研究者業績

児玉 浩明

コダマ ヒロアキ  (Hiroaki Kodama)

基本情報

所属
千葉大学 大学院園芸学研究院先端園芸工学講座 教授
学位
理学博士(1990年3月 東北大学)

連絡先
kodamafaculty.chiba-u.jp
研究者番号
70302536
J-GLOBAL ID
200901041452137565
researchmap会員ID
1000164465

外部リンク

平成2年3月 東北大学大学院理学研究科 修了、理学博士号 取得
平成 4年9月 民間企業の研究員を経て、九州大学理学部 助手
平成10年4月 千葉大学園芸学部 助教授
平成19年4月 千葉大学園芸学研究科 准教授
平成28年4月 千葉大学園芸学研究科 教授
高等植物のRNAサイレンシングを研究する一方、好熱菌によって発酵された機能性コンポストの生理作用についても研究を進めている。2009年から遺伝子組換え食品等の安全性審査に関わる。


経歴

 1

論文

 120
  • 児玉 浩明
    バイオセーフティ 1(2) 11-17 2024年7月  招待有り筆頭著者責任著者
  • 浅野風斗, 児玉浩明
    アグリバイオ 8 52-53 2024年6月  
  • Taira Miyahara, Hitomi Ohkubo, Yukiko Umeyama, Taichi Oguchi, Takumi Ogawa, Daisaku Ohta, Tomofumi Mochizuki, Hiroaki Kodama
    Food Safety 12(1) 1-16 2024年3月  査読有り最終著者
  • Kayo Ito, Hirokuni Miyamoto, Makiko Matsuura, Chitose Ishii, Yumiko Nakanishi, Wataru Suda, Takashi Satoh, Fuyuko Honda, Atsushi Kurotani, Naoko Tsuji, Teruno Nakaguma, Chie Shindo, Toshiyuki Ito, Ryounosuke Michibata, Ryouichi Yamada, Yosuke Takahashi, Hiroaki Kodama, Jun Kikuchi, Hiroshi Ohno
    Journal of Functional Foods 113 106001-106001 2024年2月  査読有り
  • Takumi Ogawa, Kanae Kato, Harue Asuka, Yumi Sugioka, Tomofumi Mochizuki, Hirokazu Fukuda, Takumi Nishiuchi, Taira Miyahara, Hiroaki Kodama, Daisaku Ohta
    Plant Biotechnology 2024年  
  • Takumi Ogawa, Kanae Kato, Harue Asuka, Yumi Sugioka, Tomofumi Mochizuki, Takumi Nishiuchi, Taira Miyahara, Hiroaki Kodama, Daisaku Ohta
    Food Safety 2023年9月  査読有り
  • Hirokuni Miyamoto, Katsumi Shigeta, Wataru Suda, Yasunori Ichihashi, Naoto Nihei, Makiko Matsuura, Arisa Tsuboi, Naoki Tominaga, Masahiko Aono, Muneo Sato, Shunya Taguchi, Teruno Nakaguma, Naoko Tsuji, Chitose Ishii, Teruo Matsushita, Chie Shindo, Toshiaki Ito, Tamotsu Kato, Atsushi Kurotani, Hideaki Shima, Shigeharu Moriya, Satoshi Wada, Sankichi Horiuchi, Takashi Satoh, Kenichi Mori, Takumi Nishiuchi, Hisashi Miyamoto, Hiroaki Kodama, Masahira Hattori, Hiroshi Ohno, Jun Kikuchi, Masami Yokota Hirai
    ISME Communications 3(1) 2023年3月31日  査読有り
    Abstract Compost is used worldwide as a soil conditioner for crops, but its functions have still been explored. Here, the omics profiles of carrots were investigated, as a root vegetable plant model, in a field amended with compost fermented with thermophilic Bacillaceae for growth and quality indices. Exposure to compost significantly increased the productivity, antioxidant activity, color, and taste of the carrot root and altered the soil bacterial composition with the levels of characteristic metabolites of the leaf, root, and soil. Based on the data, structural equation modeling (SEM) estimated that amino acids, antioxidant activity, flavonoids and/or carotenoids in plants were optimally linked by exposure to compost. The SEM of the soil estimated that the genus Paenibacillus and nitrogen compounds were optimally involved during exposure. These estimates did not show a contradiction between the whole genomic analysis of compost-derived Paenibacillus isolates and the bioactivity data, inferring the presence of a complex cascade of plant growth-promoting effects and modulation of the nitrogen cycle by the compost itself. These observations have provided information on the qualitative indicators of compost in complex soil-plant interactions and offer a new perspective for chemically independent sustainable agriculture through the efficient use of natural nitrogen.
  • Taira Miyahara, Takumi Nishiuchi, Nao Fujikawa, Taichi Oguchi, Akira Kikuchi, Ken-ichiro Taoka, Takumi Ogawa, Karuna Honda, Yube Yamaguchi, Tomofumi Mochizuki, Daisaku Ohta, Hiroaki Kodama
    Food Safety 2023年3月  査読有り最終著者
  • Futo Asano, Arisa Tsuboi, Shigeharu Moriya, Tamotsu Kato, Naoko Tsuji, Teruno Nakaguma, Hiroshi Ohno, Hirokuni Miyamoto, Hiroaki Kodama
    Journal of Applied Microbiology 134(1) 2023年1月  査読有り最終著者責任著者
    Abstract Aims Hercules beetle is a popular pet and large adult individuals are considered valuable. Incorporating compost prepared from marine animals and fermented by thermophilic bacteria into the humus benefits the gut microflora of several livestock. Here, we evaluated whether this compost improves the growth of the Hercules beetle (Dynastes hercules hercules) larvae. Methods and Results We mixed the compost grains with the humus at a final concentration of 1% (w/w) and transferred ∼90 days old Hercules beetle larvae to fresh humus with or without the compost. After 72 days rearing period, only the female larvae reared in the humus with compost exhibited superior growth, compared with those grown in compost-free humus. The gut bacterial composition was determined at 0 and 46 day after transferring the larvae to humus with or without compost. Improved growth of the female larvae was associated with increased abundance of Mollicutes and decreased abundance of Gammaproteobacteria. Conclusion The thermophile-fermented compost has a probiotic effect on the female Hercules beetle larvae that is mediated by altered gut microflora.
  • Kayo Ito, Hirokuni Miyamoto, Makiko Matsuura, Chitose Ishii, Arisa Tsuboi, Naoko Tsuji, Teruno Nakaguma, Yumiko Nakanishi, Tamotsu Kato, Wataru Suda, Fuyuko Honda, Toshiyuki Ito, Shigeharu Moriya, Hideaki Shima, Ryounosuke Michibata, Ryouichi Yamada, Yosuke Takahashi, Hirohisa Koga, Hiroaki Kodama, Yuko Watanabe, Jun Kikuchi, Hiroshi Ohno
    Journal of Bioscience and Bioengineering 134(2) 105-115 2022年6月  査読有り
    Weizmannia coagulans SANK70258 is a spore-forming thermostable lactic acid bacterium and an effective probiotic for the growth of livestock animals, but its growth-promoting mechanism remains unclear. Here, the composition of fecal metabolites in broilers continuously administered with W. coagulans SANK70258 was assessed under a regular program with antibiotics, which was transiently given for 6 days after birth. Oral administration of W. coagulans to broiler chicks tended to increase the average daily gain of body weights thereafter. The composition of fecal metabolites in the early chick stage (day 10 after birth) was dramatically altered by the continuous exposure. The levels of short-chain fatty acids (SCFAs) propionate and butyrate markedly increased, while those of acetate, one of the SCFAs, and lactate were reduced. Simultaneously, arabitol, fructose, mannitol, and erythritol, which are carbohydrates as substrates for gut microbes to produce SCFAs, also increased along with altered correlation. Correlation network analyses classified the modularity clusters (|r| > 0.7) among carbohydrates, SCFAs, lactate, amino acids, and the other metabolites under the two conditions. The characteristic diversities by the exposure were visualized beyond the perspective associated with differences in metabolite concentrations. Further, enrichment pathway analyses showed that metabolic composition related to biosynthesis and/or metabolism for SCFAs, amino acids, and energy were activated. Thus, these observations suggest that W. coagulans SANK70258 dramatically modulates the gut metabolism of the broiler chicks, and the metabolomics profiles during the early chick stages may be associated with growth promotion.
  • Hirokuni Miyamoto, Futo Asano, Koutarou Ishizawa, Wataru Suda, Hisashi Miyamoto, Naoko Tsuji, Makiko Matsuura, Arisa Tsuboi, Chitose Ishii, Teruno Nakaguma, Chie Shindo, Tamotsu Kato, Atsushi Kurotani, Hideaki Shima, Shigeharu Moriya, Masahira Hattori, Hiroaki Kodama, Hiroshi Ohno, Jun Kikuchi
    The Science of the total environment 836 155520-155520 2022年5月1日  査読有り
