Behavior and mutation of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis> in <Emphasis Type="Italic">Solanum toxicarium</Emphasis> grown in aseptic culture     

Taro Mori  Katsumi Ozaki  Hiromi Matsusaki  Naotaka Matsuzoe 《Journal of General Plant Pathology》2007,73(2):142-146

To study the behavior and mutation of Ralstonia solanacearum in Solanum toxicarium, which is resistant to bacterial wilt, S. toxicarium was grown in aseptic culture and inoculated with R. solanacearum. Although 60%–80% of the inoculated plants were wilting after 2 to 3 days, most wilted plants had recovered by 20 days after inoculation. The pathogen was reisolated from over 98% of inoculated plant stems, but the percentage of recovery decreased the closer the isolation sites were toward the upper stem sections. Three colony types, characterized as fluidal white, nonfluidal red, and a mixture of fluidal white and nonfluidal red, were reisolated from the stems. Nonfluidal red colonies were less virulent on tomato plants than fluidal white colonies.  相似文献   

Phagocytotic activation of muscularis resident macrophages inhibits smooth muscle contraction in rat ileum     

Sato K  Torihashi S  Hori M  Nasu T  Ozaki H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(10):1053-1060

Intestinal muscularis resident macrophages distributed in myenteric region may play an important role in the immunological host defense against infection. In this study, we investigated the phagocytic stimulation of resident macrophages on cyclooxygenase-2 (COX-2) expression and smooth muscle contraction in the small intestine of rat. After the injection of FITC-dextran to rat, phagocytosed macrophages could be detected in the myenteric plexus. FITC-positive macrophages were also immunostained with COX-2 antibody. The number of COX-2 immunopositive cells increased in a time-dependent manner reaching its maximum at 4 hr after the injection, which then decreased gradually but considerable number of cells were still remained on 7 days. The injection of FITC-dextran, however, did not change the population of ED2-positive resident macrophages even on 7 days. Production of PGE2 was significantly higher in the dextran treated tissue as compared to control tissue. In the smooth muscle tissue phagocytosed dextran, carbachol-induced contraction was significantly decreased. The suppression of the carbachol-induced contraction was completely restored by COX inhibitor, indomethacin. Finally we demonstrated that, in freshly isolated macrophage cells, addition of dextran induced a slow and sustained increase in intracellular Ca2+ concentration. These results indicate that phagocytotic activation of muscularis resident macrophages induces COX-2 gene expression and then results in production of PGE2 to suppress the smooth muscle contractile activity.  相似文献   

Carbamate-induced flowering in asparagus (Asparagus officinalis L.) seedlings: optimization of treatment and cultivar variation in flowering response and pollen germination     

Yukio Ozaki  Tomoko Kurahashi  Tomoko Tashiro  Hiroshi Okubo 《Euphytica》1999,110(2):77-83

Optimal carbamate treatment conditions were studied for flower induction in seedlings of an asparagus cultivar ‘Mary Washington 500 W’. Flower induction was most accelerated by soaking seeds in 50 mg l⁻¹ carbamate solution for 12 days at 25 ^°C under the fluorescent light. Longer exposure to carbamate over a 12 day period induced a higher percentage of seedlings to flower. A higher percentage of flowering seedlings were male. Flower induction frequency among seven cultivars through carbamate treatment widely ranged from 13 to 67%. ‘Geynlim’, ‘Mary Washington 500 W’ and ‘Welcome’ exhibited a high percentage of flowering seedlings, while ‘Larac’ and ‘Vulkan’ showed low values. Only male flowers were induced in all-male cultivars. Variation in pollen germination was found within all cultivars. ‘Geynlim’, ‘Cito’ and ‘Mary Washington 500 W’ showed high values of average pollen germination. Application of carbamate compound to induce flower production can rapidly produce homogenic cultivars which include both sexes. This is necessary for genetic studies and breeding purposes. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Appearance of albino seedlings and ptDNA inheritance in interspecific hybrids of azalea   总被引：1，自引：1，他引：0  

K. Ureshino  I. Miyajima  Y. Ozaki  N. Kobayashi  A. Michishita  M. Akabane 《Euphytica》1999,110(1):61-66

PCR-RFLP analysis was conducted to clarify the relationship between the leaf color of progenies and their ptDNA inheritance in interspecific three-way crosses, (Rhododendron kiusianum × R. eriocarpum) × R. japonicum f. flavum. All albino progenies contained maternal ptDNA, whereas green and pale-green progenies contained paternal ptDNA. Sectorial chimeric progenies, of which the leaf and shoot color was turned from green to albino during the culture, contained both maternal and paternal ptDNA in green segments and maternal ptDNA in albino segments. These results suggest that albino progenies are caused by the incompatibility between plastome from F₁ hybrids of R. kiusianum × R. eriocarpum and nuclear genome from R. japonicum f. flavum. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Lipid content and fatty acid composition of muscle,liver, ovary and eggs of captive-reared and wild silver Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis> during artificial maturation     

