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ISHIMARU Megumi

    Department of Science and Technology on Food Safety　Professor/Senior Staff
Last Updated :2024/04/25

Researcher Information

Degree

  • (BLANK)

J-Global ID

Research Interests

  • 細胞壁   細胞壁分解酵素   構造解析   ベレゾーン   基質特異性   組換えタンパク   園芸利用   果実軟化   ブドウ   軟化   ストレス反応   園芸利用学   貯蔵技術   品質保持   

Research Areas

  • Environmental science/Agricultural science / Horticulture

Academic & Professional Experience

  • 2020/04 - Today  Kindai UniversityFaculty of Biology-Oriented Science and Technology Department of Science and Technology on Food Safety教授

Education

  •        - 1999  Osaka Prefecture University  農学研究科  園芸農学

Association Memberships

  • THE JAPANESE SOCIETY OF APPLIED GLYCOSCIENCE   日本食品保蔵科学会   日本植物生理学会   園芸学会   

Published Papers

  • Kaori Matsuyama; Tatsuya Kondo; Kiyohiko Igarashi; Tatsuji Sakamoto; Megumi Ishimaru
    Planta Springer Science and Business Media LLC 252 (4) 72 - 72 0032-0935 2020/10 [Refereed]
     
    MAIN CONCLUSION: TBG4 recognize multiple linkage types substrates due to having a spatially wide subsite + 1. This feature allows the degradation of AGI, AGII, and AGP leading to the fruit ripening. β-galactosidase (EC 3. 2. 1. 23) catalyzes the hydrolysis of β-galactan and release of D-galactose. Tomato has at least 17 β-galactosidases (TBGs), of which, TBG 4 is responsible for fruit ripening. TBG4 hydrolyzes not only β-1,4-bound galactans, but also β-1,3- and β-1,6-galactans. In this study, we compared each enzyme-substrate complex using X-ray crystallography, ensemble refinement, and docking simulation to understand the broad substrate-specificity of TBG4. In subsite - 1, most interactions were conserved across each linkage type of galactobioses; however, some differences were seen in subsite + 1, owing to the huge volume of catalytic pocket. In addition to this, docking simulation indicated TBG4 to possibly have more positive subsites to recognize and hydrolyze longer galactans. Taken together, our results indicated that during tomato fruit ripening, TBG4 plays an important role by degrading arabinogalactan I (AGI), arabinogalactan II (AGII), and the carbohydrate moiety of arabinogalactan protein (AGP).
  • Tatsuya Kondo; Yuichi Nishimura; Kaori Matsuyama; Megumi Ishimaru; Masami Nakazawa; Mitsuhiro Ueda; Tatsuji Sakamoto
    Applied Microbiology and Biotechnology Springer Science and Business Media LLC 104 (3) 1135 - 1148 0175-7598 2020/02 [Refereed]
     
    Three recombinant β-galactosidases (BGALs; PcBGAL35A, PcBGAL35B, and PcGALX35C) belonging to the glycoside hydrolase (GH) family 35 derived from Penicillium chrysogenum 31B were expressed using Pichia pastoris and characterized. PcBGAL35A showed a unique substrate specificity that has not been reported so far. Based on the results of enzymological tests and 1H-nuclear magnetic resonance, PcBGAL35A was found to hydrolyze β-1,4-galactosyl residues linked to L-rhamnose in rhamnogalacturonan-I (RG-I) of pectin, as well as p-nitrophenyl-β-D-galactopyranoside and β-D-galactosyl oligosaccharides. PcBGAL35B was determined to be a common BGAL through molecular phylogenetic tree and substrate specificity analysis. PcGALX35C was found to have similar catalytic capacities for the β-1,4-galactosyl oligomer and polymer. Furthermore, PcGALX35C hydrolyzed RG-I-linked β-1,4-galactosyl oligosaccharide side chains with a degree of polymerization of 2 or higher in pectin. The amino acid sequence similarity of PcBGAL35A was approximately 30% with most GH35 BGALs, whose enzymatic properties have been characterized. The amino acid sequence of PcBGAL35B was approximately 80% identical to those of BGALs from Penicillium sp. The amino acid sequence of PcGALX35C was classified into the same phylogenetic group as PcBGAL35A. Pfam analysis revealed that the three BGALs had five domains including a catalytic domain. Our findings suggest that PcBGAL35A and PcGALX35C are enzymes involved in the degradation of galactosylated RG-I in pectin. The enzymes characterized in this study may be applied for products that require pectin processing and for the structural analysis of pectin.
  • Effects of hot-air treatment on the quality of blueberry fruits during storage
    松山佳織; 伴 琢也; 石丸 恵
    日本食品保蔵科学会誌 45 (4) 169 - 174 2019/07 [Refereed]
  • Fraidoon Karimi; Takashi Baba; Satoshi Noma; Daiki Mizuta; Jin Gook Kim; Manabu Watanabe; Megumi Ishimaru; Takuya Ban
    The Horticulture Journal Japanese Society for Horticultural Science 88 (3) 315 - 319 2189-0102 2019 [Refereed]
  • Masahiro Eda; Takashi Matsumoto; Megumi Ishimaru; Toshiji Tada
    PLANT JOURNAL WILEY-BLACKWELL 86 (4) 300 - 307 0960-7412 2016/05 [Refereed]
     
    Plant -galactosidases hydrolyze cell wall -(1,4)-galactans to play important roles in cell wall expansion and degradation, and turnover of signaling molecules, during ripening. Tomato -galactosidase4 (TBG4) is an enzyme responsible for fruit softening through the degradation of -(1,4)-galactan in the pericarp cell wall. TBG4 is the only enzyme among TBGs1-7 that belongs to the -galactosidase/exo--(1,4)-galactanase subfamily. The enzyme can hydrolyze a wide range of plant-derived (1,4)- or 4-linked polysaccharides, and shows a strong ability to attack -(1,4)-galactan. To gain structural insight into its substrate specificity, we determined crystal structures of TBG4 and its complex with -d-galactose. TBG4 comprises a catalytic TIM barrel domain followed by three -sandwich domains. Three aromatic residues in the catalytic site that are thought to be important for substrate specificity are conserved in GH35 -galactosidases derived from bacteria, fungi and animals; however, the crystal structures of TBG4 revealed that the enzyme has a valine residue (V548) replacing one of the conserved aromatic residues. The V548W mutant of TBG4 showed a roughly sixfold increase in activity towards -(1,6)-galactobiose, and similar to 0.6-fold activity towards -(1,4)-galactobiose, compared with wild-type TBG4. Amino acid residues corresponding to V548 of TBG4 thus appear to determine the substrate specificities of plant -galactosidases towards -1,4 and -1,6 linkages. Significance Statement Tomato -galactosidases (TBG1-TBG7) in the glycosyl hydrolase 35 (GH35) family are thought to play important roles during fruit development and maturation. Here we report the crystal structure of TBG4 in complex with its substrate.
  • Masahiro Eda; Megumi Ishimaru; Toshiji Tada
    ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS INT UNION CRYSTALLOGRAPHY 71 (Pt 2) 153 - 156 2053-230X 2015/02 [Refereed]
     
    Plant beta-galactosidases play important roles in carbohydrate-reserve mobilization, cell-wall expansion and degradation, and turnover of signalling molecules during ripening. Tomato beta-galactosidase 4 (TBG4) not only has beta-galactosidase activity but also has exo-beta-(1,4)-galactanase activity, and prefers beta-(1,4)-galactans longer than pentamers as its substrates; most other beta-galactosidases only have the former activity. Recombinant TBG4 protein expressed in the yeast Pichia pastoris was crystallized by the sitting-drop vapour-diffusion method using PEG 10 000 as a precipitant. The crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-parameters a = 92.82, b = 96.30, c = 159.26 angstrom, and diffracted to 1.65 angstrom resolution. Calculation of the Matthews coefficient suggested the presence of two monomers per asymmetric unit (V-M = 2.2 angstrom(3) Da(-1)), with a solvent content of 45%.
  • H. Izumi; Y. Murakami; M. Ishimaru; Y. Ozaki
    XI INTERNATIONAL CONTROLLED AND MODIFIED ATMOSPHERE RESEARCH CONFERENCE INT SOC HORTICULTURAL SCIENCE 1071 203 - 209 0567-7572 2015 [Refereed]
     
