Regulation of elicitin-induced ethylene production in suspension-cultured tobacco BY-2 cells     

Dirk Schenke  Kana Naito  Kazuhiro Toyoda  Yoshishige Inagaki  Tomonori Shiraishi  Yuki Ichinose 《Journal of General Plant Pathology》2005,71(4):273-279

INF1 elicitin, a proteinaceous elicitor produced by Phytophthora infestans, induces a hypersensitive response in tobacco BY-2 cells. In response to elicitin, tobacco cells produce both reactive oxygen species (ROS) and ethylene (ET). To investigate the regulation of elicitin-induced ET production, we pharmacologically analyzed the effects of several chemicals on ET production. Inhibitors of ROS generation or ROS chelators efficiently inhibited ET production, whereas simultaneous treatment of a superoxide anion-generating system with salicylhydroxamic acid recovered ET production. In an in vitro experiment, superoxide anion was necessary and sufficient for conversion of 1-aminocyclopropane-1-carboxylate (ACC) to ET because ET was produced from ACC solely in the presence of the superoxide-generating chemical KO₂. ET production was also inhibited by lipoxygenase (LOX) inhibitors, indicating a possible involvement of LOX-mediated generation of superoxide anion and ET production itself. Furthermore, elicitin-induced ET production was completely inhibited by the protein synthesis inhibitor cycloheximide but recovered after exogenous application of ACC, indicating that de novo protein synthesis is required for ACC accumulation, leading to ET production. We also investigated the effects of several phytohormones on elicitor-induced ET production and discuss their role in the defense response.  相似文献   

Expression pattern of melanin biosynthesis enzymes during infectious morphogenesis of <Emphasis Type="Italic">Colletotrichum lagenarium</Emphasis>     

Gento Tsuji  Seiji Tsuge  Tomonori Shiraishi  Yasuyuki Kubo 《Journal of General Plant Pathology》2003,69(3):169-175

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Orally administered conjugated linoleic acid ameliorates allergic dermatitis induced by repeated applications of oxazolone in mice          下载免费PDF全文

Tomonori Nakanishi  Yuzo Tokunaga  Masao Yamasaki  Laurie Erickson  Satoshi Kawahara 《Animal Science Journal》2016,87(12):1554-1561

Conjugated linoleic acid (CLA) is one of the constituents of animal products with possible health benefits such as anti‐carcinogenic and anti‐obesity effects. In this study, we investigated the immunomodulatory effects of CLA using a mouse model of allergic dermatitis. Mice were orally administered either a CLA mixture containing equal amounts of 9c, 11 t‐CLA and 10 t, 12c‐CLA, or high linoleic acid safflower oil, and allergic dermatitis was induced on the ear by repeated topical applications of oxazolone. Oral administration of the CLA mixture but not the high linoleic safflower oil attenuated the symptoms of allergic dermatitis in both ear weights and clinical scores. This effect was associated with decreased levels of ear interleukin‐4 (IL‐4) and plasma immunoglobulin E. The immunomodulatory effects of the CLA isomers were compared by an in vitro cytokine production assay. The results showed that 9c, 11 t‐CLA, the most predominant isomer in animal products, significantly inhibited IL‐4 and interferon‐γ production from mouse splenocytes with similar potency to 10 t, 12c‐CLA. These findings suggest that CLA, a constituent of animal products, has a potentially beneficial effect for amelioration of allergic dermatitis.  相似文献   

A pea NTPase, PsAPY1, recognizes signal molecules from microorganisms     

Akinori Kiba  Kazuhiro Toyoda  Kazuaki Yoshioka  Kami Tsujimura  Hirotaka Takahashi  Yuki Ichinose  Tadahiro Takeda  Toshiaki Kato  Tomonori Shiraishi 《Journal of General Plant Pathology》2006,72(4):238-246

Apyrases (E.C.3.6.1.5; NTP-NDPases) are distributed in the cytosol, nuclei, cytoskeleton, and on the surface of plant cells. Some may play an important role in signal transduction from exogenous stimuli. We previously found a protein of ca. 55-kDa (CWP-55) in an ATPase-rich fraction from the pea cell wall bound to the elicitor and supprescins (suppressors of defense) from pea pathogen Mycosphaerella pinodes. We cloned the cDNA of CWP-55 that coincided with PsAPY1, one of two NTPase clones in a pea cDNA library. An analysis with a green fluorescent protein fusion protein indicated that PsAPY1 was distributed in the cell wall, nucleus, and cytoplasm. The recombinant PsAPY1 expressed in Escherichia coli had ATP-hydrolyzing activity responsive not only to the elicitor and supprescins from the pea pathogen but also to other elicitors such as a bacterial harpin, a yeast extract, and a synthetic glycopeptide. Biotinylated fungal signal molecules were bound to the recombinant PsAPY1 specifically. Resonant mirror detection confirmed such binding characteristics of PsAPY1. Based on these results, we discuss the role of cell-wall-bound NTPases in recognizing and responding to microorganisms on the cell wall surface.  相似文献   