Yuichi Ozaki  Hidehiro Koga  Takako Takahashi  Shinji Adachi  Kohei Yamauchi 《Fisheries Science》2008,74(2):362-371

ABSTRACT:   Changes in lipid content and fatty acid composition of muscle, liver and ovary of captive-reared and wild silver Japanese eel Anguilla japonica were examined during artificial maturation induced by salmon pituitary homogenate (SPH) injections. Although the relative levels of n-3 and n-6 highly unsaturated fatty acids (HUFA) in liver and ovary were higher than in muscle in both captive and wild silver eels before SPH injection, these tended to decrease with maturation. The relative levels of n-6 HUFA in muscle, liver, ovary and eggs of wild silver eels were remarkably higher than those in captive eels. Therefore, we attempted to alter the ratio of n-6 HUFA in eggs by feeding eels a diet supplemented with linoleic acid-rich plant oil. Although the percentage of n-6 polyunsaturated fatty acids to total fatty acids in eggs of eels fed the supplemented diet was similar to wild silver eels, the percentage of n-6 HUFA remained remarkably lower than in wild silver eels. Hence, it appears that the supplemented diet affected the fatty acid composition of eggs, but did not result in much conversion of linoleic acid to its higher homologs in eels.  相似文献   

Dietary utility of enzyme-treated fish meal for juvenile Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis>     

Seung-Cheol Ji  Osamu Takaoka  Amal Kbiswas  Manabu Seoka  Keita Ozaki  Jun Kohbara  Masaharu Ukawa  Sadao Shimeno  Hidetsuyo Hosokawa  Kenji Takii 《Fisheries Science》2008,74(1):54-61

ABSTRACT:   In order to develop an artificial diet, the dietary utility of enzyme-treated fish meal was investigated for juvenile Pacific bluefin tuna Thunnus orientalis (PBT). Diets containing each 63% of Chilean fish meal (FM), enzyme-treated Chilean fish meal (EC) and enzyme-treated Peruvian fish meal (EP), with 10% bonito oil and raw sand lance Ammodytes personatus (SL) were fed to juvenile tuna six times per day for one week. In a different trial, diets EC and SL were fed to tuna six times per day for 2 weeks. Only diet EC sustained similar growth or caused lower survival and higher feed efficiency, hepato- and enterosomatic indices and final carcass lipid content as compared to those of SL. Diets FM and EP led to lower specific growth rate (SGR) but similar feed efficiency, survival and hepatosomatic index, yet higher enterosomatic index. Moreover, PBT fed diet EC for 2 weeks led to similar growth performance but higher final carcass and hepatic lipid contents, and plasma cholesterol and phospholipid levels than those fed SL. Carcass fatty acid composition of diet EC group had lower 20:5  n -3 and 22:6  n -3 levels than the SL group. These results revealed that EC, as a suitable dietary protein source, could sustain growth of PBT, while dietary bonito oil led to higher carcass lipid but lower accumulation of n -3 highly unsaturated fatty acids.  相似文献   

Immunohistochemical changes in production of pituitary hormones during artificial maturation of female Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis>     

Yuichi Ozaki  Koichi Ishida  Koji Saito  Kazuhiro Ura  Shinji Adachi  Kohei Yamauchi 《Fisheries Science》2007,73(3):574-584

ABSTRACT:   Specific antibodies against follicle-stimulating hormone β subunit (FSHβ), prolactin (PRL), and somatolactin (SL) of the Japanese eel Anguilla japonica were produced. These antibodies, as well as antibodies against luteinizing hormone β subunit (LHβ) and growth hormone (GH) produced previously, were used to examine changes in the production of pituitary hormones in female eels during maturation induced by salmon pituitary homogenate (SPH) injection. Immunohistochemical observations showed a decrease in FSH production after SPH injection, suggesting that SPH inhibits FSH production. In contrast, LH production increased markedly with maturation. The number of GH producing cells decreased gradually during maturation, possibly because of inhibition by exogenous GH present in the SPH and/or endogenous insulin-like growth factor-I produced by the stimulation of salmon GH. Although changes in the number of PRL producing cells with maturation were not evident, the number of SL producing cells showed a peak at the late vitellogenic stages, and thereafter decreased to the migratory nucleus stage. These results suggest that GH and SL are involved in sexual maturation in SPH injected eels, as in other fishes.  相似文献   