    Freshly peeled "baby persimmons", 3-4 cm in diameter and 20-25 g in weight, were prepared by enzymatic peeling of 'Totsutanenashi' cherry persimmon fruit (Diospyros kaki Thunb.), which is a bud mutation and miniature of the full size 'Hiratanenashi' persimmon. The microbiological and visual quality of enzymatically peeled baby persimmons as a fresh-cut fruit was evaluated during storage in air or high CO2 atmospheres (10, 15 and 20%) at 10 degrees C. The flesh of intact baby persimmon fruit showed counts of 2.6 log CFU/g for mesophilic aerobic bacteria and a non-detectable level for coliform groups and fungi. A hot water dipping treatment in the enzymatic peeling process reduced both the counts of mesophiles to levels below the lower limit of detection (2.4 log CFU/g) and the diversity of bacterial flora. Coliforms and fungi remained undetectable throughout the enzymatic peeling process. During storage in air, counts of mesophiles, coliforms, lactic acid bacteria, and fungi of baby persimmons increased to 4-5.5 log CFU/g by day 6, while high CO2 atmospheres reduced the microbial growth, with the greatest reduction observed in 15 or 20% CO2. Diversity of the microflora also decreased in 20% CO2 atmosphere as compared to air on day 6. High CO2 atmospheres inhibited the development of brown discoloration in baby persimmons by day 4, but all samples developed browning to an unmarketable level by day 6. These results indicate that high CO2 atmospheres of 15 to 20% are desirable for enzyme-peeled baby persimmons to extend the shelf life when stored at 10 degrees C.
  • Masahiro Eda; Megumi Ishimaru; Toshiji Tada; Tatsuji Sakamoto; Toshihisa Kotake; Yoichi Tsumuraya; Andrew J. Mort; Kenneth C. Gross
    JOURNAL OF PLANT PHYSIOLOGY ELSEVIER GMBH, URBAN & FISCHER VERLAG 171 (16) 1454 - 1460 0176-1617 2014/10 [Refereed]
     
    The open reading frame of tomato beta-galactosidase 1 was expressed in yeast, and the enzymatic properties and substrate specificity were investigated. The enzyme had peak activity at pH 5.0 and 40-50 degrees C. TBG1 was active on beta-(1,3)- and beta-(1,6)-galactobiose and lactose. TBG1 released galactose from lupin galactan, tomato fruit alkali soluble pectin, arabinogalactan, gum arabic and methyl beta-(1,6)-galactohexaoside, but not from labeled beta-(1,4)-galactoheptaose. TBG1 was assessed for its ability to degrade three galactosyl-containing cell wall fractions purified from different development and ripening stages of tomato fruit. TBG1 released galactose from all of the fractions from all of the stages tested. TBG1 activity was highest on the hemicellulose fraction at the 10 and 20 d after pollination stage. This result is not correlated the with TBG1 expression pattern. TBG1 might act on a small but specific set of polysaccharide containing galactose. (C) 2014 Elsevier GmbH. All rights reserved.
  • Tatsuji Sakamoto; Megumi Ishimaru
    APPLIED MICROBIOLOGY AND BIOTECHNOLOGY SPRINGER 97 (12) 5201 - 5213 0175-7598 2013/06 [Refereed]
     
    Arabinogalactans (AGs) are branched galactans to which arabinose residues are bound as side chains and are widely distributed in plant cell walls. They can be grouped into two types based on the structures of their backbones. Type I AGs have beta-1,4-galactan backbones and are often covalently linked to the rhamnogalacturonan-I region of pectins. Type II AGs have beta-1,3-galactan backbones and are often covalently linked to proteins. The main enzymes involved in the degradation of AGs are endo-beta-galactanases, exo-beta-galactanases, and beta-galactosidases, although other enzymes such as alpha-l-arabinofuranosidases, beta-l-arabinopyranosidases, and beta-d-glucuronidases are required to remove the side chains for efficient degradation of the polysaccharides. Galactanolytic enzymes have a wide variety of potential uses, including the bioconversion of AGs to fermentable sugars for production of commodity chemicals like ethanol, biobleaching of cellulose pulp, modulation of pectin properties, improving animal feed, and determining the chemical structure of AGs. This review summarizes our current knowledge about the biochemical properties and potential applications of AG-degrading enzymes.
  • Tatsuji Sakamoto; Hiromasa Tanaka; Yuichi Nishimura; Megumi Ishimaru; Naoya Kasai
    APPLIED MICROBIOLOGY AND BIOTECHNOLOGY SPRINGER 90 (5) 1701 - 1710 0175-7598 2011/06 [Refereed]
     
    A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 A degrees C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 A degrees C, respectively. Galactose was released from beta-1,3-d-galactan and beta-1,3-d-galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-beta-1,3-d-galactanase. Analysis of the reaction products of beta-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of beta-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, beta-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be beta-1,6-galactotriose and beta-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.
  • Tatsuji Sakamoto; Hiromasa Tanaka; Yuichi Nishimura; Megumi Ishimaru; Naoya Kasai
    APPLIED MICROBIOLOGY AND BIOTECHNOLOGY SPRINGER 90 (5) 1701 - 1710 0175-7598 2011/06 [Refereed]
     
    A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 A degrees C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 A degrees C, respectively. Galactose was released from beta-1,3-d-galactan and beta-1,3-d-galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-beta-1,3-d-galactanase. Analysis of the reaction products of beta-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of beta-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, beta-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be beta-1,6-galactotriose and beta-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.
  • Changes in inner contents of ‘Kyoho’ grape berry during the growth and ripening period.
    T. Ban; A. Nakatsuka; K. Akaura; S. Matsumoto; M. Ishimaru; H. Itamura
    Applied Horticulture 12 93 - 96 2010/12 [Refereed]
  • Megumi Ishimaru; David L. Smith; Andrew J. Mort; Kenneth C. Gross
    PLANTA SPRINGER 229 (2) 447 - 456 0032-0935 2009/01 [Refereed]
     
    The open reading frames of tomato beta-galactosidase (TBG) 4 and 5 cDNAs were expressed in yeast, and the enzymes properties and substrate specificities were investigated. The two enzymes had peak activities between pH 4-4.5 and 37-45A degrees C. TBG4 specifically hydrolyzed beta-(1 -> 4) and 4-linked galactooligosaccharides. TBG5 had a strong preference to hydrolyze beta-(1 -> 3) and beta-(1 -> 6)-linked galactooligosaccharides. Exo-beta-galactanase activity of the TBG enzymes was measured by determining the release of galactosyl residues from native tomato cell wall fractions throughout fruit development and ripening. Both TBGs released galactose from all of the fractions and stages tested. TBG4 activity was highest using chelator soluble pectin and alkali soluble pectin at the turning stage of ripening. Using aminopyrene trisulfonate labeled substrates, TBG4 was the only enzyme with strong exo-beta-(1 -> 4)-galactanase activity on 5 mer or greater galactans. TBG4 and TBG5 were both able to degrade galactosylated rhamnogalacturonan. Neither enzyme was able to degrade galactosylated xyloglucan.
  • Yoshiko Koshita; Shozo Kobayashi; Megumi Ishimaru; Yoshio Funamoto; Mikio Shiraishi; Akifumi Azuma; Hiroshi Yakushiji; Masayoshi Nakayama
    JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE JAPAN SOC HORTICULTURAL SCI 77 (1) 33 - 37 1882-3351 2008/01 
    A cDNA, VlmybA1-2, for an anthocyanin regulatory gene of grape was constructed under the control of the cauliflower mosaic virus (CaMV) 35SRNA promoter and introduced into leaf disks and petioles of kiwifruit (Actinidia deliciosa) plants by Agrobacterium-mediated gene transfer. When the tissues were cultured on selection medium, red cells visible to the naked eye formed at the cut ends of the segments after approximately 2 weeks. The cells developed into calluses, adventitious buds, and reddish-purple plantlets after 2, 3, and 6 months of culture, respectively. The pigment produced in the leaves of the transformed plants was determined to be cyanidin 3-O-(2-O-beta-xylosyl)-beta-glucoside (cyanidin 3-O-sambubioside). As VlmybA1-2 can also produce red cells in tomato and eggplant, it may be useful as a visible marker to confirm efficient transformation in dicots.
  • Megumi Ishimaru; David L. Smith; Kenneth C. Gross; Shozo Kobayashi
    JOURNAL OF PLANT PHYSIOLOGY ELSEVIER GMBH, URBAN & FISCHER VERLAG 164 (12) 1675 - 1682 0176-1617 2007/12 [Refereed]
     