    Effective biological utilization of wood biomass is necessary worldwide. Since several insect larvae can use wood biomass as a nutrient source, studies on their digestive microbial structures are expected to reveal a novel rule underlying wood biomass processing. Here, structural inferences for inhabitant bacteria involved in carbon and nitrogen metabolism for beetle larvae, an insect model, were performed to explore the potential rules. Bacterial analysis of larval feces showed enrichment of the phyla Chroloflexi, Gemmatimonadetes, and Planctomycetes, and the genera Bradyrhizobium, Chonella, Corallococcus, Gemmata, Hyphomicrobium, Lutibacterium, Paenibacillus, and Rhodoplanes, bacteria potential involved in plant growth promotion, nitrogen cycle modulation, and/or environmental protection. The fecal abundances of these bacteria were not necessarily positively correlated with their abundances in the habitat, indicating that they were selectively enriched in the feces of the larvae. Association analysis predicted that common fecal bacteria might affect carbon and nitrogen metabolism. Based on these hypotheses, structural equation modeling (SEM) statistically estimated that inhabitant bacterial groups involved in carbon and nitrogen metabolism were composed of the phylum Gemmatimonadetes and the genera Bradyrhizobium, Corallococcus, and Gemmata, which were among the fecal-enriched bacteria. Nevertheless, the selected common bacteria, i.e., the phyla Acidobacteria, Armatimonadetes, and Bacteroidetes and the genera Candidatus Solibacter, Fimbriimonas, Gemmatimonas, Sphingobium, and Methanobacterium, were necessary to obtain good fit indices in the SEM. In addition, the composition of the bacterial groups differed depending upon metabolic targets, carbon and nitrogen, and their stable isotopes, δ13C and δ15N, respectively. Thus, the statistically derived causal structural models highlighted that the larval fecal-enriched bacteria and common symbiotic bacteria might selectively play a role in wood biomass carbon and nitrogen metabolism. This information could confer a new perspective that helps us use wood biomass more efficiently and might stimulate innovation in environmental industries in the future.
  • 宮本浩邦, 大野博司, 児玉浩明
    JATAFFジャーナル 10(5) 37-44 2022年5月  招待有り最終著者
  • Yudai Inabu, Yutaka Taguchi, Hirokuni Miyamoto, Tetsuji Etoh, Yuji Shiotsuka, Ryoichi Fujino, Toru Okada, Motoaki Udagawa, Naoko Tsuji, Makiko Matsuura, Arisa Tsuboi, Tamotsu Kato, Hiroaki Kodama, Hiroshi Ohno, Hideyuki Takahashi
    Journal of applied microbiology 132(5) 3870-3882 2022年5月  査読有り
    AIMS: Probiotic effects of compost containing thermophiles on productivity have been reported in domestic animals, although not cattle. We evaluated the effects of administering Caldibacillus hisashii, a thermophile contained in compost, on growth, blood components, faecal organic acid concentrations and microbiota population in Japanese black calves. METHODS AND RESULTS: Calves were administered C. hisashii from 3 to 5 months of age. Administering C. hisashii decreased feed intake without affecting body weight, indicating that feed efficiency is improved by administration. Administering C. hisashii decreased plasma insulin concentration without affecting glucose and non-esterified fatty acid concentrations. Chao1 was decreased by exposure at 5 months of age. Similarly, weighted and unweighted UniFrac distances were affected by treatment at 5 months of age. Faecal abundance of the phylum Bacteroidetes tended to be increased by exposure. Faecal propionic acid concentration was correlated positively with faecal abundance of phylum Bacteroidetes but negatively with that of Firmicutes. Interestingly, the population of the genus Methanobrevibacter, representing the majority of methanogens, was lowered by exposure and was negatively correlated with faecal propionic acid concentration. CONCLUSION: Administration of C. hisashii has the potential to improve growth performance of Japanese black calves and to contribute to reducing environmental load, which may be associated with altered endocrine kinetics and gut microbial populations. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that isolated thermophiles included in compost may exert probiotic effects on calves.
  • Hiroaki Kodama, Yukiko Umeyama, Taira Miyahara, Taichi Oguchi, Takashi Tsujimoto, Yoshihiro Ozeki, Takumi Ogawa, Yube Yamaguchi, Daisaku Ohta
    Food Safety 10(1) 13-31 2022年  査読有り筆頭著者責任著者
  • Hiroaki Kodama, Taira Miyahara, Taichi Oguchi, Takashi Tsujimoto, Yoshihiro Ozeki, Takumi Ogawa, Yube Yamaguchi, Daisaku Ohta
    Food Safety 9(2) 32-47 2021年6月  査読有り筆頭著者責任著者
    Grafting of non-transgenic scion onto genetically modified (GM) rootstocks provides superior agronomic traits in the GM rootstock, and excellent fruits can be produced for consumption. In such grafted plants, the scion does not contain any foreign genes, but the fruit itself is likely to be influenced directly or indirectly by the foreign genes in the rootstock. Before market release of such fruit products, the effects of grafting onto GM rootstocks should be determined from the perspective of safety use. Here, we evaluated the effects of a transgene encoding β-glucuronidase (GUS) on the grafted tomato fruits as a model case. An edible tomato cultivar, Stella Mini Tomato, was grafted onto GM Micro-Tom tomato plants that had been transformed with the GUS gene. The grafted plants showed no difference in their fruit development rate and fresh weight regardless of the presence or absence of the GUS gene in the rootstock. The fruit samples were subjected to transcriptome (NGS-illumina), proteome (shotgun LC-MS/MS), metabolome (LC-ESI-MS and GC-EI-MS), and general food ingredient analyses. In addition, differentially detected items were identified between the grafted plants onto rootstocks with or without transgenes (more than two-fold). The transcriptome analysis detected approximately 18,500 expressed genes on average, and only 6 genes were identified as differentially expressed. Principal component analysis of 2,442 peaks for peptides in proteome profiles showed no significant differences. In the LC-ESI-MS and GC-EI-MS analyses, a total of 93 peak groups and 114 peak groups were identified, respectively, and only 2 peak groups showed more than two-fold differences. The general food ingredient analysis showed no significant differences in the fruits of Stella scions between GM and non-GM Micro-Tom rootstocks. These multiple omics data showed that grafting on the rootstock harboring the GUS transgene did not induce any genetic or metabolic variation in the scion.
  • Haruka Sagi, Shuichi Shibuya, Tamotsu Kato, Yumiko Nakanishi, Arisa Tsuboi, Shigeharu Moriya, Hiroshi Ohno, Hirokuni Miyamoto, Hiroaki Kodama, Takahiko Shimizu
    Experimental gerontology 130 110795-110795 2020年2月  査読有り