超临界CO₂提纯鱼油中二十碳五烯酸组分的试验研究   总被引：10，自引：2，他引：10  

陈钧  铃木启正  阿尻雅文  新井邦夫 《农业工程学报》1996,12(2):152-157

采用附加有精馏柱的间歇式小型超临界ＣＯ₂萃取试验装备，试验研究了鱼油中二十碳五烯酸（ＥＰＡ）组分的分离提纯。为改善气液接触，萃取器内使用了转动不锈钢箔团，精馏柱内充填了Ｄｉｘｏｎ环。为获得高纯度ＥＰＡ，采用了逐步升高萃取压力，并保持精馏柱自底部至顶部的线性温度梯度的试验方法  相似文献   

Insect antifeedant activity of flavones and chromones against Spodoptera litura   总被引：2，自引：0，他引：2  

Morimoto M  Tanimoto K  Nakano S  Ozaki T  Nakano A  Komai K 《Journal of agricultural and food chemistry》2003,51(2):389-393

The antifeedant polymethylated flavones 5-hydroxy-3,6,7,8,4'-heptamethoxyflavone, 5-hydroxy-3,6,7,8-tetramethoxyflavone, and 5,6-dihydroxy-3,7-dimethoxyflavone have been isolated from the cudweed, Gnaphalium affine D. Don (Compositae). These flavonoids and authentic analogues showed insect antifeedant activity against the common cutworm (Spodoptera litura F.). In a previous paper, it was suggested that there was no substituent on the B-ring of the flavonoid for the beneficial antifeedant activity against the common cutworm. These flavonoids having a phenyl group as the B-ring and the chromone as elimination of the B-ring from the flavonoids were used to test the hypothesis of the previously described B-ring effect. The known fact is that Sculletaria baicarensis (Rutaceae) produced the 2-phenyl flavone. Test compounds and their methylated derivatives were prepared from this material for the structure-activity relationship (SAR) study of insect antifeedant activity. In spite of the 2-phenyl flavonoids, some tested compounds did not show any insect antifeedant activity against the common cutworm, although these inactive flavonoids were deficient in the 6-substituent group on the A-ring of the flavonoid. This 6-position-substituted derivative almost showed strong insect antifeedant activity against common cutworm. Moreover, the tested flavonoids having a hydroxyl group as a substituent on any of the positions tended to increase the activity. These results suggested the importance of the 6-position substitution on the flavonoid; however, hydrophilic substituents decreased the activity. Baicalein (5,6,7-trihydroxyflavone) derivatives did not show any activity despite having the 6-substituent derivative. Although the activity of some chromones increased the activity of the flavone, the bulky B-ring was a disadvantage for the antifeedant activity. It was suggested that the charge on C(3) and C(5) of the flavonoid was important for the biological activity. Additionally, an adequate hydrogen bonding property, which is different from lipophilicity, was an advantage for the activity on the basis of a QSAR analysis.  相似文献   

Screening for antioxidant activity in edible plant products: comparison of low-density lipoprotein oxidation assay, DPPH radical scavenging assay, and Folin-Ciocalteu assay     

Katsube T  Tabata H  Ohta Y  Yamasaki Y  Anuurad E  Shiwaku K  Yamane Y 《Journal of agricultural and food chemistry》2004,52(8):2391-2396

Oxidation of low-density lipoprotein (LDL) has been implicated in atherogenesis. Antioxidants that prevent LDL from oxidizing may reduce atherosclerosis. This study investigated LDL antioxidant activity in edible plant products for development of dietary supplementation to prevent atherosclerosis. Fifty-two kinds of edible plants were extracted using 70% aqueous ethanol solution, and the antioxidant activity of the extracts, which inhibit human LDL oxidation induced by copper ion, was determined on the basis of the oxidation lag time and represented as epigallocatechin 3-gallate equivalent. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic content were also measured for comparisons with antioxidant activity in LDL. Plant products showing the greatest activity in LDL oxidation assay were akamegashiwa (Mallotus japonicus) leaf, Japanese privet (Ligustrum japonicum) leaf, green tea [Camellia sinensis (L.) O. Kuntze], and astringent persimmon (Diospyros kaki). The present study revealed high levels of LDL antioxidant activity in plant products for which such activity levels are underestimated in the DPPH radical scavenging assay and Folin-Ciocalteu assay.  相似文献