    Expansins are cell-wall-localized proteins that induce Loosening of isolated plant cell walls in vitro in a pH-dependent manner, but exhibit no detectable hydrolase or transglycosylase activity. Three putative expansin cDNAs, Vlexp1, Vlexp2, and Vlexp3 were isolated from a cDNA library made from mature berries of the Kyoho grape. Expression profiles of the 3 genes were analyzed throughout berry development. Accumulation of the Vlexp3 transcript was closely correlated with berry softening, and expression of this gene was detected before veraison and markedly increased at veraison (onset of berry softening). Expression of Vlexp3 was berry-specific. Vlexp1 and Vlexp2 mRNA accumulation began during the expansion stage of berry development and expression increased for both genes during ripening. Vlexp1 and Vlexp2 mRNA was detected in Leaf, tendril and flower tissues and Vlexp2 mRNA was additionally detected in root and seed tissues. These findings suggest that the three expansin genes are associated with cell division or expansion and berry ripening. Vlexp3, in particular, is most likely to play a rote in grape berry softening at veraison. (C) 2006 Elsevier GmbH. All rights reserved.
  • Yoshihiro Imahori; Yoshitaka Suzuki; Minako Kawagishi; Megumi Ishimaru; Yoshinori Ueda; Kazuo Chachin
    POSTHARVEST BIOLOGY AND TECHNOLOGY ELSEVIER SCIENCE BV 46 (2) 160 - 166 0925-5214 2007/11 
    Harvested leaves of Chinese chives were stored in air + 10, 20 or 30% CO2, or air for 7 days at 20 degrees C to determine the effects of CO(2-)enriched atmospheres on their physiology and quality. Leaf yellowing was visible at day 5 in air, whereas CO, enrichment delayed yellowing and retarded chlorophyll and protein degradation that accompanied leaf senescence. At 30% CO2, undesirable off-odors were induced, presumably due to accumulation of ethanol in the tissue. The ethanol contents did not change during storage in leaves exposed to 10 or 20% CO2, or air, while the content in leaves exposed to 30% CO2 significantly increased. However, CO2 enrichment did not significantly influence acetaldehyde concentrations for the leaves. Alcohol dehydrogenase (ADH) activity increased in leaves exposed to 10 or 20% CO2, while its activity in leaves exposed to 30% CO2, was slightly higher than that of the control. Succinate dehydrogenase (SDH) activity greatly decreased in leaves exposed to 30% CO2, while its activity in leaves exposed to 10 or 20% CO2 only decreased slightly. The content of pyruvate increased in leaves exposed to 30% CO2, while its concentration in leaves exposed to 10 or 20% CO2, was slightly higher than that of the controls. Thus, our results indicate that it would be necessary to keep Chinese chives at 20 degrees C because of a lack of refrigeration in the distribution system, or in a modified atmosphere package designed to develop an optimum atmosphere during retail display, and suggest a potential for using CO2-enriched atmospheres at higher temperatures to help maintain quality. (C) 2007 Elsevier B.V. All rights reserved.
  • Yoshihiro Imahori; Izumi Kishioka; Kazuko Uemura; Eiichi Makita; Hitomi Fujiwara; Yuka Nishiyama; Megumi Ishimaru; Yoshinori Ueda; Kazuo Chachin
    JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE JAPAN SOC HORTICULTURAL SCI 76 (3) 258 - 265 1882-3351 2007/07 
    Sweetpotato roots were stored under a continuous flow of 0% or 1% O-2 (balance N-2) or air for 7 days at 20 degrees C to study the effects of short-term exposure to low OZ on their physiological responses and quality. During the course of the experiment, no visible signs of injury or decay were observed. However, low OZ treatments increased the soluble solid content and weak off-odors were detected by olfactory evaluation in roots stored at 0%O-2. The intensity of off-odors increased as the concentrations of acetaldehyde and ethanol increased in roots during storage. Ethanol concentrations were higher than those of acetaldehyde, which remained low during storage in 1% O-2 and air, but increased greatly in roots stored at 0% O-2. Pyruvate decarboxylase (PDC) activities in roots exposed to 0% or 1% OZ increased by 3.1- and 2-fold respectively over levels in roots stored in air by day 7. Alcohol dehydrogenase (ADH) activities in roots exposed to 0% or 1% OZ increased by 1.6- and 1.7-fold respectively over levels in roots stored in air by day 7. ADH-specific activity was about 10-times that of PDC. The pH of root homogenate exposed to air remained constant, whereas the pH increased and decreased, respectively, in roots stored at 0% or 1 % O-2. PDC showed stability over the pH range 5.5-7.0, whereas ADH exhibited stability over the pH range 6.0-7.5. The Km of PDC in sweetpotato was 0.56 mM for pyruvate, whereas the Km of ADH was 0.19 mM for acetaldehyde. From these results, there may be some potential for the short-term exposure of sweetpotato roots to low 02 in place of low temperature treatment to prolong shelf-life, although ethanol fermentation may be accelerated under low OZ atmospheres.
  • ISHIMARU Megumi
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 33 (2) 77 - 83 1344-1213 2007/03 
    高等植物の形と大きさをもっとも直接的に決めているのは細胞壁である。細胞膜の外側に位置し植物細胞の最外層を構成する細胞壁はかつて後形質と呼ばれ、死んだ成分として扱われてきた。しかし、現在では細胞壁が、多くの酵素が活動する活発な代謝の場であることが明らかになってきた。細胞壁はその性質を絶え間なくダイナミックに変化させ、形態形成や生長調節ばかりでなく、ほかの生命活動の調節においても重要な役割を果たしていることが明らかになってきた。細胞壁を構成するさまざまな成分は、ほかの細胞成分と同様に遺伝情報に基づいて合成・分解されている。しかし、高等植物の場合、遺伝的プログラムは周囲の環境によって強く修飾されやすい。これは進化上、固着生活を選択した植物にとって宿命ともいえる特徴であり、植物は動物以上に敏感で精密な環境応答機構を備えている。ここでは、果実特にブドウ果実とトマト果実の細胞壁分解関連酵素の遺伝子およびタンパクに注目し、細胞壁の構造と代謝やそれらに対する酵素タンパクの作用に的を絞り言及していきたい。
  • Sumithra K. Wendakoon; Yoshinori Ueda; Yoshihiro Imahori; Megumi Ishimaru
    Journal of the Science of Food and Agriculture 86 (13) 2241  0022-5142 2006/10 [Refereed]
  • Sumithra K. Wendakoon; Yoshinori Ueda; Yoshihiro Imahori; Megumi Ishimaru
    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE JOHN WILEY & SONS LTD 86 (10) 1475 - 1480 0022-5142 2006/08 
    Yellow, ripened (yellow with green tips) bananas were treated with nitrogen gas for 12, 24 and 48 h at 20 degrees C to study the effects of anaerobic conditions on the fruit quality, including the production of volatile compounds and activity of alcohol acetyltransferase (AAT) during the post-harvest period. Significantly higher concentrations of acetaldehyde and ethanol were found in the treated fruit than in the untreated bananas after removal from the conditions. The 48-h treatment showed higher levels of ethanol and acetaldehyde after storage. Immediately after releasing the fruit from the anaerobic atmosphere, the amounts of isobutyl acetate and isoamyl acetate decreased. The production of ethyl acetate increased markedly in each treatment unit 1 day after removing the fruit. Regardless of recovery from the production of isobutyl acetate and isoamyl acetate 1 day after treatment, the banana-like aroma was denatured because of the production of high levels of ethyl acetate and ethanol. The increase in AAT was slightly lower in nitrogen-treated fruit than untreated fruit. However, the activity in treated fruit was sufficient for ester production in bananas. The endogenous alcohol levels were increased during nitrogen gas treatment in the fruit due to the inhibition of ester production. Colour development of the bananas was greatly inhibited by the treatments, while the sugar content did not show any differences between the treated and untreated fruit. The results suggest that, even if bananas are removed from the short-term anaerobic conditions, a loss in quality, except sweetness, easily occurs afterwards, especially the characteristic aroma of the fruit during the post-harvest period. (c) 2006 Society of Chemical Industry.
  • V. Srilaong; Y. Tatsumi; M. Ishimaru
    PROCEEDINGS OF THE IVTH INTERNATIONAL CONFERENCE ON MANAGING QUALITY IN CHAINS, VOLS 1 AND 2 INT SOC HORTICULTURAL SCIENCE 712 (712) 661 - + 0567-7572 2006 
    Respiratory pattern and succinate dehydrogenase (SDH) activity in cucumber fruit stored in 5%, 21% (air control) and 100% O-2 at 5 degrees C were studied. Storage in 100% O-2 at 5 degrees C was most effective for suppressing the respiratory rate in cucumber fruit, the rate being lower than in fruit stored in either 5% O-2 or air. Relative activity of SDH in cucumber fruit stored in 100% O-2 was lower than in other storage conditions. Only slightly different SDH activity was recorded between control and 5% O-2-treated fruit. Northern hybridization with a partial cDNA of cucumber sdhB as a probe revealed a constant level of shdB gene expression during storage. These results suggesting that change of SDH is post-transcriptionally regulated.
  • Wendakoon S.K; Ueda Y; Imahori Y; Ishimaru M
    Journal of Japanese Association of Food Preservation Science Japan Association of Food Preservation Scientists 30 (1) 17 - 21 1344-1213 2004/10 [Refereed]
     
