA of the aba2-2 mutant. However, MeJA induced cytosolic alkalization in both wild-type and aba2-2 guard cells. These results suggest that endogenous ABA is involved in MeJA-induced ROS and NO production but not in MeJA-induced cytosolic alkalization in Arabidopsis guard cells.
Journal of plant physiology 04/2013; · 2.50 Impact Factor
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ABSTRACT: BACKGROUND: In this study, whole krill oil (WKO) and phospholipid-type krill oil (PKO) with different lipid composition were prepared. The effects of KO intake on plasma cholesterol and glucose levels in Wistar rats fed a high-cholesterol diet (HCD) were investigated. RESULTS: WKO contained 37.63% triglycerides, 48.37% phospholipids, 13.54% free fatty acids and 0.66% cholesterol, whereas the corresponding values for PKO were 0.59, 69.80, 28.53 and 1.09% respectively. Meanwhile, PKO contained much more polyunsaturated fatty acids (PUFA, 37.76%) than WKO (28.36%). After 4 weeks of HCD consumption, plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and glucose increased significantly, but that of high-density lipoprotein cholesterol (HDL-C) decreased significantly. The intake of PKO and WKO for 4 weeks caused a significant reduction in body weight gain and plasma levels of TC and LDL-C in HCD-fed rats. Compared with WKO, PKO was more effective in decreasing plasma TC and LDL-C levels. CONCLUSION: PKO showed better overall cholesterol-lowering effects than WKO, which may be due to its higher n-3 PUFA levels. © 2013 Society of Chemical Industry.
Journal of the Science of Food and Agriculture 01/2013; · 1.44 Impact Factor
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ABSTRACT: Glutathione (GSH) is involved in abscisic acid (ABA)- and methyl jasmonate (MeJA)-induced stomatal closure in Arabidopsis thaliana. In this study, we examined the effects of GSH-decreasing chemicals, p-nitrobenzyl chloride (PNBC), iodomethane (IDM), and ethacrynic acid (EA), on ABA- and MeJA-induced stomatal closure in Arabidopsis. Treatments with PNBC, IDM, and EA decreased GSH contents in guard cells. Depletion of GSH by PNBC and IDM enhanced ABA- and MeJA-induced stomatal closure and inhibition of light-induced stomatal opening by ABA, whereas EA did not enhance either ABA- and MeJA-induced stomatal closure or inhibition of light-induced stomatal opening by ABA. Depletion of GSH did not significantly increase the production of the reactive oxygen species (ROS), cytosolic alkalization, or cytosolic Ca(2+) oscillation induced by ABA and MeJA. These results indicate that depletion of GSH enhances ABA- and MeJA-induced stomatal closure without affecting ROS production, cytosolic alkalization, or cytosolic Ca(2+) oscillation in guard cells of Arabidopsis.
Bioscience Biotechnology and Biochemistry 11/2012; · 1.28 Impact Factor
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ABSTRACT: Chitosan (CHT)-induced stomatal closure was inhibited by an MAPKK inhibitor, PD98059, and was impaired in mpk9 mpk12 but not in mpk9 or mpk12. CHT induced the production of reactive oxygen species, cytosolic alkalization, and cytosolic Ca(2+) oscillation in mpk9 mpk12. These results suggest that MPK9 and MPK12 are involved in CHT-induced stomatal closure.
Bioscience Biotechnology and Biochemistry 09/2012; 76(9):1785-7. · 1.28 Impact Factor
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ABSTRACT: Salinity significantly increased trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS) uptake and decreased the K(+)/Na(+) ratio in salt-sensitive rice (Nipponbare) but did not markedly in salt-tolerant rice (Pokkali). Proline and glycinebetaine (betaine) suppressed the increase in PTS uptake and the decrease in the K(+)/Na(+) ratio in Nipponbare, but did not affect PTS uptake or the K(+)/Na(+) ratio in Pokkali.