    Redox imbalance induces oxidative damage and causes age-related pathologies. Mice lacking the antioxidant enzyme SOD1 (Sod1-/-) exhibit various aging-like phenotypes throughout the body and are used as aging model mice. Recent reports suggested that age-related changes in the intestinal environment are involved in various diseases. We investigated cecal microbiota profiles and gastrointestinal metabolites in wild-type (Sod1+/+) and Sod1-/- mice. Firmicutes and Bacteroidetes were dominant in Sod1+/+ mice, and most of the detected bacterial species belong to these two phyla. Meanwhile, the Sod1-/- mice had an altered Firmicutes and Bacteroidetes ratio compared to Sod1+/+ mice. Among the identified genera, Paraprevotella, Prevotella, Ruminococcus, and Bacteroides were significantly increased, but Lactobacillus was significantly decreased in Sod1-/- mice compared to Sod1+/+ mice. The correlation analyses between cecal microbiota and liver metabolites showed that Bacteroides and Prevotella spp. were grouped into the same cluster, and Paraprevotella and Ruminococcus spp. were also grouped as another cluster. These four genera showed a positive and a negative correlation with increased and decreased liver metabolites in Sod1-/- mice, respectively. In contrast, Lactobacillus spp. showed a negative correlation with increased liver metabolites and a positive correlation with decreased liver metabolites in Sod1-/- mice. These results suggest that the redox imbalance induced by Sod1 loss alters gastrointestinal microflora and metabolites.
  • Mayuko Shimokawa, Sayaka Hirai, Hiroaki Kodama
    Plant Biotechnology Reports 13(2) 193-199 2019年4月7日  査読有り
  • Tatsuya Mikami, Yuta Saeki, Sayaka Hirai, Mayuko Shimokawa, Yukiko Umeyama, Yusaku Kuroda, Hiroaki Kodama
    Plant Biotechnology Reports 12(6) 389-397 2018年12月30日  査読有り
  • 宮本浩邦, 児玉浩明, 大野博司
    畜産技術 18-22 2018年11月  
  • Shota Yoshikawa, Ryosuke Araoka, Yu Kajihara, Toshiyuki Ito, Hirokuni Miyamoto, Hiroaki Kodama
    Journal of Bioscience and Bioengineering 125(5) 519-524 2018年5月1日  査読有り
    Megasphaera elsdenii is able to produce several short-chain fatty acids (SCFAs), such as acetate, propionate, butyrate, and valerate. These SCFAs serve as an energy source for host animals and play an important role in gut health. In this study, M. elsdenii was isolated from pig feces that had been collected from two farms located in distinct areas of Japan. These M. elsdenii isolates were genotyped, and 7 representative strains were selected. When these 7 strains and M. elsdenii JCM 1772T were cultured with lactate for 24 h, all 7 strains produced valerate as a predominant SCFA. Therefore, the valerate-producing M. elsdenii inhabits a wide area of Japan. In contrast, M. elsdenii JCM 1772T produced acetate, propionate, butyrate, and valerate at similar levels. When the Y2 strain, one of the 7 representative strains, was cultured without lactate, low levels of valerate accumulated. In contrast, in a time course of lactate fermentation by the Y2 strain, lactate was rapidly consumed, and acetate and propionate were produced after 6 h of incubation. Thereafter, acetate and propionate were consumed from 6 to 12 h after the start of the incubation, and valerate and butyrate were produced. In most of the previously described M. elsdenii strains, valerate was not a predominant SCFA. Therefore, the M. elsdenii Y2 strain showed an unique metabolism in which valerate was produced as a primary end product of lactate fermentation.
  • Sayuri Ohta, Sakie Nakagawara, Sayaka Hirai, Kumi Miyagishima, Gorou Horiguchi, Hiroaki Kodama
    Plant Biotechnology Reports 12(2) 105-114 2018年4月1日  査読有り
  • 宮本浩邦, 宮本久, 田代幸寛, 酒井謙二, 児玉浩明
    Pig Journal 79-81 2018年4月  
  • 宮本浩邦, 宮本久, 田代幸寛, 酒井謙二, 児玉浩明
    生物工学会誌 96 56-63 2018年1月  招待有り
  • Yu Kajihara, Shota Yoshikawa, Yuichiro Cho, Toshiyuki Ito, Hirokuni Miyamoto, Hiroaki Kodama
    Anaerobe 48 160-164 2017年12月1日  査読有り
    Lactic acid produced by intestinal bacteria is fermented by lactate-utilizing bacteria. In this study, we developed a selective culture medium (KMI medium) for Megasphaera elsdenii, a lactate-utilizing bacterium that is abundant in pig intestines. Supplementation of the medium with lactate and beef extract powder was necessary for the preferential growth of M. elsdenii. In addition, we designed a species-specific primer set to detect M. elsdenii. When pig fecal samples were plated on KMI agar medium, approximately 60–100% of the resulting colonies tested positive using the M. elsdenii-specific PCR primers. In fact, nearly all of the large, yellow-white colonies that grew on the KMI agar medium tested positive by PCR with this primer set. The 16S rRNA gene sequences of three representative PCR-positive strains showed strong similarities to that of M. elsdenii ATCC 25940T (98.9–99.2% identity). These three strains were approximately 1.5 μm sized cocci that were primarily arranged in pairs, as was observed for M. elsdenii JCM 1772T. The selective KMI medium and species-specific primer set developed in this study are useful for the isolation and detection of M. elsdenii and will be useful in research aimed at increasing our understanding of intestinal short-chain fatty acid metabolism in pigs.
  • Mayuko Koizumi, Yumi Shimotori, Yuta Saeki, Sayaka Hirai, Shin-ichiro Oka, Hiroaki Kodama
    PLANT MOLECULAR BIOLOGY REPORTER 35(2) 265-272 2017年4月  査読有り
    The Cucumber mosaic virus (CMV) 2b protein has multiple activities as a viral suppressor of RNA silencing (VSR). Here, we characterized the 2b protein (IA2b) of a CMV-IA isolate. This IA2b protein has two nuclear localization signals, and when it was fused with GFP, the protein was found to be preferentially localized in the nucleus. A transgenic tobacco line, 2b8, expressing the IA2b gene showed an enhanced expression of an agroinfiltrated sense transgene, which indicated that IA2b has VSR activity. When 2b8 plants were crossed with plants showing sense-transgene-induced post-transcriptional gene silencing (S-PTGS), the IA2b protein caused the disappearance of small interfering RNAs (siRNAs) and the S-PTGS phenotype was converted to the overexpression phenotype. When 2b8 plants were crossed with plants showing inverted repeat-induced post-transcriptional gene silencing (IR-PTGS), the IA2b protein did not suppress the accumulation of siRNAs processed from hairpin RNAs and the silencing phenotype was maintained. When a tobacco plant showing an overexpressed phenotype of a sense transgene was crossed with IR-PTGS plants targeting the same transgene, the primary siRNAs that were produced by the IR-PTGS construct triggered the production of the secondary siRNAs through the RNA-dependent RNA polymerase6 (RDR6)-dependent pathway. The IA2b protein suppressed the secondary siRNA formation but not the primary siRNA production from hairpin RNAs, resulting in the silencing phenotype from IR-PTGS being maintained. These results indicate that IA2b suppresses RDR6-dependent siRNA production and does not interfere with the silencing step by siRNA-guided RNA degradation.
  • Miki Noda, Mika Nakamura, Ryuichi Takamiya, Takashi Tamura, Toshiyuki Ito, Hiroaki Kodama
    Biochimie Open 2 24-32 2016年6月1日  査読有り
    An enzyme, O-acetylserine(thiol)lyase (OASTL), also known as O-acetylserine sulfhydrylase or cysteine synthase (CSase), catalyses the incorporation of sulfide into O-acetylserine and produces cysteine. We previously identified a cDNA encoding an OASTL-like protein from Spinacia oleracea, (SoCSaseLP), but a recombinant SoCSaseLP produced in Escherichia coli did not show OASTL activity. The exon-intron structure of the SoCSaseLP gene shared conserved structures with other spinach OASTL genes. The SoCSaseLP and a Beta vulgaris homologue protein, KMT13462, comprise a unique clade in the phylogenetic tree of the OASTL family. Interestingly, when the SoCSaseLP gene was expressed in tobacco plants, total OASTL activity in tobacco leaves was reduced. This reduction in total OASTL activity was most likely caused by interference by SoCSaseLP with cytosolic OASTL. To investigate the possible interaction of SoCSaseLP with a spinach cytosolic OASTL isoform SoCSaseA, a pull-down assay was carried out. The recombinant glutathione S-transferase (GST)-SoCSaseLP fusion protein was expressed in E. coli together with the histidine-tagged SoCSaseA protein, and the protein extract was subjected to glutathione affinity chromatography. The histidine-tagged SoCSaseA was co-purified with the GST-SoCSaseLP fusion protein, indicating the binding of SoCSaseLP to SoCSaseA. Consistent with this interaction, the OASTL activity of the co-purified SoCSaseA was reduced compared with the activity of SoCSaseA that was purified on its own. These results strongly suggest that SoCSaseLP negatively regulates the activity of other cytosolic OASTL family members by direct interaction.