A preliminary study to understand the transport process for the eggs and larvae of Japanese Pacific walleye pollock Theragra chalcogramma using particle-tracking experiments based on a high-resolution ocean model     

Hiroshi Kuroda  Daisuke Takahashi  Humio Mitsudera  Tomonori Azumaya  Takashi Setou 《Fisheries Science》2014,80(2):127-138

We developed a realistic 1/50° high-resolution ocean model capable of resolving submesoscale variability, and performed particle-tracking experiments based on this ocean model to identify elements that significantly affect the transport of the eggs and larvae of the Japanese Pacific walleye pollock Theragra chalcogramma into Funka Bay. The high-resolution model reproduced representative features of the oceanographic conditions of the main spawning area and season. A comparison of particle-tracking experiments performed under the passive transport condition based on high-resolution (1/50°) and low-resolution (1/10°) ocean models showed that high-resolution modeling is essential in order to realistically simulate the transport process. In this regard, however, the vertical motion of particles cannot be explained by the passive transport condition, as it leads to unrealistically deep sinking of particles in the simulation. Turning our attention to feasible non-passive transport conditions, we then incorporated the buoyancy motion of particles and conducted additional experiments that mainly differed in the particle density adopted. We clarified that buoyancy is an important factor in the retention of particles near the sea surface, and that the ratio of the particles that remain in Funka Bay to the number of particles released is sensitive to the vertical motions/positions of the particles, implying that it is necessary to model this vertical motion more accurately by incorporating more realistic biological processes or a statistical distribution into the particle-tracking model.  相似文献   

Estimating water use of a black locust plantation by the thermal dissipation probe method in the semiarid region of Loess Plateau, China   总被引：1，自引：0，他引：1  

Yi-Long Wang  Guo-Bin Liu  Tomonori Kume  Kyoichi Otsuki  Norikazu Yamanaka  Sheng Du 《Journal of Forest Research》2010,15(4):241-251

Black locust (Robinia pseudoacacia) is a major reforestation species in the semiarid region in the Loess Plateau of China. There has been increasing concern about the sustainability of the plantations because of their possible high water-use. This study was, accordingly, undertaken to quantify the stand-scale water use of a middle-aged black locust plantation in the region. The thermal dissipation probe method was applied to 27 trees to measure sap flux densities in an experimental plot during the growing season of 2008. The monoculture stand has a basal area of 23.3 m² ha^?1 and a maximum plant area index (PAI) of 2.89. Sapwood areas were estimated by use of a regressive relationship with the diameter at breast height (DBH) for scaling up of stand transpiration. The results showed that DBH could be a good predictor of sapwood area of individual trees. The diurnal cycles of average sap flux densities differed among DBH classes. Daily transpiration can be predicted from mean daily daytime vapor pressure deficit (VPD_m) using a fitted exponential saturation model. Model variables were different among seasons, probably owing to different soil water conditions and leaf phenology. By using the derived model for each month, stand canopy transpiration over the growing season was estimated to be 73.8 mm, with an average daily value of 0.41 mm day^?1 and a maximum of 0.89 mm day^?1. The relatively small estimates of stand transpiration might be attributed to low PAI and sap wood area of the middle-aged stand.  相似文献   

Overexpression of a fungal laccase gene induces nondehiscent anthers and morphological changes in flowers of transgenic tobacco     

Zannatul Nasrin  Misato Yoshikawa  Yuki Nakamura  Shahanara Begum  Satoshi Nakaba  Mikiko Uesugi  Yuriko Osakabe  Tomonori Sonoki  Kanna Sato  Ryo Funada  Yosuke Iimura  Yoshihiro Katayama  Shinya Kajita 《Journal of Wood Science》2010,56(6):460-469