Bioscience Biotechnology and Biochemistry 08/2012; 76(8):1568-70. · 1.28 Impact Factor
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ABSTRACT: Methylglyoxal (MG) is one of the aldehydes accumulated in plants under environmental stress. Cytosolic ascorbate peroxidase (cAPX) plays a key role in the protection of cells from oxidative damage by scavenging reactive oxygen species in higher plants. A cDNA encoding cAPX, named NtcAPX, was isolated from Nicotiana tabacum. We characterized recombinant NtcAPX (rNtcAPX) as a fusion protein with glutathione S-transferase to investigate the effects of MG on APX. NtcAPX consists of 250 amino acids and has a deduced molecular mass of 27.5 kDa. The rNtcAPX showed a higher APX activity. MG treatments resulted in a reduction of APX activity and modifications of amino groups in rNtcAPX with increasing K(m) for ascorbate. On the contrary, neither NaCl nor cadmium reduced the activity of APX. The present study suggests that inhibition of APX is in part due to the modification of amino acids by MG.
Journal of Biochemical and Molecular Toxicology 06/2012; 26(8):315-21. · 1.38 Impact Factor
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ABSTRACT: Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.
Bioscience Biotechnology and Biochemistry 05/2012; 76(5):900-5. · 1.28 Impact Factor
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ABSTRACT: We investigated the mechanism of selenium (Se) tolerance using an Arabidopsis thaliana knockout mutant of a sulfate transporter, sultr1;2. Se stress inhibited plant growth, decreased chlorophyll contents, and increased protein oxidation and lipid peroxidation in the wild type, whereas the sultr1;2 mutation mitigated damage of these forms, indicating that sultr1;2 is more tolerant of Se than the wild type is. The accumulation of symplastic Se was suppressed in sultr1;2 as compared to the wild type, and the chemical speciation of Se in the mutant was different from that in the wild type. Regardless of Se stress, the activities of ascorbate peroxidase, catalase, and peroxidase in the mutant were higher than in the wild type, while the activity of superoxide dismutase in the mutant was the same as in the wild type. These results suggest that the sultr1;2 mutation confers Se tolerance on Arabidopsis by decreasing symplastic Se and maintaining antioxidant enzyme activities.
Bioscience Biotechnology and Biochemistry 05/2012; 76(5):993-8. · 1.28 Impact Factor
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ABSTRACT: A water-soluble polysaccharide, SVP-2, was obtained from Patinopecten yessoensis viscera. Its major structural features were elucidated using composition analysis, methylation analysis, periodate oxidation
and Smith degradation, partial acid hydrolysis, and NMR spectroscopy. The results indicated that SVP-2, with an average molecular
weight of 170kDa, was composed of rhamnose, fucose, arabian, xylose, mannose, galactose, and glucose in molar ratios of 1.65:2.54:4.05:5.60:1.48:4.90:1.00.
Furthermore, it could deduce that the backbone of SVP-2 consisted of 1,3,4-linked pyran fucose, 1,3,4-linked pyran galactose,
and 1,3-linked pyran arabian residues.
European Food Research and Technology 05/2012; 229(6):971-974. · 1.57 Impact Factor
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ABSTRACT: Changes of the collagen in sea cucumber (Stichopus japonicas) during cooking were investigated. Crude collagen fibers (CCF) is more sensitive to heat than pepsin-solubilized collagen
(PSC), absorbance at 226–232 nm increased from 60 to 100°C. PSC nearly completely degraded after cooking for 8–10 h, 4–6 h,
1–1.5 h, 40–50 min, and 10–20 min at 60, 70, 80, 90, and 100°C, respectively. Collagen fiber shrinkage, disappearance of periodic
cross striation, complete denaturation, and dispersion of denatured fibers at 40, 60, 80 and 100°C, respectively, were demonstrated
by transmission electron microscope (TEM). Above results might be instructional for sea cucumber processing and collagen usage.
Keywordssea cucumber (Stichopus japonicus)–collagen–cooking
Food science and biotechnology 05/2012; 20(4):1137-1141. · 0.49 Impact Factor
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ABSTRACT: Cathepsin B from the gut of sea cucumber (Stichopus japonicas) was purified 81-fold with a 3% recovery by ammonium sulfate fractionation and a series chromatography on DEAE Sepharose
CL-6B, Sephadex G-75, and TSK-Gel 3000 SWxl. The purified protein appeared as a single band on Native-PAGE but showed 2 bands
of 23 and 26 kDa on SDS-PAGE. The optimum activity was found at pH 5.5 and 45°C. The enzyme was stable at pH 4.5–6.0 and the
thermal stability was up to 50oC. The enzyme was strongly inhibited by E-64, iodoacetic acid, and antipain, demonstrating
it is a cysteine protease containing sulfhydryl groups. Cu2+, Ni2+, and Zn2+ could strongly inhibit the enzyme activity. The amino acid sequences of the purified enzyme were acquired by mass spectrometer,
which did not show any homology with previously described cathepsins, suggesting it may be a novel member.
