Directory of Researchers

AZUMA Tetsushi
Graduate School of Agricultural Science / Department of Bioresource Science
Professor
Agriculture
Last Updated :2024/02/09

Researcher Profile and Settings

Affiliation

  • <Faculty / Graduate School / Others>

    Graduate School of Agricultural Science / Department of Bioresource Science
  • <Related Faculty / Graduate School / Others>

    Faculty of Agriculture / Department of Bioresource Science

Teaching

Research Activities

Research Areas

  • Environmental science/Agricultural science / Crop production science

Published Papers

  • Akina Mizumoto, Masahiko Tanio, Kou Nakazono, Kazuhiro Watanabe, Akira Uchino, Tetsushi Azuma

    Last, Informa UK Limited, 03 Sep. 2023, Plant Production Science, 1 - 9

    [Refereed]

    Scientific journal

  • Quanshu Luo, Daisuke Sasayama, Misaki Nakazawa, Tomoko Hatanaka, Hiroshi Fukayama, Tetsushi Azuma

    Informa UK Limited, 01 Jan. 2023, Plant Production Science, 26 (1), 1 - 11

    [Refereed]

    Scientific journal

  • Akina Mizumoto, Masahiko Tanio, Kazuhiro Watanabe, Kou Nakazono, Akira Uchino, Tetsushi Azuma

    Frost injury is a concern in early-sown spring wheat (Triticum aestivum) in the Tokai region of Japan. To assess the efficacy of ground rolling as a technique for avoiding frost injury, we investigated its effects on the apical development and yield of 'Ayahikari' spring wheat. In both 2018-19 and 2019-20, rolling delayed spikelet initiation by 4-5 days, the start of internode elongation by 5-12 days, and jointing by 3-9 days, but did not affect the apical development rate, which depended on the thermal time. Ground rolling prevented frost injury in 2018-19 but not in 2019-20, probably because the warmer-than-average winter promoted earlier jointing, and so plants were exposed to later low temperatures in February. These results suggest that ground rolling is an effective method for avoiding frost injury in spring wheat during cold winters.

    Last, TAYLOR & FRANCIS LTD, Oct. 2022, PLANT PRODUCTION SCIENCE, 25 (4), 434 - 439, English

    [Refereed]

    Scientific journal

  • Daisuke Sasayama, Mayuko Niikawa, Tomoko Hatanaka, Hiroshi Fukayama, Tetsushi Azuma

    Informa UK Limited, 03 Jul. 2022, Plant Production Science, 25 (3), 350 - 358

    [Refereed]

    Scientific journal

  • Kako Matsumoto, Daisuke Sasayama, Tomoko Hatanaka, Hiroshi Fukayama, Tetsushi Azuma

    Jul. 2022, Journal of Crop Research, 67, 51 - 55

    [Refereed]

  • Daisuke Sasayama, Shangmin Yuan, Tomoko Hatanaka, Hiroshi Fukayama, Tetsushi Azuma

    Jul. 2022, Journal of Crop Research, 67, 35 - 40

    [Refereed]

  • Tomoko Hatanaka, Yoshiki Tomita, Daisuke Matsuoka, Daisuke Sasayama, Hiroshi Fukayama, Tetsushi Azuma, Mohammad Fazel Soltani Gishini, David Hildebrand

    Abstract Triacylglycerols (TAGs) are the major component of plant storage lipids such as oils. Acyl-CoA:diacylglycerol acyltransferase (DGAT) catalyzes the final step of the Kennedy pathway, and is mainly responsible for plant oil accumulation. We previously found that the activity of Vernonia DGAT1 was distinctively higher than that of Arabidopsis and soybean DGAT1 in a yeast microsome assay. In this study, the DGAT1 cDNAs of Arabidopsis, Vernonia, soybean, and castor bean were introduced into Arabidopsis. All Vernonia DGAT1-expressing lines showed a significantly higher oil content (49% mean increase compared with the wild-type) followed by soybean and castor bean. Most Arabidopsis DGAT1-overexpressing lines did not show a significant increase. In addition to these four DGAT1 genes, sunflower, Jatropha, and sesame DGAT1 genes were introduced into a TAG biosynthesis-defective yeast mutant. In the yeast expression culture, DGAT1s from Arabidopsis, castor bean, and soybean only slightly increased the TAG content; however, DGAT1s from Vernonia, sunflower, Jatropha, and sesame increased TAG content >10-fold more than the former three DGAT1s. Three amino acid residues were characteristically common in the latter four DGAT1s. Using soybean DGAT1, these amino acid substitutions were created by site-directed mutagenesis and substantially increased the TAG content.