  • Toshiyuki Ito, Hirokuni Miyamoto, Yoshifumi Kumagai, Motoaki Udagawa, Toshihito Shinmyo, Kenichi Mori, Kazuo Ogawa, Hisashi Miyamoto, Hiroaki Kodama
    JOURNAL OF BIOSCIENCE AND BIOENGINEERING 121(6) 659-664 2016年6月  査読有り
    Recently, we reported that the oral administration of an extract of compost fermented with marine animal resources and thermophilic Bacillus species should confer health benefits in fish, pigs and rodents. Herein, the relations between fecundity and gut metabolites in laying hens and pigs on farms after oral exposure to compost were investigated. On the hen farms, the egg production of hens continuously administered the extract was maintained at significantly higher levels compared with the hens not administered the extract. On the swine farms, after the compost treatment, the shipping dates of fattening pigs were shortened, with an improvement in the death rate of the pigs. When the levels of fecal organic acids, such as short-chain fatty acids, lactate, and ammonium, as indicators of gut metabolism and energy sources for peripheral tissues, were examined, the levels of the acetate, propionate, and butyrate in the feces of the hens and pigs in the compost-treated group were not always different from those in the untreated control group. However, the levels of lactate were consistently low in the feces of both animals after the compost treatment. The fecal ammonium concentrations in old hens (age 597-672 days) and 2-month-old piglets from the compost-fed mother sows were low when compared with the untreated groups. The concentrations of free organic acids and their related compounds in the animal products (eggs and pig loins) were nearly equal to those in the untreated control products. Thus, the oral administration of the thermophile-fermented compost should improve the fecundity of hens and pigs by modifying their gut metabolism. 2015 The Society for Biotechnology, Japan. All rights reserved.
  • Ryusuke Tanaka, Hirokuni Miyamoto, Shin-ichi Inoue, Kazuhiro Shigeta, Masakazu Kondo, Toshiyuki Ito, Hiroaki Kodama, Hisashi Miyamoto, Teruo Matsushita
    JOURNAL OF BIOSCIENCE AND BIOENGINEERING 121(5) 530-535 2016年5月  査読有り
    Recently, a compost fermented with marine animals with thermophilic Bacillaceae in a clean and exclusive process at high temperature was reported as a possible feed additive to improve the healthy balance in sea fish and mammals (i.e., pigs and rodents). Here, the effects of the oral administration of the compost on the muscle and internal organs of carp (Cyprinus carpio) as a freshwater fish model were investigated. The fatty acid composition was different in the muscle of the carp fed with or without the compost extract, but there was little difference in the hepatopancreas. The accumulation of triacylglycerols, cholesterol, lipid peroxide and hydroxyl lipids decreased in the muscle after the oral administration of the compost extract in the carps over 12 weeks, but the accumulation did not always decrease in the hepatopancreas. In contrast, free-radical-scavenging activities and the concentrations of free amino acids in the muscle did not always increase and was dependent on the dose of the compost at 12 weeks. The scavenging activities and part of free amino acid levels in the muscle of the carp were improved at 24 weeks after a high dose of compost exposure, and then the survival rates of the carp were maintained. Thus, the oral administration of thermophile-fermented compost can prevent peroxidation and increase the content of free amino acids in the muscle of the freshwater fish, depending on the dose and term of the administration, and may be associated with the viability of the fish. (C) 2015, The Society for Biotechnology, Japan. All rights reserved.
  • Yo Maruyama, Toshiyuki Ito, Hiroaki Kodama, Akira Matsuura
    PLOS ONE 11(3) e0151894 2016年3月  査読有り
    The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of nonessential amino acids to a synthetic defined (SD) medium increases maximal cell growth and extends the chronological lifespan. The positive effects of amino acids can be reproduced by modulating the medium pH, indicating that amino acids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the amino acid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential amino acids may cause alterations in environmental conditions.
  • 枡岡 久志, 宮本 浩邦, 須田 瓦, 宇田川 元章, 井藤 俊行, 岩田 菖子, 大野 博司, 服部 正平, 児玉 浩明
    ペット栄養学会誌 19 suppl_30-suppl_31 2016年  
    近年、プロバイオティクスやプレバイオティクスへの関心が高まっているが、ペッ ト業界では犬の腸内細菌叢や代謝に与える影響についての研究は限られている。本研究では、畜産分野で利用研究が進んでいる Bacillus thermoamylovoraus の近縁種である好熱性細菌 Bacillus hisashii N11T(国際寄託番号BP-863)の経口投与試験を実施し、血中成分、内臓脂肪の変化、 並びに腸内細菌叢の生理的な変化について検討した。<br> 腸内細菌叢の解析の結果、投与後に Firmicutes門の構成比が減少し、Bacteroides門の構成比が増加していた。また、Firmicutes門の中でも特に Clostridium属Cluster XIに属する種が減少していた。この時、CT画像の解析の結果、脂肪領域の減少が確認され、併せて血中の脂肪代謝に関連する分子の変化が確認された。
  • Ayaka Nishida, Hirokuni Miyamoto, Sankichi Horiuchi, Ryo Watanabe, Hidetoshi Morita, Shinji Fukuda, Hiroshi Ohno, Shizuko Ichinose, Hisashi Miyamoto, Hiroaki Kodama
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 65(11) 3944-3949 2015年11月  査読有り
    A taxonomic study was performed on 15 bacterial isolates from the caeca of gnotobiotic mice that had been fed with thermophile-fermented compost. The 15 isolates were thermophilic, Gram-stain-positive, facultatively anaerobic, endospore-forming bacteria, and were most closely related to Bacillus thermoamylovorans CNCM I-1378(T). The 16S rRNA gene sequence of strain N-11(T), selected as representative of this new group, showed a similarity of 99.4 % with Bacillus thermoamylovorans CNCM I-1378(T), 94.7 % with Bacillus thermolactis R-6488(T), and 94.4 % with Bacillus kokeshiiformis MO-04(T). The isolates were then classified into two distinct groups based on a (GTG) 5-fingerprint analysis. Two isolates, N-11(T) and N-21, were the representatives of these two groups, respectively. The N-11(T) and N-21 isolates showed 66-71 % DNA-DNA relatedness with one other, but had less than 37 % DNA-DNA relatedness with B. thermoamylovorans LMG 18084(T). The other 13 isolates showed DNA-DNA relatedness values above 74 % with the N-11(T) isolate. All 15 isolates grew at 25-60 degrees C (optimum 50 degrees C), pH 6-8 (optimum pH 7) and were capable of growing on a medium containing 6 % (w/v) NaCl (optimum 0.5 %). The 15 isolates could be distinguished from B. thermoamylovorans LMG 18084(T) because they showed Tween 80 hydrolysis activity and did not produce acid from melibiose. The major fatty acids were anteiso-C-15 : 0, C-16 : 0, iso-C-15 : 0, iso-C-14 : 0 and iso-C-16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and several unidentified phospholipids. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The menaquinone was MK-7. The DNA G + C content was 37.9 mol%. Based on the phenotypic properties, the 15 strains represent a novel species of the genus Bacillus, for which the name Bacillus hisashii sp. nov. is proposed. The type strain is N-11(T) (=NRBC 110226(T) =LMG 28201(T)).