Keywordscathepsin B–sea cucumber (Stichopus japonicus)–purification–characterization
Food science and biotechnology 04/2012; 20(4):919-925. · 0.49 Impact Factor
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ABSTRACT: As rich in polyunsaturated fatty acid (PUFA), sea urchin gonad could be used as a potential resource of such type ingredients.
In the present study, lipid was extracted from sea urchin (Strongylocentrotus nudus) gonad, without using organic solvent but using an enzyme-assisted aqueous method and a supercritical carbon dioxide (SC-CO2) method. The yield of lipid extracted was calculated in comparison with the soxhlet extraction using ethyl ether as solvent.
The results showed that enzyme-assisted aqueous extraction allowed recovering 82.0±2.1, 76.0±2.3, 72.9±3.6, and 61.5±1.6%
of sea urchin gonad lipid from the sample hydrolyzed by papain, neutral protease, alkaline protease, and trypsin, respectively.
Meanwhile, a lipid yield of 53.7±2.6% was achieved by SC-CO2 extraction. The lipid obtained was divided into unsaponifiable (sterol) and fatty acid, and analyzed by GC–MS. Results demonstrated
that the compositions of sterol and fatty acid were very similar for samples extracted by different methods. PUFA was the
chief component which accounts for approximately 35% of the total fatty acid.
European Food Research and Technology 04/2012; 230(5):737-743. · 1.57 Impact Factor
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ABSTRACT: Methyl jasmonate (MeJA)-induced stomatal closure is accompanied by the accumulation of hydrogen peroxide (H₂O₂) in guard cells. In this study, we investigated the roles of catalases (CATs) in MeJA-induced stomatal closure using cat mutants cat2, cat3-1 and cat1 cat3, and the CAT inhibitor, 3-aminotriazole (AT). When assessed with 2',7'-dichlorodihydrofluorescein, the reduction of catalase activity by means of mutations and the inhibitor accumulated higher basal levels of H₂O₂ in guard cells whereas they did not affect stomatal aperture in the absence of MeJA. In contrast, the cat mutations and the treatment with AT potentiated MeJA-induced stomatal closure and MeJA-induced H₂O₂ production. These results indicate that CATs negatively regulate H₂O₂ accumulation in guard cells and suggest that inducible H₂O₂ production rather than constitutive elevation modulates stomatal apertures in Arabidopsis.
Journal of plant physiology 04/2012; 169(10):1012-6. · 2.50 Impact Factor
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ABSTRACT: Methylglyoxal (MG) is an oxygenated short aldehyde and a glycolytic intermediate that accumulates in plants under environmental stresses. Being a reactive α-oxoaldehyde, MG may act as a signaling molecule in plants during stresses. We investigated whether MG induces stomatal closure, reactive oxygen species (ROS) production, and cytosolic free calcium concentration ([Ca²⁺](cyt)) to clarify roles of MG in Arabidopsis guard cells. MG induced production of ROS and [Ca²⁺](cyt) oscillations, leading to stomatal closure. The MG-induced stomatal closure and ROS production were completely inhibited by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), but were not affected by an NAD(P)H oxidase mutation, atrbohD atrbohF. Furthermore, the MG-elicited [Ca²⁺](cyt) oscillations were significantly suppressed by SHAM but not by the atrbohD atrbohF mutation. Neither endogenous abscisic acid nor endogenous methyl jasmonate was involved in MG-induced stomatal closure. These results suggest that intrinsic metabolite MG can induce stomatal closure in Arabidopsis accompanied by extracellular ROS production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and [Ca²⁺](cyt) oscillations.