Laccases play important roles in the development of fruiting bodies and in lignin degradation by basidiomycetes. In this study, we present novel phenotypes of transgenic tobacco plants with a chimeric gene for fungal laccase under the control of the cauliflower mosaic virus 35S promoter. At the flowering stage, the transgenic plants that produced recombinant laccase had brownish anthers instead of the greenish anthers of wild-type plants. The brownish anthers exhibited male sterility with a nondehiscent phenotype at varying frequencies. The frequency of nondehiscence depended on the temperature at which plants were cultivated and it was higher at 24°C than at 29°C. The cell wall structures of transgenic anther tissues were almost the same as in the wild type, but the stomium was severely deformed, and abnormal components were apparent in cells of the endothecium and epidermis. Furthermore, the pattern of deposition of flavonoids in the transgenic anther epidermis differed from the wild-type pattern. The expression of laccase also induced other phenotypic changes in the flowers of transgenic plants, namely, increased petal number, fused and petaloid stamens, and doubling of floral organs. These results indicate that the ectopic expression of laccase influences various aspects of flower development.  相似文献   

Neuronal activation modulates enhancer activity of genes for excitatory synaptogenesis through de novo DNA methylation     

Tomonori KAMEDA  Hideyuki NAKASHIMA  Takumi TAKIZAWA  Fumihito MIURA  Takashi ITO  Kinichi NAKASHIMA  Takuya IMAMURA 《The Journal of reproduction and development》2021,67(6):369

Post-mitotic neurons do exhibit DNA methylation changes, contrary to the longstanding belief that the epigenetic pattern in terminally differentiated cells is essentially unchanged. While the mechanism and physiological significance of DNA demethylation in neurons have been extensively elucidated, the occurrence of de novo DNA methylation and its impacts have been much less investigated. In the present study, we showed that neuronal activation induces de novo DNA methylation at enhancer regions, which can repress target genes in primary cultured hippocampal neurons. The functional significance of this de novo DNA methylation was underpinned by the demonstration that inhibition of DNA methyltransferase (DNMT) activity decreased neuronal activity-induced excitatory synaptogenesis. Overexpression of WW and C2 domain-containing 1 (Wwc1), a representative target gene of de novo DNA methylation, could phenocopy this DNMT inhibition-induced decrease in synaptogenesis. We found that both DNMT1 and DNMT3a were required for neuronal activity-induced de novo DNA methylation of the Wwc1 enhancer. Taken together, we concluded that neuronal activity-induced de novo DNA methylation that affects gene expression has an impact on neuronal physiology that is comparable to that of DNA demethylation. Since the different requirements of DNMTs for germ cell and embryonic development are known, our findings also have considerable implications for future studies on epigenomics in the field of reproductive biology.  相似文献   

Fate of pesticides during beer brewing     

Inoue T  Nagatomi Y  Suga K  Uyama A  Mochizuki N 《Journal of agricultural and food chemistry》2011,59(8):3857-3868

The fates of more than 300 pesticide residues were investigated in the course of beer brewing. Ground malt artificially contaminated with pesticides was brewed via steps such as mashing, boiling, and fermentation. Analytical samples were taken from wort, spent grain, and beer produced at certain key points in the brewing process. The samples were extracted and purified with the QuEChERS (Quick Easy Cheap Effective Rugged and Safe) method and were then analyzed by LC-MS/MS using a multiresidue method. In the results, a majority of pesticides showed a reduction in the unhopped wort and were adsorbed onto the spent grain after mashing. In addition, some pesticides diminished during the boiling and fermentation. This suggests that the reduction was caused mainly by adsorption, pyrolysis, and hydrolysis. After the entire process of brewing, the risks of contaminating beer with pesticides were reduced remarkably, and only a few pesticides remained without being removed or resolved.  相似文献   

Nitro-PAHs and PAHs in Atmospheric Particulate Matters and Sea Sediments in Hiroshima Bay Area, Japan     

Noriatsu Ozaki  Nobuya Takemoto  Tomonori Kindaichi 《Water, air, and soil pollution》2010,207(1-4):263-271

Atmospheric and sea sediment concentrations were measured for eight nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and three unsubstituted PAHs in a suburban area and sea sediments in the Hiroshima Bay watershed area, Japan, from July to December, 2006 (atmospheric particulate matter) and in September and November, 2004 (sea sediments). Atmospheric concentration was higher in winter than summer for both nitro-PAHs and PAHs. Concentrations in sea sediments were less than 10%, and pattern was similar to those of atmospheric particles. Several combustion emission sources were also measured, and the 1-NP/Pyr ratio was compared to environmental values. The ratio of atmospheric and sea sediments were significantly lower than diesel particulate matters. Further, the vehicle emission loading and sea sedimentation loading was evaluated in this watershed area, and from the comparison, the existence of other important sources PAHs were suggested.  相似文献