    Oxford University Press (OUP), 04 Mar. 2022, Journal of Experimental Botany, 73 (9), 3030 - 3043

    [Refereed]

    Scientific journal

  • Hiroshi Fukayama, Fumihiro Miyagawa, Naoki Shibatani, Aiko Koudou, Daisuke Sasayama, Tomoko Hatanaka, Tetsushi Azuma, Yasuo Yamauchi, Daisuke Matsuoka, Ryutaro Morita

    CO2-responsive CCT protein (CRCT) is a positive regulator of starch synthesis-related genes such as ADP-glucose pyrophosphorylase large subunit 1 and starch branching enzyme I particularly in the leaf sheath of rice (Oryza sativa L.). The promoter GUS analysis revealed that CRCT expressed exclusively in the vascular bundle, whereas starch synthesis-related genes were expressed in different sites such as mesophyll cell and starch storage parenchyma cell. However, the chromatin immunoprecipitation (ChIP) using a FLAG-CRCT overexpression line and subsequent qPCR analyses showed that the 5 '-flanking regions of these starch synthesis-related genes tended to be enriched by ChIP, suggesting that CRCT can bind to the promoter regions of these genes. The monomer of CRCT is 34.2 kDa; however, CRCT was detected at 270 kDa via gel filtration chromatography, suggesting that CRCT forms a complex in vivo. Immunoprecipitation and subsequent MS analysis pulled down several 14-3-3-like proteins. A yeast two-hybrid analysis and bimolecular fluorescence complementation assays confirmed the interaction between CRCT and 14-3-3-like proteins. Although there is an inconsistency in the place of expression, this study provides important findings regarding the molecular function of CRCT to control the expression of key starch synthesis-related genes.

    WILEY, Aug. 2021, PLANT CELL AND ENVIRONMENT, 44 (8), 2480 - 2493, English

    [Refereed]

    Scientific journal

  • Shunsuke Oe, Daisuke Sasayama, Quanshu Luo, Hiroshi Fukayama, Tomoko Hatanaka, Tetsushi Azuma

    We screened 80 Asian rice (Oryza sativa L.) cultivars for the presence of the submergence-tolerance gene SUB1A-1 and the floating genes SNORKEL1 (SK1) and SNORKEL2 (SK2), and found that the deepwater rice cultivar Baisbish (BSB) and the submergence-tolerant cultivar Flood Resistant 13A (FR13A) both possess the SUB1A-1 and the SK1/2. When BSB and FR13A seedlings were completely submerged, spindly growth of shoots was induced in BSB but not in FR13A. Submergence significantly increased the SUB1A-1 transcript abundance in BSB and FR13A shoots, but the expression level in BSB was much lower than that of FR13A. Submergence also induced the expression of both ERF66 and ERF67, the transcriptional targets of SUB1A-1, in FR13A shoots, whereas it upregulated the expression of ERF67 but not that of ERF66 in BSB shoots. These results suggest that BSB could not display submergence tolerance due to the low expression of SUB1A-1 and/or ERF66 under submergence.

    TAYLOR & FRANCIS LTD, Jul. 2021, PLANT PRODUCTION SCIENCE, English

    [Refereed]

    Scientific journal

  • Quanshu Luo, Misaki Nakazawa, Daisuke Sasayama, Hiroshi Fukayama, Tomoko Hatanaka, Tetsushi Azuma

    Jun. 2020, Journal of Crop Research, 65, 37 - 41

    [Refereed]

  • Hideo Hamaguchi, Akinori Takeda, Toshio Sugimoto, Tetsushi Azuma

    Last, Jun. 2020, Journal of Crop Research, 65, 23 - 29

    [Refereed]

  • Hideo Hamaguchi, Naoki Yamamoto, Akinori Takeda, Takehiro Masumura, Toshio Sugimoto, Tetsushi Azuma

    Last, Informa UK Limited, 04 Dec. 2019, Soil Science and Plant Nutrition, 66 (2), 299 - 307

    [Refereed]

    Scientific journal

  • Hiroshi Fukayama, Akina Mizumoto, Chiaki Ueguchi, Jun Katsunuma, Ryutaro Morita, Daisuke Sasayama, Tomoko Hatanaka, Tetsushi Azuma

    The relationship between ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase (Rca) levels was studied using transgenic rice overexpressing maize Rca (OX-mRca) and knockdown transgenic rice expressing antisense Rca (KD-Rca). The ratio of Rubisco to total soluble protein was lower in OX-mRca, whereas it was higher in KD-Rca than in WT, indicating that Rca expression was negatively correlated with Rubisco content. The expressions of other Calvin–Benson–Bassham cycle enzymes such as sedoheptulose-1,7-bisphosphatase and phosphoribulokinase analyzed by immunoblotting did not show such a negative correlation with Rca, suggesting that the effect of Rca on protein expression may be specific for Rubisco. Although Rubisco content was decreased in OX-mRca, the transcript levels of the Rubisco large subunit (OsRbcL) and the Rubisco small subunit mostly increased in OX-mRca as well as in KD-Rca. Additionally, polysome loading of OsRbcL was slightly higher in OX-mRca than it was in WT, suggesting that the OsRbcL translation activity was likely stimulated by overexpression of Rca. 35S-methionine labeling experiments demonstrated that there was no significant difference in the stability of newly synthesized Rubisco among genotypes. However, 35S-methionine-labeled Rubisco was marginally decreased in OX-mRca and increased in KD-Rca compared to the WT. These results suggest that Rca negatively affects the Rubisco content, possibly in the synthesis step.