  • Mi-Rae Shin, Masaya Natsuume, Takashi Matsumoto, Mitsumasa Hanaoka, Misaki Imai, Ken Iijima, Shin-ichiro Oka, Eri Adachi, Hiroaki Kodama
    PLOS ONE 9(2) e87869 2014年2月  査読有り
    Sense transgene-induced post-transcriptional gene silencing (S-PTGS) is thought to be a type of RNA silencing in which ARGONAUTE1 directs the small interfering RNA (siRNA)-mediated cleavage of a target mRNA in the cytoplasm. Here, we report that the altered splicing of endogenous counterpart genes is a main cause for the reduction of their mature mRNA levels. After the S-PTGS of a tobacco endoplasmic reticulum omega-3 fatty acid desaturase (NtFAD3) gene, 3'-truncated, polyadenylated endo-NtFAD3 transcripts and 5'-truncated, intron-containing endo-NtFAD3 transcripts were detected in the total RNA fraction. Although transcription proceeded until the last exon of the endogenous NtFAD3 gene, intron-containing NtFAD3 transcripts accumulated in the nucleus of the S-PTGS plants. Several intron-containing NtFAD3 transcripts harboring most of the exon sequences were generated when an endogenous silencing suppressor gene, rgs-CaM, was overexpressed in the S-PTGS plants. These intron-containing NtFAD3 splice variants were generated in the presence of NtFAD3 siRNAs that are homologous to the nucleotide sequences of these splice variants. The results of this study indicate that the inhibition of endo-NtFAD3 gene expression is primarily directed via the alteration of splicing and not by cytoplasmic slicer activity. Our results suggest that the transgene and intron-containing endogenous counterpart genes are differentially suppressed in SPTGS plants.
  • Haruna Nakamura, Mi-Rae Shin, Takako Fukagawa, Mami Arita, Tatsuya Mikami, Hiroaki Kodama
    PLANT CELL TISSUE AND ORGAN CULTURE 116(1) 47-53 2014年1月  査読有り
    A tobacco calmodulin-related protein, rgs-CaM, interacts with viral suppressors of RNA silencing and modulates host RNA silencing. Plants overexpressing the rgs-CaM gene were crossed with plants exhibiting sense transgene-induced RNA silencing (S-PTGS) or inverted repeat-induced RNA silencing (IR-PTGS). S44 plants harboring a sense transgene encoding a tobacco microsomal omega-3 fatty acide desaturase (NtFAD3) exhibited the S-PTGS phenotype. The frequency of the S-PTGS phenotype incidence was nearly 100 % in the hemizygous S44 plants, but was reduced to 30 % in crossbred plants with an rgs-CaM-overexpressing transgenic line. The remaining 70 % of crossbred plants successfully overexpressed the NtFAD3 transgene, and the amount of NtFAD3 small interfering RNAs (siRNAs) was largely decreased. In contrast, overexpression of rgs-CaM did not suppress siRNA production in the IR-PTGS that targeted the NtFAD3 gene. These results indicated that rgs-CaM suppresses RNA silencing at a step upstream of siRNA production and does not interfere with the later steps of RNA silencing, including siRNA-mediated RNA degradation.
  • Naoko Saruyama, Yurina Sakakura, Tomoya Asano, Takumi Nishiuchi, Hamako Sasamoto, Hiroaki Kodama
    ANALYTICAL BIOCHEMISTRY 441(1) 58-62 2013年10月  査読有り
    The metabolic activity of suspension cultures of Sonneratia alba cells was quantified by measurement of the hydrolysis of fluorescein diacetate (FDA). FDA is incorporated into live cells and is converted into fluorescein by cellular hydrolysis. Aliquots (0.1-0.75 g) of S. alba cells were incubated with FDA at a final concentration of 222 mu g/ml suspension for 60 min. Hydrolysis was stopped, and fluorescein was extracted by the addition of acetone and quantified by measurement of absorbance at 490 nm. Fluorescein was produced linearly with time and cell weight. Cells of S. alba are halophilic and proliferated well in medium containing 50 and 100 mM NaCl. Cells grown in medium containing 100 mM NaCl showed 2- to 3-fold higher FDA hydrolysis activity than those grown in NaCl-free medium. When S. alba cells grown in medium supplemented with 50 mM NaCl were transferred to fresh medium containing 100 mM mannitol, cellular FDA hydrolysis activity was down-regulated after 4 days of culture, indicating that the moderately halophilic S. alba cells were sensitive to osmotic stress. Quantification of cellular metabolic activity via the in vivo FDA hydrolysis assay provides a simple and rapid method for the determination of cellular activity under differing culture conditions. (c) 2013 Elsevier Inc. All rights reserved.
  • Miyamoto H, Shimada E, Satoh T, Tanaka R, Oshima K, Suda W, Fukuda S, Nishiuchi T, Matsuura M, Mori K, Miyamoto H, Ohno H, Hattori M, Kodama H, Matsushita T
    Journal of bioscience and bioengineering 116(2) 203-208 2013年8月  査読有り
  • H. Miyamoto, M. Seta, S. Horiuchi, Y. Iwasawa, T. Naito, A. Nishida, H. Miyamoto, T. Matsushita, K. Itoh, H. Kodama
    JOURNAL OF APPLIED MICROBIOLOGY 114(4) 1147-1157 2013年4月  査読有り
    Aims The oral administration of a compost produced by the fermentation of marine animals with thermophiles confers health benefits for fish and pigs. This study aimed to isolate the beneficial bacteria from this compost that would modulate the physiological conditions of host animals. Methods and Results The compost extract was orally administrated to germ-free mice for 21days, and thereafter, the culturable bacterial population within the caeca was surveyed. Sequence analyses of the 16S rRNA gene from the two predominant thermophilic isolates revealed organisms that were closely related to Bacillus thermoamylovorans and Bacillus coagulans. These bacteria could grow at 37 degrees C, but more abundantly at 5055 degrees C, and they were minor components of the original compost extract. When an individual bacterial strain or a mixture of strains was administered to the conventionally maintained mice, their levels of faecal immunoglobulin A, an indicator of the gut immune response, were markedly raised. In addition, their feeding efficiency also changed among the tested mouse groups. Conclusions These two kinds of thermophilic bacterial species, isolated from the caeca after compost ingestion to the germ-free mice, are candidate probiotics that could function in the mammalian gut. Significance and Impact of the Study This study revealed that the compost used in agriculture can contain potential probiotic thermophiles.
  • Kazuto Ishikawa, Takashi Ohmori, Hirokuni Miyamoto, Toshiyuki Ito, Yoshifumi Kumagai, Masatoshi Sonoda, Jirou Matsumoto, Hisashi Miyamoto, Hiroaki Kodama
    APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 97(3) 1349-1359 2013年2月  査読有り
    NO (3) (-) is a major nitrogen source for plant nutrition, and plant cells store NO (3) (-) in their vacuoles. Here, we report that a unique compost made from marine animal resources by thermophiles represses NO (3) (-) accumulation in plants. A decrease in the leaf NO (3) (-) content occurred in parallel with a decrease in the soil NO (3) (-) level, and the degree of the soil NO (3) (-) decrease was proportional to the compost concentration in the soil. The compost-induced reduction of the soil NO (3) (-) level was blocked by incubation with chloramphenicol, indicating that the soil NO (3) (-) was reduced by chloramphenicol-sensitive microbes. The compost-induced denitrification activity was assessed by the acetylene block method. To eliminate denitrification by the soil bacterial habitants, soil was sterilized with gamma irradiation and then compost was amended. After the 24-h incubation, the N2O level in the compost soil with presence of acetylene was approximately fourfold higher than that in the compost soil with absence of acetylene. These results indicate that the low NO (3) (-) levels that are often found in the leaves of organic vegetables can be explained by compost-mediated denitrification in the soil.
