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   

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   

In situ enumeration and localization of the probiotic <Emphasis Type="Italic">Pediococcus</Emphasis> sp. strain Ab1 in the gut of abalone <Emphasis Type="Italic">Haliotis gigantea</Emphasis>     

Reiji Tanaka  Hiroyuki Mitsuya  Mizuki Aoki  Taeko Miyazaki  Masashi Ootsubo  Peter Bossier 《Fisheries Science》2016,82(3):481-489

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An arabinogalactan-protein from whole grain of Avena sativa L. belongs to the wattle-blossom type of arabinogalactan-proteins     

Esther M. Gllner  Hitomi Ichinose  Satoshi Kaneko  Wolfgang Blaschek  Birgit Classen 《Journal of Cereal Science》2011,53(2):244-249

An arabinogalactan-protein (AGP) from whole grain of oat (Avena sativa L.) has been isolated for the first time by double precipitation with β-glucosyl Yariv reagent and characterized with regard to its polysaccharide and protein part. The large carbohydrate moiety is rich in galactose (63.0% w/w) and arabinose (32.8% w/w) and free of uronic acids. Linkage analysis of AGP and its products obtained by partial acid hydrolysis as well as enzymatic degradation with specific recombinant enzymes revealed that the carbohydrate moiety consists of a 1,3-Galp backbone and is linked in position 6 to short 1,6-Galp chains, terminating in Araf. In the protein part, high contents of alanine, hydroxyproline and serine could be found which are typical for AGPs. The molecular mass of AGP was determined to be 83 kDa. The carbohydrate moieties, released by alkaline degradation of the protein part, had a size of about 7 kDa. Consequently, the overall structure of the AGP from oat could be assigned to be consistent with the wattle-blossom model of AGPs.  相似文献   

Enzymatic solubilization of collagen in the skin of diamond squid Thysanoteuthis rhombus: application of a fungal acid protease     

Shoshi Mizuta  Mayu Nishizawa  Fuuta Sekiguchi  Kazuhiko Matsuo  Yoshihiro Yokoyama  Reiji Yoshinaka 《Fisheries Science》2013,79(5):841-848

Enzymatic solubilization of collagen from the skin tissue of diamond squid Thysanoteuthis rhombus, an underutilized resource in Japan, was attempted using an acid protease from the fungus Rhizopus niveus. This novel approach was compared with the conventional method using porcine pepsin. Both proteases were able to solubilize most of the skin collagen (>90 % of the total collagen) by performing the treatment in 0.5 M acetic acid at 4 °C for 72 h and at an enzyme/substrate ratio (w/w) of 1/10. The SDS-PAGE patterns of the solubilized collagen preparations were quite similar to each other, and two types of collagen (major and minor collagens) were purified from each preparation by cation-exchange column chromatography. These collagen types from the porcine pepsin-solubilized collagen showed similar features to those from the Rhizopus acid protease-solubilized collagen. These results suggest that the Rhizopus acid protease, a protease of non-animal origin, is applicable for solubilizing collagen in the skin of diamond squid.  相似文献   

Temporal fluctuation in the abundance of alginate‐degrading bacteria in the gut of abalone Haliotis gigantea over 1 year          下载免费PDF全文

Reiji Tanaka  Toshiyuki Shibata  Hideo Miyake  Tetsushi Mori  Yutaka Tamaru  Mitsuyoshi Ueda  Peter Bossier 《Aquaculture Research》2016,47(9):2899-2908

In this study, we identified and enumerated alginate‐degrading bacteria in the gut of abalone over 1‐year period. From a total of 360 colonies growing on agar medium enriched with alginate, 251 isolates (70%) had the ability to degrade alginate. In addition, a high number of viable alginate‐degrading bacteria were detected throughout the survey period. Alginate‐degrading bacteria were more abundant in the cold season relative to the summer season (10⁷ vs. 10⁴ CFU g^?1, respectively). Strong positive correlation was also observed between the number of alginate‐degrading bacteria and feed intake (R = 0.854; P < 0.01). The identified alginate‐degrading bacteria comprised of 35 species grouped into 11 genera including Algibacter, Formosa, Polarybacter, Tamlana, Tenacibaculum (CFB group), Roseobacter, Ruegeria, Silicibacter (α‐proteobacteria), Agarivorans, Shewanella and Vibrio (γ‐proteobacteria) respectively. More than 80% of the isolated alginate‐degrading bacteria belonged to the genus Vibrio, showing high homology to Vibrio cyclotorophicus, Vibrio splendidus, Vibrio halioticoli and Vibrio neonatus. Based on the results, it was suggested that algal‐polysaccharide (alginate) degrading bacteria (mainly Vibrio) commonly exist in the gut of abalone and may play an important role in the degradation and digestion of the host's feed.  相似文献   