    For the determination of acetate ester formation, banana pulp slices or pulp cells suspension were incubated with pyruvate, acetate or citrate, alcohol, and co-factors. When the various concentrations of pyruvate were added to the pulp slices, higher concentrations showed more acetate ester production. Addition of ATP, CoA and Mg to the pulp cells also induced the formation of acetate esters. Substrates and co-factors accelerating TCA cycle enhanced the ester formation in the cell suspension. Results indicate that acid part of acetate esters was mainly derived from pyruvate via acetate in banana fruit although small amount of acetyl CoA was also formed from citrate.
  • M Ishimaru; K Kagoroku; K Chachin; Y Imahori; Y Ueda
    SCIENTIA HORTICULTURAE ELSEVIER SCIENCE BV 101 (1-2) 1 - 10 0304-4238 2004/05 [Refereed]
     
    Polyethylene film and corrugated cardboard were used to package and store burdock roots (Arctium lappa L.) at 2, 8, and 20degreesC in an attempt to maintain the good appearance of heat-processed burdock sticks. The weight loss was as high as 60% of fresh weight when corrugated cardboard cartons were used for storage at 20degreesC. However, polyethylene bag packaging or low temperature storage resulted in lower levels of weight loss (less than 30%). To control the formation of white solids in exudate from processed sticks, low temperatures (2 degreesC) and storage of burdock roots for more than 30 days before processing were used to maintain the good appearance of burdock sticks. There was a significant decline in sugar content during storage at 8 and 20 degreesC, corresponding to an increased production of white solids. The fructan composition of raw burdock roots decreased faster to about 60% after storage for 30 days at 2 degreesC than at other storage temperatures (to about 30%). Inulinase activity in burdock roots stored at 2 degreesC was higher than in those stored at 8 and 20 degreesC. The amount of muddy exudate and the sugar content in solutions surrounding burdock sticks were related to the storage temperature before processing. These results indicate that the storage of burdock roots in polyethylene film packaging for 30 days at 2 degreesC is suitable to prevent the formation of muddy precipitate in processed burdock sticks. (C) 2003 Elsevier B.V. All tights reserved.
  • SK Wendakoon; Y Ueda; Y Imahori; M Ishimaru
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AMER CHEMICAL SOC 52 (6) 1615 - 1620 0021-8561 2004/03 [Refereed]
     
    The effect of anaerobic conditions on acetate ester biosynthesis in ripened banana pulp was investigated. Incubation of the pulp in less than 1% O(2) resulted in a significant reduction in the formation of ethyl acetate. Regardless of the presence of a large amount of endogenous ethanol and the remaining exogenous isobutyl alcohol after complete anaerobic incubation with the pulp, the production of acetate ester decreased. The effect of addition of pyruvate, isobutyl alcohol, acetate, and methyl hexanoate on acetate ester formation in 100% N(2) was also investigated. The addition of pyruvate and isobutyl alcohol to the pulp gave lower acetate esters in N(2) than in air, whereas the pulp incubated with acetate and isobutyl alcohol produced more acetate ester in both conditions. Therefore, the lack of acetyl CoA, or more precisely acetate, in the tissue is the main reason for the inhibition of acetate ester formation under anaerobic conditions. The activity of beta-oxidation measured by incubation with methyl hexanoate was detected only in the samples incubated in air. The formation of acetyl CoA, derived from pyruvate through mitochondria and through beta-oxidation, was inhibited by anaerobic conditions, which suggests that mitochondrial activity and/or beta-oxidation are essential for ester biosynthesis.
  • 石丸 恵
    農業および園芸 養賢堂 78 (12) 1281 - 1287 0369-5247 2003/12 [Invited]
  • Khanom M; Ueda Y; Imahori Y; Ishimaru M; Noichinda S
    Applied Biological Science 大阪府立大学生物資源開発センタ- 7 (2) 71 - 83 1341-5573 2003/04 [Refereed]
  • ISHIMARU Megumi; CHACHIN Kazuo; UEDA Yoshinori
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 29 (6) 323 - 327 1344-1213 2003/03 [Refereed]
     
    β-D-galactosidase was partially purified to homogeneity from persimmon (Diospyros kaki Thunb. cv. Tonewase) fruit. The enzyme of G-II fraction was purified 38. 1-fold with a total yield of 14.6%. The molecular weight of native β-D-galactosidase was estimated to be about 120kDa by ND-PAGE. After SDS-PAGE of the enzyme electroeluted from native gels, two subunits with estimated molecular masses of 35kDa and 46kDa were observed. The optimum pH of the enzyme activity was found to be pH5.0, and the enzyme stable in the range of pH 5-8.
  • BAN Takuya; ISHIMARU Megumi; OSE Kimiko; YAMAGUCHI Masaatsu; UEDA Hisafumi
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 29 (3) 153 - 157 1344-1213 2003/02 [Refereed]
     