  • Takashi Satoh, Takumi Nishiuchi, Tomoaki Naito, Teruo Matsushita, Hiroaki Kodama, Hisashi Miyamoto, Hirokuni Miyamoto
    JOURNAL OF BIOSCIENCE AND BIOENGINEERING 114(5) 500-505 2012年11月  査読有り
    Oral administration of an extract consisting of compost fermented with thermophiles to pigs reduces the incidence of stillbirth and promotes piglet growth. However, the mechanism by which the compost extract modulates the physiological conditions of the animals remains largely unknown. Here, we investigate the effects of compost extract on the physiological responses in the intestine of a mammalian rat model. The level of fecal immunoglobulin A (IgA), which provides protection against pathogens and is secreted from the small intestine, was significantly higher in rats treated with continuous administration of the compost extract than in untreated rats after 2 months, but not after 1 month. However, the fecal IgA level was not significantly different in rats that received the filtered compost extract compared with the untreated rats or the rats that received the compost extract. Gene expression analyses of the small intestine indicated that several immune-related genes were upregulated following compost exposure. Specifically, the expression levels of lymphocyte chemoattractant chemokine CXCL13 and Granzyme B, which is released within cytotoxic T lymphocytes and natural killer cells, increased in the small intestinal tract following compost exposure. Based on these observations, it was postulated that the increased level of fecal IgA following compost exposure was associated with the expression of CXCL13 and Granzyme B in the intestinal tract. Thus, thermophile-fermented compost could contain microbes or substances that activate the rat's gut mucosal immune response. (C) 2012, The Society for Biotechnology, Japan. All rights reserved.
  • Hirokuni Miyamoto, Hiroaki Kodama, Motoaki Udagawa, Kenichi Mori, Jiro Matsumoto, Hatsumi Oosaki, Tatsuo Oosaki, Masayuki Ishizeki, Daisuke Ishizeki, Ryusuke Tanaka, Teruo Matsushita, Yuriko Kurihara, Hisashi Miyamoto
    RESEARCH IN VETERINARY SCIENCE 93(1) 137-142 2012年8月  査読有り
    Food produced via fermentation with mesophilic bacteria has been used to confer health benefits. In contrast, mammalian physiological responses to the intake of thermophile-fermented products have not been thoroughly investigated. We examined the effects of administering a compost extract consisting of fermented marine animals with thermophiles, including Bacillaceae, to pregnant sows and piglets. Retrospective studies were performed on two different swine farms (n = 330-1050 sows). The rate of stillbirth was markedly lower in all parities of the compost extract-fed group compared to those of the control group (p &lt;= 0.001). Additionally, the birth to weaning period of newborns was significantly shorter (p &lt; 0.0001), while the ratio of weanlings per liveborn piglets was increased by more than 6.5% in the compost extract-fed group. Thus thermophiles and their products in the compost extract might promote growth and reduce stillbirths of piglets during the birth to weaning period. (C) 2011 Elsevier Ltd. All rights reserved.
  • Kiyoshi Matsubara, Satoko Kei, Mayuko Koizumi, Hiroaki Kodama, Toshio Ando
    JOURNAL OF PLANT PHYSIOLOGY 169(9) 920-923 2012年6月  査読有り
    Modern commercial petunias exhibit a wide range of flower colors, which can be observed in gardens. In this study, we present a petunia cultivar that exhibits a floral pattern that is invisible to humans but is possibly visible to pollinating insects. We show that this hidden pattern is established by differentially localized accumulation of flavonols and cinnamic acid derivatives in the corolla limb. This accumulation is caused by a combination of two distinct mechanisms that inhibit anthocyanin biosynthesis: a loss-of-function mutation in the ANTHOCYANIN2, and localized RNA-silencing of CHALCONE SYNTHASE-A. (C) 2012 Elsevier GmbH. All rights reserved.
  • Yoshio Kawaguchi, Takumi Nishiuchi, Hiroaki Kodama, Toshitsugu Nakano, Kazuma Nishimura, Katsuyoshi Shimamura, Kazuo Yamaguchi, Kazuyuki Kuchitsu, Hideaki Shinshi, Kaoru Suzuki
    PLANT GROWTH REGULATION 66(1) 59-68 2012年1月  査読有り
    In this study, we investigated responses of growing and intact tobacco (N. tabacum cv Xanthi) seedlings to a fungal elicitor, a xylanase from Trichoderma viride (TvX). In addition to the induction of defense gene expression, TvX treatment caused the retardation of growth of seedlings. In the TvX-treated seedlings, growth of primary roots was markedly reduced through repression of cell division and longitudinal cell elongation in a meristematic zone and an elongation zone, respectively. However, cell differentiation to form vascular bundles and root hairs continued. In the TvX-treated root cap, disappearance of starch granules in columella cells and aggregation of border cells were observed. Furthermore, the TvX-induced growth retardation was restored after removal of the elicitor, resulting in a plastic alteration of root architecture. Therefore, the fungal elicitor might act as an environmental cue that regulates root growth and development as well as the ordinary defense responses in plant seedlings. These findings suggest a novel aspect of plant growth regulation via a plant-microbe interaction in the rhizosphere.
  • Kenichi Mori, Toshiyuki Ito, Hirokuni Miyamoto, Masayo Ozawa, Shinji Wada, Yoshifumi Kumagai, Jiro Matsumoto, Rie Naito, Shogo Nakamura, Hiroaki Kodama, Yuriko Kurihara
    JOURNAL OF BIOSCIENCE AND BIOENGINEERING 112(2) 145-150 2011年8月  査読有り
    The timings of the administration of microbial supplements to control the populations of gut microbiota of piglets have been poorly understood. Here the effects of temporal administering multispecies microbial supplements to sows on the composition of gut microbiota and on the bacteria-mediated fecal metabolites in their offsprings were investigated. During gestation and lactation, pregnant sows were fed either a normal diet (group A) or a diet with multispecies supplements comprised of nine microbial species such as Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium bifidum, Enterococcus faecium, Candida pintolopesii, and Aspergillus oryzae etc. (group B). All of the sows&apos; piglets were temporarily fed with the same supplements around weaning in accordance with the guideline of the farm. This regimen was followed by a normal diet in both groups over one month thereafter. Under such conditions, the concentration of short-chain fatty acids (SCFAs) in fecal samples remarkably increased in group B compared to group A. When 16S rDNA sequences of the fecal bacteria were analyzed, the microbial structure of bacteria was different between both goups. Especially the Clostridium cluster IV and subcluster XIVa were particularly increased in group B, although the administered microbes were undetectable. Thus, temporal administration of multispecies-microbial supplements to pregnant sows changes the composition of SCFAs and gut microbiota in their offsprings. (C) 2011, The Society for Biotechnology, Japan. All rights reserved.