Assessment of biomass recovery and soil carbon storage of fallow forests after swidden cultivation in the Bago Mountains,Myanmar     

Nyein Chan  Shinya Takeda  Reiji Suzuki  Sota Yamamoto 《New Forests》2016,47(4):565-585

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Stage-specific distribution of Japanese sea cucumber <Emphasis Type="Italic">Apostichopus japonicus</Emphasis> in Maizuru Bay,Sea of Japan,in relation to environmental factors     

Kenji Minami  Hideki Sawada  Reiji Masuda  Kohji Takahashi  Hokuto Shirakawa  Yoh Yamashita 《Fisheries Science》2018,84(2):251-259

The Japanese sea cucumber Apostichopus japonicus plays important ecological and economic roles in the coastal areas of Japan. Here, we aim to reveal the relation between habitat characteristics and density of juvenile and adult sea cucumbers in Maizuru Bay. Density of adult sea cucumbers was estimated by underwater visual surveys and bottom trawls and that of newly settled individuals by seedling collectors distributed in the bay. The physical environment of the sea bottom was evaluated from median diameter, total organic carbon, total nitrogen, carbon-to-nitrogen ratio, carbon isotope ratio, nitrogen isotope ratio, depth, slope, and distance from the coastline. Adult sea cucumber density was higher in the east side than the west side of Maizuru Bay, the former having a no-take zone for sea cucumbers. Juvenile sea cucumbers were most abundantly collected in the central part of the bay. High organic matter from the sea, short distance from the coastline, and high seabed gradient (steepness) had a positive effect on the density of adult sea cucumbers, and depth had positive effects on their body size. We suggest that sustainable management of sea cucumbers can be achieved by a combination of the establishment of no-take zones and increased protection of nursery habitats.  相似文献   

Characterization of the suppressive effects of the biological control strain VAR03-1 of <Emphasis Type="Italic">Rhizobium vitis</Emphasis> on the virulence of tumorigenic <Emphasis Type="Italic">R. vitis</Emphasis>     

Kirara Saito  Megumi Watanabe  Hidenori Matsui  Mikihiro Yamamoto  Yuki Ichinose  Kazuhiro Toyoda  Akira Kawaguchi  Yoshiteru Noutoshi 《Journal of General Plant Pathology》2018,84(1):58-64

Rhizobium vitis: strain VAR03-1 is a biological control agent that suppresses grapevine crown gall disease caused by a tumorigenic strain of R. vitis (Ti). Both acetosyringone-induced expression of a virulence gene and the growth of Ti were suppressed in vitro when it was cultivated in the VAR03-1 culture filtrate. These inhibitory effects were reduced by high-temperature treatment or incubation for 72 h. Both activities were detected in the high molecular weight fraction (>?100 kDa) of the filtrate. Our results suggest that the antagonistic effects of VAR03-1 on Ti are mediated by large particle(s) released in the culture media.  相似文献   

Changes in leaf water use after removal of leaf lower surface hairs on <Emphasis Type="Italic">Mallotus macrostachyus</Emphasis> (Euphorbiaceae) in a tropical secondary forest in Malaysia     

Tanaka Kenzo  Reiji Yoneda  Mohamad Alias Azani  Nik Muhamad Majid 《Journal of Forest Research》2008,13(2):137-142

Leaf hairs may assist in maintaining high leaf water use efficiency in tropical secondary forest tree species. We compared leaf temperature, transpiration, photosynthesis and water use efficiency between hairy and depilated leaves in Mallotus macrostachyus (Euphorbiaceae), to determine the role of leaf hair in leaf water use efficiency (WUE) in tropical degraded secondary forest in Malaysia. Measurements were made on five mature individuals growing in sun-exposed conditions and five in shaded conditions. The hair dry weight per unit leaf area was significantly greater in sun leaves than in shade leaves. The transpiration rate (Tr_max) of depilated leaves in sun-exposed conditions was slightly higher than in hairy leaves in both morning and afternoon measurements. In contrast, Tr_max in the shade leaves was almost identical in hairy and depilated leaves. Leaf stomatal conductance (g _s) in the morning showed almost the same value among leaf types and light conditions. In the afternoon, g _s slightly decreased from the morning values in both sun and shade conditions. In the morning, the leaf water use efficiency (A _max/Tr_max) in both conditions did not differ significantly between hairy and depilated leaves. However, in the afternoon, WUE in the depilated leaves was significantly lower than in hairy leaves in sun-exposed conditions. These observations suggest that leaf hairs in M. macrostachyus contribute to the high leaf water use efficiency in drought conditions, such as high vapor pressure deficit experienced at midday in degraded tropical secondary forests.  相似文献