    There has been an increasing amount of attention to the health benefits of consuming blueberries (lowbush blueberry, highbush blueberry and rabbiteye blueberry) recently. Hence, blueberries contain anthocyanins, and the anti-oxidant activity of anthocyanins was reported in recent research. Blueberry fruit often have been consumed in jam, however the changes in anthocyanin pigments during jam process are still unclear. Using 10 cultivars and 3 selections of blueberries, we investigated the changes in anthocyanin composition during jam manufacturing. In fresh fruit, 8 to 14 anthocyanins were found, and the anthocyanin compositions were differing from each cultivar (selection). The anthocyanin compositions of the blueberry jams were almost same with that of the fresh fruit. From these results, it is concluded that the anthocyanin composition in blueberry fruit do not change during jam manufacturing.
  • Relationship between volatiles and other factors indicating quality of melon (Cucumis melo cv. Prince Melon) during fruit development and storage.
    Khanom M; Ueda Y; Ishimaru M
    Scientific Report of Graduate School of Agriculture & Biological Sciences, Osaka Prefecture University 55 7 - 14 2003/01 [Refereed]
  • ISHIMARU Megumi; CHACHIN Kazuo; UEDA Yoshinori
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 29 (2) 89 - 93 1344-1213 2003/01 [Refereed]
     
    Tonewase'fruit is the most popular Japanese persimmon (Diospyros kaki Thunb.) in Japan. It has fine flesh and good taste after its astringency was removed. But the fruit has very short shelf life, because of rapid softening. There are two ways for removing astringency; 1) treatment with alcohol on tree and 2) treatment with carbon dioxide (CO2). The present study was conducted to investigate the relationship between the changes in fruit firmness and β-D-galactosidase activity which was hydrolyzed hemicellulosic components. (1) The loosing of fruit firmness was not different between treatments of alcohol on tree and CO2 at 20°C for 24 hours (CTSD method) for removing astringency until 4 days after storage at 20°C, however, the former showed slow softening during storage for 8 days but the latter was rapid softening at 6 days (5 days after treatment). The respiration and ethylene production of fruits treated with carbon dioxide and non-treatment were similar pattern and increased at the end of storage period. However, the fruit of alcohol treatment on tree maintained low level which was comparison with non-treatment and carbon dioxide fruit. (2) The activity of β-D-galactosidase which was non-treatment and CTSD treatment for removal astringency increased during storage. The fruit of alcohol treatment on tree maintained low activity during storage. Finally, the activity of non-treatment and CTSD treatment fruit was higher than alcohol treatment on tree one during storage. These results indicated that the fruit softening of 'Tonewase' is attributable to increase of ethylene production and attended to increased, β-D-galactosidase activity. It was suggested that the fruit softening of alcohol treatment on tree, CTSD treatment, and non-treatment fruits were depend on a degree of hydrolyzed hemicellulosic components during storage or postharvest.
  • Y. Imahori; K. Matushita; M. Kota; Y. Ueda; M. Ishimaru; K. Chachin
    Journal of Horticultural Science and Biotechnology Headley Brothers Ltd 78 (3) 386 - 393 1462-0316 2003 [Refereed]
     
    Tomato fruit was stored under a continuous flow of 0% and 3% O2 (balance N2) or air for 7 d at 20°C to study the regulation of fermentative metabolism. The concentrations of ethanol and acetaldehyde were very low during storage at 3% O2 and air. At 0% O2, ethanol and to a lesser extent acetaldehyde, rapidly accumulated in the tissue. However, lactate concentration did not change during the experiment and was not significantly influenced by O2 concentration. Pyruvate decarboxylase (PDC) activity greatly increased in fruit exposed to 3% O2, while activity in fruit exposed to 0% O2 was the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 3%, but at 0% O2 was the same level as the control. Lactate dehydrogenase (LDH) activity greatly increased in fruit exposed to 3%, but at 0% O2 was the same level as the control. The ADH activity in tomato fruit was about ten times greater than that of PDC activity and about 100 times greater than that of LDH activity during storage. Concentration of NADH in fruit exposed to 3% O2 was greater than that in fruit exposed to 0% O2 and air. Concentrations of pyruvate did not change during storage at 1% O2 and air. At 0% O2, pyruvate rapidly accumulated in its tissue. The Km of ADH in tomato fruit was 0.28 mM for acetaldehyde, and 0.058 mM for NADH. The Km of PDC in tomato fruit was 0.38 mM for pyruvate. The Km of LDH in tomato fruit was 0.18 mM for pyruvate. Possible regulation of fermentative metabolism is briefly considered.
  • T. Ban; M. Ishimaru; S. Kobayashi; S. Shiozaki; N. Goto-Yamamoto; S. Horiuchi
    Journal of Horticultural Science and Biotechnology Headley Brothers Ltd 78 (4) 586 - 589 1462-0316 2003 [Refereed]
     
    The effects of abscisic acid (ABA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on the expression of seven anthocyanin biosynthetic pathway genes in 'Kyoho' grape berries were investigated. In untreated berries, the expression of the UDP-glucose-flavonoid: 3-O-glucosyltransferase (UFGT) gene was detected only at 42 d after full bloom (DAB), whereas the phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR) and leucoanthocyanidin dioxygenase (LDOX) genes were expressed throughout the growing period. ABA increased anthocyanin content in the skin and the expression of PAL, CHS, CHI, DFR and UFGT genes at 7 d after treatment. In contrast, 2,4-D inhibited the accumulation of anthocyanin and the expression of all the genes examined. The results clearly show that the anthocyanin levels resulting from the application of ABA and 2,4-D were correlated with the expression of anthocyanin biosynthetic pathway genes.
  • S Kobayashi; M Ishimaru; K Hiraoka; C Honda
    PLANTA SPRINGER-VERLAG 215 (6) 924 - 933 0032-0935 2002/10 [Refereed]
     
    Partial cDNAs of myb-related regulatory genes were isolated from the tetraploid Kyoho grape (Vitis labruscana: V. labrusea x V. vinifera) and the expression patterns of the corresponding genes were studied. Since MybA gene expression is closely related to coloring and/or ripening of the berry (expression increases strongly with the commencement of coloring and berry softening, and is detected only in berry skin and flesh), full-length cDNAs for the gene were isolated from a mature-berry cDNA library. Three different species of MybA were identified from the cDNA sequences. Delivery of these cDNAs to somatic embryos of grape led to the induction of reddish-purple spots and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) gene expression in non-colored embryos. The UFGT transcript was not detected in control embryos, while other structural genes for anthocyanin biosynthesis were expressed in both control and pigmented embryos. In addition, introduction of the UFGT gene induced the same reddish-purple spots in embryos. In contrast, treatment with the leucoanthocyanidin dioxygenase (LDOX) gene failed to induce these spots. Our results strongly suggest that MybA genes are involved in the regulation of anthocyanin biosynthesis in the grape via expression of the UFGT gene.
  • ISHIMARU Megumi; CHACHIN Kazuo; WADA Yasunori; UEDA Yoshinori
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 28 (3) 119 - 125 1344-1213 2002/06 [Refereed]
     
    'Hiratanenashi' fruit is the most popular Japanese persimmon (Diospyros kaki Thunb.) in Japan.It has fine flesh and good taste after its astringency was removed. But the fruit has very short shelf life, because of rapid softening after removed astringency. 'Tuyu' fruit is also popular persimmon fruit which is the non-astringency cultivar. The present study was conducted to investigate the relationship between the changes in fruit firmness and cell wall composition (pectic and hemicellulosic composition) and 'Eliratanenashi' and 'Tuyu' cultivars. (1) Sugar of phenol-acetic acid-water (PAW) fraction from 'Tuyu' fruits were increased, but the content of 'Hiratanenashi' fruit did not change during storage. Soluble polyuronide contents increased both cultivars during storage. (2) The contents of cyclohexane-trans-1, 2-diamine tetra-acetate (CDTA) soluble polyuronide and sugar contents of 'Fuyu' fruit was decreased markedly during from 10 day to 15 day in storage. 'Hiratanenashi' fruit was not change during storage.The contents of Na2CO3 soluble polyuronide and sugar contents of both cultivars were similar pattern of CDTA soluble fraction. (3) The contents of guanidium-thiocyanate (GTC) -soluble and KOH-soluble sugar from hemicellulosic components did not change in 'Hiratanenashi' and 'Tuyu' fruit during storage. These results indicated that the fruit softening of 'Hiratanenashi' and 'Tuyu' are attributable to increase of water-soluble polyuronide and decrease of water-insoluble polyuronide contents. Pectic component in 'Fuyu' fruit is much quantity comparison with 'Hiratanenashi' fruit, and polyuronide and sugar contents in pectic component of both cultivars have a similar tendency to fruit firmness.
  • Yoshihiro Imahori; Mika Kota; Yoshinori Ueda; Megumi Ishimaru; Kazuo Cachin
    Postharvest Biology and Technology 25 (2) 159 - 167 0925-5214 2002 [Refereed]
     