Journal of plant physiology 03/2012; 169(10):979-86. · 2.50 Impact Factor
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ABSTRACT: We investigated the molecular mechanisms underlying phloxine B (PhB)-induced photocytotoxicity in human T lymphocytic leukemia Jurkat cells. In addition to apoptosis-related biochemical events, photo-irradiated PhB generated intracellular reactive oxygen species (ROS), induced phosphorylation of c-Jun-N-terminal kinase (JNK) in an oxidative stress-dependent manner and up-regulated the gene expression of interferon (IFN)-γ, an inducer of diverse apoptosis-related molecules in activated T cells. PhB-induced apoptosis was significantly inhibited by N-acetyl-l-cysteine, but not by catalase, indicating that ROS generation occurred intracellularly, and by SP600125 and AG490, specific inhibitors of JNK and IFN-γ signaling, respectively, confirming their roles in the apoptotic pathway. IFN-γ up-regulation was also inhibited by SP600125, indicating that it was downstream of JNK activation. These results suggest that PhB-induced apoptosis in Jurkat cells partially involves the intracellular oxidative stress-sensitive and T cell-specific IFN-γ pathway. These data present a novel insight into the mechanisms of photocytotoxicity induced by artificial food colorants in human T lymphocytic leukemia cells.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 03/2012; 50(6):1841-7. · 2.99 Impact Factor
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Misugi Uraji,
Takeshi Katagiri,
Eiji Okuma,
Wenxiu Ye,
Mohammad Anowar Hossain,
Choji Masuda,
Aya Miura,
Yoshimasa Nakamura,
Izumi C Mori,
Kazuo Shinozaki, Yoshiyuki Murata
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ABSTRACT: Phospholipase D (PLD) is involved in responses to abiotic stress and abscisic acid (ABA) signaling. To investigate the roles of two Arabidopsis (Arabidopsis thaliana) PLDs, PLDα1 and PLDδ, in ABA signaling in guard cells, we analyzed ABA responses in guard cells using Arabidopsis wild type, pldα1 and pldδ single mutants, and a pldα1 pldδ double mutant. ABA-induced stomatal closure was suppressed in the pldα1 pldδ double mutant but not in the pld single mutants. The pldα1 and pldδ mutations reduced ABA-induced phosphatidic acid production in epidermal tissues. Expression of either PLDα1 or PLDδ complemented the double mutant stomatal phenotype. ABA-induced stomatal closure in both pldα1 and pldδ single mutants was inhibited by a PLD inhibitor (1-butanol ), suggesting that both PLDα1 and PLDδ function in ABA-induced stomatal closure. During ABA-induced stomatal closure, wild-type guard cells accumulate reactive oxygen species and nitric oxide and undergo cytosolic alkalization, but these changes are reduced in guard cells of the pldα1 pldδ double mutant. Inward-rectifying K(+) channel currents of guard cells were inhibited by ABA in the wild type but not in the pldα1 pldδ double mutant. ABA inhibited stomatal opening in the wild type and the pldδ mutant but not in the pldα1 mutant. In wild-type rosette leaves, ABA significantly increased PLDδ transcript levels but did not change PLDα1 transcript levels. Furthermore, the pldα1 and pldδ mutations mitigated ABA inhibition of seed germination. These results suggest that PLDα1 and PLDδ cooperate in ABA signaling in guard cells but that their functions do not completely overlap.
Plant physiology 03/2012; 159(1):450-60. · 6.53 Impact Factor
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ABSTRACT: Pre-treatment with α-tocopherol (α-Toc) potentiated cytotoxicity induction by benzyl isothiocyanate (BITC). Biochemical events related to apoptosis, such as DNA ladder formation and caspase-3 activation, were also enhanced by α-Toc. These results suggest a significant role of the caspase-3 pathway in apoptosis induction regulated by α-Toc in combination.
Bioscience Biotechnology and Biochemistry 02/2012; 76(2):381-3. · 1.28 Impact Factor
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ABSTRACT: In the present study, we examined the toxicity of benzyl ITC (BITC) and its urinary mercapturic acid metabolite (BITC-NAC), using a normal renal proximal tubular cell line, pig LLC-PK1. BITC increased cell death with an IC(50) value of about 7 μM, whereas the cytotoxic effect of BITC-NAC was five times weaker than that of BITC. We observed a significant necrosis of the compounds on LLC-PK1 cells with oxidative stress. In the presence of 5 mM glutathione (GSH), comparable to physiological levels, the cytotoxicity of BITC-NAC as well as BITC was significantly reduced. Furthermore, the increase in intracellular GSH levels by pretreatment with NAC before the BITC treatment resulted in inhibition of the BITC-induced necrotic events as well as intracellular oxidative stress. These results suggest that GSH is a determinant of cellular resistance against the BITC-mediated and oxidative stress-dependent cytotoxicity in renal proximal tubular cells.
Journal of Agricultural and Food Chemistry 02/2012; 60(7):1887-92. · 2.82 Impact Factor