  • Satoko Hasegawa, Yusuke Sogabe, Tomoya Asano, Tomoyuki Nakagawa, Haruna Nakamura, Hiroaki Kodama, Hiroyuki Ohta, Kazuo Yamaguchi, Martin J. Mueller, Takumi Nishiuchi
    PLANT CELL AND ENVIRONMENT 34(5) 705-716 2011年5月  査読有り
    Root-to-shoot communication plays an important role in the adaptation to environmental stress. In this study, we established a model system for root-to-shoot signalling to observe global gene expression in Arabidopsis thaliana. The roots of Arabidopsis seedlings were wounded and the expression in the shoots of 68 and 5 genes was up-regulated threefold at 30 min and 6 h post-injury, respectively. These genes were designated early and late Root-to-Shoot responsive (RtS) genes, respectively. Many of the early RtS genes were found to encode transcription factors such as AtERFs, whereas others were associated with jasmonic acid (JA) and ethylene (ET). Some of the late RtS genes were shown to be regulated by 12-oxo-phytodienoic acid (OPDA). In fact, elevated levels of JA and OPDA were detected in the shoots of seedlings 30 min and 6 h, respectively, after wounding of the roots. A mutant analysis revealed that JA and ET are involved in the expression of the early RtS genes. Thus, root-to-shoot communication for many RtS genes is associated with the systemic production of JA, OPDA and possibly ET.
  • Yusuke Sogabe, Haruna Nakamura, Tomoyuki Nakagawa, Satoko Hasegawa, Tomoya Asano, Hiroyuki Ohta, Kazuo Yamaguchi, Martin J. Mueller, Hiroaki Kodama, Takumi Nishiuchi
    Plant Signaling and Behavior 6(7) 119-121 2011年  査読有り
    It is known that wounding systemically activates the expression of various defense-related genes in plants. However, most studies of wound-induced systemic response are concerned with a leaf-toleaf response. We have recently reported that the long distance signaling was also observed in the shoots of Arabidopsis seedling with wounded roots. We identified early and late root-to-shoot responsive (RtS) genes that were upregulated in the shoots of root-wounded seedlings at 30 min and 6 h post-injury, respectively. It is likely that the primary signals were rapidly transfered from injured roots to shoots, and then these signals were converted into chemical signals. In fact, increase of JA and OPDA content activated the expression of early and late RtS genes in shoots, respectively. In addition, we visualized wound-induced root-to-shoot response by using RtS promoter- luciferase (Luc) transgenic plants. Analysis of the AtERF13 promoter::Luc transgenic plants clearly shows that the wound-induced root-to-shoot signaling was rapidly activated via the vascular systems. © 2011 Landes Bioscience.
  • Takeshi Ishimizu, Hiroaki Kodama, Toshio Ando, Masao Watanabe
    GENES & GENETIC SYSTEMS 85(4) 259-263 2010年8月  査読有り
    After landing on the stigma, the pollen grain germinates and elongates a tube to deliver its generative nuclei to the egg cell of the ovule. The molecular mechanisms involved in the drastic morphological changes in the pollen grain during this fertilization process remain largely unknown. In this study, the expression of 732 randomly selected genes in petunia pollen and pollen tubes was analyzed by microarray and quantitative PCR analyses. We found no evidence for up-regulation of any of these genes in the pollen tube. Our findings provide support at the gene level for the longstanding hypothesis that pollen germination and tube growth are not dependent on new RNA synthesis and that the large number of RNAs., required for germination and tube growth are stored in mature pollen grains.
  • Shin-ichiro Oka, Kaoru Midorikawa, Hiroaki Kodama
    PLANT BIOTECHNOLOGY REPORTS 4(3) 185-192 2010年7月  査読有り
    The Arabidopsis omega-3 fatty acid desaturase (AtFAD7) catalyzes the synthesis of trienoic fatty acids (TA). A transgenic tobacco line, T15, was produced by a sense AtFAD7 construct and showed a cosuppression-like phenotype, namely extremely low TA levels. The sequence similarity between AtFAD7 and a tobacco ortholog gene, NtFAD7, was moderate (about 69%) in the coding sequences. AtFAD7 siRNAs accumulated at a high level, and both AtFAD7 and NtFAD7 mRNAs are degraded in T15 plants. The low-TA phenotype in T15 was dependent on a tobacco RNA-dependent RNA polymerase6 (NtRDR6). We also produced tobacco RNAi plants targeting AtFAD7 gene sequences. The AtFAD7 siRNA level was trace, which was associated with a slight reduction in leaf TA level. Unexpectedly, this RNAi plant showed an increased NtFAD7 transcript level. To investigate the effect of translational inhibition on stability of the NtFAD7 mRNAs, leaves of the wild-type tobacco plants were treated with a translational inhibitor, cycloheximide. The level of NtFAD7 mRNAs significantly increased after cycloheximde treatment. These results suggest that the translational inhibition by low levels of AtFAD7 siRNAs or by cycloheximide increased stability of NtFAD7 mRNA. The degree of silencing by an RNAi construct targeting the AtFAD7 gene was increased by co-existence of the AtFAD7 transgene, where NtRDR6-dependent amplification of siRNAs occurred. These results indicate that NtRDR6 can emphasize silencing effects in both cosuppression and RNAi.
  • Sayaka Hirai, Kouta Takahashi, Tomomi Abiko, Hiroaki Kodama
    FEBS JOURNAL 277(7) 1695-1703 2010年4月  査読有り
    RNA silencing is an epigenetic inhibition of gene expression and is guided by small interfering RNAs. Sense transgene-induced post-transcriptional gene silencing (S-PTGS) occurs in a portion of a transgenic plant population. When a sense transgene encoding a tobacco endoplasmic reticulum omega-3 fatty acid desaturase (NtFAD3) was introduced into tobacco plants, an S-PTGS line, S44, was obtained. Introduction of another copy of the NtFAD3 transgene into S44 plants caused a phenotypic change from S-PTGS to overexpression. Because this change was associated with the methylation of the promoter sequences of the transgene, reduced transcriptional activity may abolish S-PTGS and residual transcription of the sense transgene may account for the overexpression. To clarify whether RNA-directed DNA methylation (RdDM) can repress the transcriptional activity of the S44 transgene locus, we introduced several RdDM constructs targeting the transgene promoter. An RdDM construct harboring a 200-bp-long fragment of promoter sequences efficiently abrogated the generation of NtFAD3 small interfering RNAs in S44 plants. Transcription of the transgene was partially repressed, but the resulting NtFAD3 mRNAs successfully accumulated and an overexpressed phenotype was established. Our results indicate an example in which overexpression of the transgene is established by complex epigenetic interactions among the transgenic loci.
  • Ryusuke Tanaka, Hirokuni Miyamoto, Hiroaki Kodama, Nobuhiro Kawachi, Motoaki Udagawa, Hisashi Miyamoto, Teruo Matsushita
    JOURNAL OF GENERAL AND APPLIED MICROBIOLOGY 56(1) 61-65 2010年2月  査読有り
  • Kazuma Nishimura, Sayaka Hirai, Hiroaki Kodama
    JOURNAL OF BIOSCIENCE AND BIOENGINEERING 108(5) 435-437 2009年11月  査読有り
    Small interfering RNAs (siRNAs) generated from the spacer region of hairpin RNAs were not detected in the RNA interference (RNAi) plants targeting the fatty acid desaturase gene. The expression of the desaturase gene was stably suppressed even when siRNAs targeting the spacer sequences were introduced into this plant. (C) 2009, The Society for Biotechnology, Japan. All rights reserved.