    Bell pepper fruit were stored under a continuous flow of 0 and 1% O2 (balance N2) or air for 7 days at 20°C to study the regulation of ethanolic fermentation. The concentrations of ethanol and acetaldehyde were very low during storage at 1% O2 and air. At 0% O2, ethanol and to a lesser extent acetaldehyde, rapidly accumulated in the tissue. Pyruvate decarboxylase (PDC) activity greatly increased in fruit exposed to 1% O2, while activity in fruit exposed to 0% was only slightly higher than that of the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 1% but at 0% O2 was at the same level as the control. The activity of ADH was about 10 times that of PDC during storage. Changes in ADH isozymes correlated well with changes in ADH activity. Concentration of NADH did not change during storage in air, but in fruit in 0 and 1% O2 showed a significant increase. Concentrations of pyruvate were very low and did not change during storage at 1% O2 and air. At 0% O2, pyruvate rapidly accumulated in the tissue. The Km of ADH in bell pepper fruit was 0.74 mM for acetaldehyde, and 0.33 mM for NADH. The Km of PDC in bell pepper fruit was 0.92 mM for pyruvate. Possible regulation of ethanolic fermentation is briefly considered. © 2002 Elsevier Science B.V. All rights reserved.
  • Megumi Ishimaru; Shozo Kobayashi
    Plant Science 162 (4) 621 - 628 0168-9452 2002 [Refereed]
     
    Six partial cDNAs for cell wall degradation-related enzymes, xyloglucan endo-transglycosylase (XET), polygalacturonase (PG), pectin methylesterase (PME), pectate lyase (PL), cellulase (Cel), and β-D-galactosidase (GAL), were isolated from a véraison -specific subtractive library made from Kyoho grape (Vitis labruscana) berries. During the development of Kyoho grape berries, the expression of these genes was analyzed. Among the genes analyzed, XET gene expression was closely related to berry softening slight XET gene expression was detected before véraison and was markedly increased at véraison (the stage of the onset of berry softening). In addition, the expression of the gene was berry specific. In the other genes, except for PL, however, no expression was detected during the berry development PL was detected only after the coloring stage began. These observations suggest that XET plays an important role in grape berry softening. To obtain further information about this gene, a full-length cDNA clone (VXET 1) encoding XET was isolated from a cDNA library of Kyoho grape berries and characterized. The VXET 1 was 1326 bp in length and contained a 5′-untranslated region of 67 bp, an open reading frame of 873 bp, and a 3′-untranslated region of 386 bp. The deduced amino acid sequence of the VXET 1 showed 73.5% identity with the corresponding XET (NXG 1) from nasturtium (Tropaeolum majus) that has been shown to have endo-glucanase activity. These findings suggest that the VXET 1 product cleaves a cellulose-xyloglucan network of cell wall and induces the softening of Kyoho grape berries at véraison. © 2002 Elsevier Science Ireland Ltd. All rights reserved.
  • Y. Imahori; I. Kishioka; K. Uemura; H. Yoshioka; Y. Ueda; M. Ishimaru; K. Chachin
    Journal of Horticultural Science and Biotechnology Headley Brothers Ltd 77 (6) 677 - 682 1462-0316 2002 [Refereed]
     
    Japanese pear 'Kosui' fruits were stored under a continuous flow of 0%, 1%, 3%, 5% and 10% O2 (balance N2) or air for 7 d at 20°C to study the effects of low O2 on their physiological responses and quality attributes. Low O2 treatments did not significantly influence changes in skin colour and soluble solids content. However, weak off-flavours were detected in the fruits stored at 0% O2 on day 3, and the intensity of these off-flavours increased as storage progressed. The concentrations of acetaldehyde in fruit increased throughout the storage period. The ethanol concentration was greatly increased in fruits stored at 0% O2. Moreover, ethanol concentrations were much higher than those of acetaldehyde and remained very low during storage in air, but their concentration were just slightly increased in fruits exposed to 1%, 3%, 5% and 10% O2. Pyruvate decarboxylase activity was greatly increased in fruits exposed to 1% and 3% O2, while its activity in fruits exposed to 5% and 10% O2 were only slightly higher than that of the control and at 0% O2 at the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 0%, 1%, 3% and 5% O2, while at 10% O2, ADH was only slightly higher than the control. Changes in ADH isozymes correlated well with changes in ADH activity. The homogenate pH of fruits exposed to 1%, 3%, 5% and 10% O2 and air remained constant, while in fruit stored at 0% O2 their pH increased. The potential for using low O2 atmospheres to help in maintaining the quality of Japanese pear 'Kosui' is discussed.
  • ISHIMARU Megumi; CHACHIN Kazuo; WADA Yasunori; UEDA Yoshinori
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 27 (4) 197 - 204 1344-1213 2001/06 [Refereed]
     
    'Hiratanenashi' fruit is the most popular Japanese persimmon (Diospyros kaki Thunb.) in Japan. It has fine flesh and good taste after its astringency was removed. But the fruit has very short shelf life, because of rapid softening. There are two ways for removing astringency ; 1) treatment with alcohol and 2) treatment with carbon dioxide (CO2). The present study was conducted to investigate the relationship between the changes in fruit firmness and cell wall composition (pectic and hemicellulosic composition). (1) The rate of fruit softening was different between treatments of alcohol in 20°C for 5 days and CO2 in room temperature for 24 hours for removing astringency, the former was more rapid softening than the latter. The respiration and ethylene production of fruits treated with alcohol or carbon dioxide were temporarily increased after the treatment. (2) Sugar of phenol-acetic acid-water (PAW) fraction from fruits treated with alcohol or CO2 were increased, but the content of non-treated fruit did not change during storage. Soluble polyuronide contents increased in order of control < CO2 treatment < alcohol treatment. (3) The contents of guanidium-thiocyanate (GTC) -soluble and KOH-soluble sugar from hemicellulosic components did not change in non-treated fruit during storage and the sugar content of fruits treated with alcohol or CO2 decreased by half in 3 days after treatment. These results indicated that the fruit softening of 'Hiratanenashi' is attributable to increase of water-soluble polyuronide and decrease of water-insoluble polyuronide contents. It was suggested that the different rate of fruit softening between alcohol and CO2 treatments were depended on a degree of increase of water-soluble polyuronide and decrease of water-insoluble polyuronide. Breakdown of hemicellulosic component did not reflect the difference of the softening by both treatments.
  • S. Kobayashi; M. Ishimaru; C. K. Ding; H. Yakushiji; N. Goto
    Plant Science 160 (3) 543 - 550 0168-9452 2001/02 [Refereed]
     
    The expression of the UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) gene has been shown to be critical for anthocyanin biosynthesis in the grape berry. Using white cultivars and bud sports with red skin, we examined the expression of seven anthocyanin biosynthetic genes including the UFGT gene and compared the coding/promoter sequences of the UFGT gene. Northern blot analysis showed that the seven anthocyanin biosynthetic genes were expressed coordinately at higher levels in the red-skin sports than in the white-skin progenitors of the sports. It was especially notable that UFGT gene expression was detected only in the red-skin sports and Kyoho. However, there were no differences in either coding or promoter sequences between Italia (Vitis vinifera) and its red-skin sport Ruby Okuyama, or between Muscat of Alexandria (V. vinifera) and the red-skin sport Flame Muscat. From these findings, the phenotypic change from white to red in the sports is thought to be the result of a mutation in a regulatory gene controlling the expression of UFGT. © 2001 Elsevier Science Ireland Ltd.
  • Ishimaru Megumi; Yamamoto Takashi; Morioka Akira; Ueda Yoshinori; Chachin Kazuo
    Journal of the Japanese Society for Horticultural Science THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 68 (4) 890 - 896 0013-7626 1999/12 [Refereed]
     
    Immature and mature Japanese persimmon 'Tonewase' fruit were treated with 1) 100% CO_2 for 24 hr (control) or 2) 100% CO_2 for 17 hr and gradual reduction to 0% CO_2 for 7 hr (combination treatment) to remove their astringency ; a third group was left untreated. The levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and ACC synthase and ACC oxidase activities in their extracts were analyzed. The effects of adding catechin and bovine serum (BSA) separately to the extraction medium on the enzyme activities were also determined. 1. The ACC content in immature untreated and control fruit rapidly increased during storage at 20℃, whereas that in fruits exposed to the combination treatment remained low during storage. Mature treated fruits responded similarly to the immature treated ones. 2. The ACC synthase activity of immature fruit exposed to the combination treatment remained very low compared to the untreated and control fruit. The ACC synthase activity of immature fruit was significantly inhibited by the combination treatment compared to that of mature fruit. 3. The ACC oxidase activity in both immature and mature fruit was less inhibited by the combination treatment, compared to ACC synthase activity. 4. The ACC synthase activity was inhibited by the addition of catechin in the extraction medium but it was promoted by the addition of BSA. These results indicate that the inhibition of ethylene evolution by Japanese persimmon 'Tonewase' with 100% CO_2 for 24 hr or the combination treatment in which CO_2 is reduced to 0% may be attributed to the blockage of S-adenosylmethionine conversion to ACC.
  • Ishimaru Megumi; Yamamoto Takashi; Chachin Kazuo
    Journal of the Japanese Society for Horticultural Science THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 67 (5) 812 - 814 0013-7626 1998/10 [Refereed]
     
    Two experiments were conducted to test the effects of exposing Japanese persimmon 'Tonewase' fruit harvested at different maturies to varying concentrations of carbon dioxide on firmness, the evolution of ethylene and respiration. In Phase I, the fruits were exposed to ambient air and to 100% carbon dioxide for 24 hr (control) and subsequently stored at 20℃. In Exp. I, Phase I was repeated on immature fruit and the third treatment was added in which the carbon dioxide concentration was decreased from 100% to 0% after 17 hr. In Exp. II, the procedure was similar to that in Exp. I, except that more mature fruits were used and the carbon dioxide concentration was reduced from 100% to 0% after 6, 12 and 20 hr. 1. The fruits of the Japanese persimmon 'Tonewase' exposed to ambient air and those treated continuously with 100% carbon dioxide softened equally fast and ripened within 6 days. 2. Slightly immature fruits exposed to air and 100% carbon dioxide softened as in Phase I, whereas those exposed to 100% carbon dioxide for 17 hr were still firm after 2 weeks in storage. 3. Fruits exposed to air and 100% carbon dioxide softened as did those in Phase I, wheras those exposed to 100% carbon dioxide for 6, 12 and 20 hrs maintained their firmness longer during storage.
  • Effects of on-tree removal of astringency by ethanol treatment on β-D-galacosidase gene expression of Japanese persimmon Tonewase fruit.
    Ishimaru M; Kobayashi S; Imahori Y; Ueda Y
    Applied Biological Science 4 77 - 83 1998/10 [Refereed]
  • ISHIMARU Megumi; IMAHORI Yoshihiro; TATSUMI Yasuo; CHACHIN Kazuo
    journal of the japanese society for cold preservation of food Japan Association of Food Preservation Scientists 24 (4) 243 - 247 1344-1213 1998/06 [Refereed]
     
    Sterilizing effect on the dipping treatment of sodium hypochlorite solution has become more useful in the field of food processing. In this study, the sterilization effect of dipping treatment with sodium hypochlorite solution on the ascorbic acid contents of partially processed vegetables (lettuce and cabbage) were investigated. During the treatment of sodium hypochlorite solution, the ascorbic acid contents of fresh-cut lettuce and cabbage decreased and then a large portion of total ascorbic acid was converted to dehydroascorbic acid. The total ascorbic acid content was further decreased by wash in water process after the treatment of sodium hypochlorite solution.

Books etc

  • 山内, 直樹; 今堀, 義洋 (Contributor)文永堂出版 2021/04 9784830041426 xvi, 293p
  • 食品加工・保蔵学
    石丸 恵 (Contributor)2017/07
  • 地球変動研究の最前線を訪ねる
    小川利紘; 及川武久; 陽 捷行; 石丸 恵 (Joint work)清水弘文堂 2010/02

Conference Activities & Talks

  • モモ果実由来エクスパンシンの糖加水分解活性について  [Not invited]
    松山佳織; 近藤辰哉; 阪本龍司; 砂川直輝; 五十嵐圭日子; 石丸 恵
    第11回細胞壁研究者ネットワーク定例会  2017/10
  • モモ果実由来エクスパンシンの糖加水分解活性  [Not invited]
    松山佳織; 近藤辰哉; 阪本龍司; 砂川直輝; 五十嵐圭日子; 石丸 恵
    日本応用糖質科学会平成29年度大会  2017/09
  • 新規植物親和性材料およびその利用について（第一報）  [Not invited]
    石丸 恵; 古薗 勉; 神崎真哉; 伴 琢也
    園芸学会平成29年度秋季大会  2017/09
  • 青果物の収穫後の高温環境による生理化学変化とその利用  [Invited]
    石丸 恵
    日本食品保蔵科学会第66回大会  2017/06
  • ブドウ黒とう病に対する抵抗性機構の解明（第三報）  [Not invited]
    宮本綾子; 河野 淳; 今堀義洋; 石丸 恵
    園芸学会平成29年度春季大会  2017/03
  • モモ果実の軟化に関与するPpEXP1の糖加水分解活性の有無について  [Not invited]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    園芸学会平成29年度春季大会  2017/03
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異（V548W)導入による酵素特性および基質特異性の変化  [Not invited]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    第10回細胞壁ネットワーク定例会  2016/10
  • モモ果実の軟化に関与するPpEXP1の機能解析に向けた基礎的研究  [Not invited]
    松山佳織; 小野裕美; 今井友也; 石丸 恵
    園芸学会平成28年度秋季大会  2016/09
  • ブドウ黒とう病に対する抵抗性機構の解明（第二報）  [Not invited]
    宮本綾子; 河野 淳; 佐藤明彦; 今堀義洋; 石丸 恵
    園芸学会平成28年度春季大会  2016/03
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異（V548W)導入による酵素特性および基質特異性の変化  [Not invited]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    園芸学会平成28年度春季大会  2016/03
  • トマト果実の軟化に関与するβ-ガラクトシダーゼ１および５の機能解析  [Not invited]
    近藤辰哉; 松山佳織; 阪本龍司; 石丸 恵
    園芸学会平成28年度春季大会  2016/03
  • ブドウ黒とう病に対する抵抗性機構の解明  [Not invited]
    宮本綾子; 河野 淳; 佐藤明彦; 今堀義洋; 石丸 恵
    園芸学会平成27年度秋季大会  2015/09
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異導入による酵素特性の変化  [Not invited]
    近藤辰哉; 米山将史; 狩野卓也; 阪本龍司; 石丸 恵
    園芸学会平成27年度春季大会  2015/03
  • ブタE型肝炎ウイルス遺伝子（ORF2）を導入した形質転換体の作出  [Not invited]
    近藤辰哉; 安江 博; 松原悠子; 中川隆生; 石丸 恵
    園芸学会平成26年度秋季大会  2014/09
  • トマトβ-ガラクトシダーゼ４の結晶構造解析  [Not invited]
    石丸 恵; 枝 真広; 多田俊治
    園芸学会平成25年度秋季大会  2013/09
  • 殺菌処理後にactiveMAP貯蔵されたカットレタスおよびカットホウレンソウの微生物的品質と貯蔵性  [Not invited]
    泉 秀実; ヴァラコン リーラヴォラヴォン; 三木秀基; 田口佳秀; 石丸 恵
    日本食品保蔵科学会第60回大会  2011/06  東京農業大学生物産業学部（網走市）  日本食品保蔵科学会第60回大会
     