MISC

 87
  • Hirokuni Miyamoto, Katsumi Shigeta, Wataru Suda, Yasunori Ichihashi, Naoto Nihei, Makiko Matsuura, Arisa Tsuboi, Naoki Tominaga, Masahiko Aono, Muneo Sato, Shunya Taguchi, Teruno Nakaguma, Naoko Tsuji, Chitose Ishii, Teruo Matsushita, Chie Shindo, Toshiaki Ito, Tamotsu Kato, Hiroshi Ohno, Atsushi Kurotani, Hideaki Shima, Shigeharu Moriya, Sankichi Horiuchi, Kenichi Mori, Hisashi Miyamoto, Masahira Hattori, Hiroaki Kodama, Jun Kikuchi, Yumi Hirai
    2022年2月7日  
    Compost is used worldwide as a soil conditioner for crops, but its functions remain unclear. Here, the omics profiles of carrots and soil amended with compost fermented by thermophilic Bacillaceae, as a compost model, are classified based on information on carrots' growth, color, and taste characteristics. The production of carrots and their antioxidant activity were significantly increased by compost exposure, as was their content of carotenes, essential carrot nutrients. Furthermore, omics profiles revealed that carrots' growth, red color, and taste could be increased by altering characteristic leaf, root, and soil metabolites by compost exposure. In particular, structural equation modeling statistically predicted a strong association with nitrogen-cycle related-soil bacteria candidates, which could modulate nitrogen fixation and anaerobic ammonium oxidation (anammox), affected by compost. These observations statistically provide a novel perspective on potential sustainable compost as an organic fertilizer that has the role of preserving the environment.
  • SHI SHUQI, 西田彩夏, 梶原悠, 井藤俊行, 渡邊健吾, 須田栞, 土肥博史, 宮本浩邦, 宮本浩邦, 宮本浩邦, 児玉浩明
    日本農芸化学会大会講演要旨集(Web) 2021 2021年  
  • 宮原平, 梅山幸子, 辻本恭, 小関良宏, 小川拓水, 山口夕, 太田大策, 小口太一, 児玉浩明
    日本食品化学学会総会・学術大会講演要旨集 26th 2020年  
  • 小川拓水, 山口夕, 小口太一, 宮原平, 辻本恭, 小関良宏, 児玉浩明, 太田大策
    日本食品化学学会総会・学術大会講演要旨集 26th 2020年  
  • 梅山幸子, 宮原平, 小口太一, 太田大策, 辻本恭, 小関良宏, 児玉浩明
    日本農芸化学会大会講演要旨集(Web) 2020 2020年  

講演・口頭発表等

 205

担当経験のある科目(授業)

 23

共同研究・競争的資金等の研究課題

 31

産業財産権

 12