    カットレタスとホウレンソウに適した抗菌剤で殺菌処理後に，高二酸化炭素を充填したactiveMAP 貯蔵を行い，貯蔵中の微生物的品質と貯蔵性を調査した。
  • バナナ果実（cv. Senorita) におけるアミノ酸からアルコール残酸基の供給経路の解明  [Not invited]
    ウェンダコーン S.K; 石丸 恵; 上田悦範
    日本食品保蔵科学会  2011/06  北海道網走市  日本食品保蔵科学会
  • トマトβ-ガラクトシダーゼ (TBG) ４の結晶化  [Not invited]
    石丸 恵; 枝 真広; 多田俊治
    日本食品保蔵科学会  2011/06  北海道網走市  日本食品保蔵科学会
  • 殺菌処理後にactiveMAP貯蔵されたカットニンジンおよびダイコンの微生物的品質と貯蔵性  [Not invited]
    泉 秀実; 三木秀基; ヴァラコン リーラヴォラヴォン; 村上ゆかり; 石丸 恵
    日本食品保蔵科学会第60回大会  2011/06  東京農業大学生物産業学部（網走市）  日本食品保蔵科学会第60回大会
     
    カットニンジンとダイコンに適した抗菌剤の組合わせで殺菌処理後に，高二酸化炭素を充填するactiveMAP貯蔵を行い，10℃貯蔵中の微生物的品質と貯蔵性を評価した。
  • 酵素剥皮およびナイフ剥皮されたカットカキの微生物叢と品質  [Not invited]
    泉 秀実; 村上ゆかり; 足立卓弥; 石丸 恵; 尾崎嘉彦
    日本食品保蔵科学会第60回大会  2011/06  東京農業大学生物産業学部（網走市）  日本食品保蔵科学会第60回大会
     
    酵素剥皮行程中のカットカキの微生物叢を把握し，ナイフ剥皮されたカットカキと微生物汚染度および品質を比較した。
  • 食の安全・安心について考える～リスク評価・管理からリスクコミュニケーションまで～  [Not invited]
    泉 秀実; 石井 營次; 石丸 恵
    第8回食の安全シンポジウム（和歌山県・近畿大学生物理工学部食品安全工学科）  2011/01  和歌山市  第8回食の安全シンポジウム（和歌山県・近畿大学生物理工学部食品安全工学科）
     
    パネルディスカッション「食の安全・安心について考える～リスク評価・管理からリスクコミュニケーションまで～」において、コーディネーターを務めた。

MISC

Industrial Property Rights

Awards & Honors

  • 日本食品保蔵科学会奨励賞（2006）

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2019/04 -2022/03 
    Author : ISHIAMRU MEGUMI
     
    PpEXP1 from peach fruit has been clarified to be deeply involved in the softening of peach fruit, but the details have not been clarified. In this study, we found that PpEXP1 has hydrolytic activity against cellulose. Furthermore, when cellooligosaccharides were used as substrates, PpEXP1 hydrolyzed cellopentaose to cellobiose and cellotriose, and cellohexasaose to cellobiose and cellotetraose, while it showed no hydrolytic activity for cellobiose to cellotetraose. Small-angle X-ray scattering (SAXS) was also used to clarify the structural change of the cell wall as a structural change of the polymeric structure in fruit softening. The structural changes in the cell wall were observed, and the involvement of PpEXP1 was also clarified.
  • 果実軟化に関与するエクスパンシンの機能解明と分子構造研究
    国立遺伝学研究所：先進ゲノム支援
    Date (from‐to) : 2020/04 -2021/03 
    Author : 石丸 恵
  • 長期貯蔵を目的としたモモ果肉形質の遺伝子多型解析
    東京農業大学生物資源ゲノム解析センター：共同利用・共同研究課題
    Date (from‐to) : 2020/04 -2020/10 
    Author : 石丸 恵
  • 青果物の長距離輸送におけるストレス処理を利用した品質保持技術の検討並びに評価
    文部科学省：科学研究費補助金（基盤研究（B)）
    Date (from‐to) : 2014/04 -2016/03 
    Author : 山内直樹
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2011 -2013 
    Author : Megumi ISHIMARU
     
    In tomato fruit, beta-galactosidase 4 (TBG4) is an enzyme responsible for fruit softening through the degradation of beta-(1,4)-galactan in the pericarp cell wall. To gain structural insight into the substrate specificity, we determined the crystal structures of TBG4 and its complex with beta-D-galactose. TBG4 was composed of a catalytic TIM barrel domain followed by three beta-sandwich domains. This structure is similar to other beta-galactosidase belong to GH35 families.In addition, we determined the enzymatic properties and substrate specificities of TBG1. TBG4 has substrate recognition to beta-(1,4)-linkage, however, TBG1 has beta-(1,3) and beta-(1,6)-likage substrate.In these results, TBG's act on the tomato cell wall during fruits development and maturation, and seberal stage of tomato fruits cell walls construct/reconstruct to some components sugar as a substrate against TBG's.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2010 -2012 
    Author : Naoki YAMAUCHI; Masayoshi SHIGYO; Yoshihiro IMAHORI; Megumi ISHIMARU; Hirofumi TERAI; Yasuo SUZUKI
     
    Effects of stress treatments such as heat, ethanol, UV-B and hydrogen peroxide application on quality maintenance in postharvest horticultural crops were determined by physiological, biochemical and molecular biological analyses. Appropriate conditions of each stress treatment for keeping quality during storage were also studied. These findings obtained suggest that stress treatments make it possible to maintain postharvest storage quality of horticultural crops due to the generation of active oxygen species and the activation of scavenging system, the control of ethylene production, and the maintenance of chemical components. Furthermore, stress treatments seem to lead to novel storage and transport technologies.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2007 -2008 
    Author : Megumi ISHIMARU
     
    本研究は, ブドウ果実の成熟過程に起こる急速な軟化現象を細胞壁構造と細胞壁分解酵素遺伝子の発現から明らかにしようと試みたものである.その結果, ブドウ果実の内部の組織の違いにより軟化過程の速度もしくは構造変化が異なること, ベレゾーン期の急速な軟化は細胞壁のヘミセルロース, 特にキシログルカンの低分子化によって起こるであることが明らかとなった.今後組換えタンパクなどを用いて詳細に調査する必要がある.
  • メロン果実の香気生成酵素遺伝子の単離と解析
  • ブドウ果実の成熟関連遺伝子の単離と解析
  • Cloning and analysis of acetyl Co A transferase gene from melon fruit
  • Cloning and analysis of ripening-related genes from grape berries

Committee Membership

  • 2019 - Today   Senior Editor

Others

  • 2015/04 -2015/04  バイオマテリアルを応用した新規接ぎ木技術の開発とメカニズムの解明 
    近畿大学学内研究助成金 21 世紀研究開発奨励金（共同研究助成金） KD04 研究内容：当該研究課題は，ハイドロキシアパタイト（HAp）ナノ粒子複合体を用いた種々の医療用生体材料による果樹の接ぎ木活着率の向上および活着期間の短縮を目的とした効率的接ぎ木技術の開発とそのメカニズムの解明を目指す．

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