    Springer Netherlands, 30 May 2018, Photosynthesis Research, 1 - 10, English

    [Refereed]

    Scientific journal

  • Daisuke Sasayama, Takuma Okishio, Tatsuya Hirano, Hiroshi Fukayama, Tomoko Hatanaka, Masahiro Akimoto, Tetsushi Azuma

    Springer Science and Business Media LLC, Feb. 2018, Plant Growth Regulation, 85 (1), 123 - 132, English

    [Refereed]

    Scientific journal

  • Rubisco small subunits of C4 plants, Napier grass and guinea grass confer C4-like catalytic properties on Rubisco in rice.

    FUKAYAMA HIROSHI, 小原 崇, 塩見 慶太, 森田 隆太郎, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI

    Last, 2018, Plant Production Science, DOI: 10.1080/1343943X.2018.154, English

    [Refereed]

    Scientific journal

  • Endo Hiroaki, Niikawa Mayuko, Sasayama Daisuke, Hatanaka Tomoko, Fukayama Hiroshi, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2017, Abstracts of Meeting of the CSSJ, 244, 124 - 124, Japanese

  • Tomita Kazuyoshi, Sasayama Daisuke, Fukayama Hiroshi, Hatanaka Tomoko, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2017, Abstracts of Meeting of the CSSJ, 244, 123 - 123, Japanese

  • Hatanaka Tomoko, Tomita Yoshiki, Chau Choi-Wing, Sasayama Daisuke, Fukayama Hiroshi, Azuma Tetsushi, Hildebrand David

    CROP SCIENCE SOCIETY OF JAPAN, 2017, Abstracts of Meeting of the CSSJ, 244, 119 - 119, Japanese

  • Oe Shunsuke, Sasayama Daisuke, Fukayama Hiroshi, Hatanaka Tomoko, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2017, Abstracts of Meeting of the CSSJ, 244, 122 - 122, Japanese

  • Daisuke Sasayama, Kenta Ikemachi, Hisateru Sakai, Hiroshi Fukayama, Kazuyuki Itoh, Tetsushi Azuma

    The semiaquatic plants, Sagittaria trifolia and Sagittaria pygmaea, are perennial and troublesome weeds of rice paddy fields. These species mainly reproduce vegetatively via tubers, which sprout after the rice paddy fields are irrigated. Sprouting finally leads to the emergence of the shoots from the water in the paddy fields. In both species, the first internode elongates around the time of emergence and this lifts the shoot meristems in the soil, aiding in the establishment of the young plants. Therefore, elongation of the internode is a factor that determines the weed damage to rice caused by these species. In this study, the first internode elongation of both species was characterized. During emergence, S. trifolia and S. pygmaea showed distinct growth patterns. In S. trifolia, the internodes elongated before the emergence of the shoots from the water; whereas, in S. pygmaea, the internodes started to elongate only after emergence. We examined environmental prerequisites for internode elongation, and found that the internode elongation of S. trifolia was induced by submergence and was independent of the soil cover, while that of S. pygmaea required both submergence and covering. Next, we determined which gaseous factors were responsible for internode elongation. Treatment with ethylene, which enhances growth of several other aquatic and semiaquatic plants, did not stimulate internode elongation in either species under an anaerobic condition. Our results suggested that the gaseous factor stimulating internode elongation in S. trifolia and S. pygmaea may be oxygen depletion and carbon dioxide, respectively.

    WILEY-BLACKWELL, Dec. 2016, WEED BIOLOGY AND MANAGEMENT, 16 (4), 147 - 156, English

    [Refereed]

    Scientific journal

  • Katsuya Tamada, Kazuyuki Itoh, Yuko Uchida, Shunsuke Higuchi, Daisuke Sasayama, Tetsushi Azuma

    The successful overwintering of water lettuce (Araceae, Pistia stratiotes L.) is reported in Kowataike, a pond in Kyoto Prefecture, Japan, in the temperate climate zone. Overwintering was observed in the northern zone of Kowataike, where warm water discharge flows from an upstream electrical appliance factory. From December 2007 to January 2008, several overwintering water lettuce plants were observed in the northern zone where the water temperature was abnormally high (average: 21.9 degrees C; low: 19.5 degrees C). Water in the central zone of Kowataike was isolated from the warm water discharge. The temperatures here were much lower (average: 8.2 degrees C; low: 4.2 degrees C) and no water lettuce plant survived here. The overwintering in the northern zone fluctuated annually. This fluctuation appeared to be correlated with the period of warm water discharge, which varied from year to year and resulted in higher water temperatures most, but not all, of the winter. The results suggest that artificial environmental factors, such as anthropogenic warm water discharge, could enable water lettuce to overwinter. In the northern zone of Kowataike under the influence of the warm water discharge, only small water lettuce plants overwintered. This may be attributed to the presence of older plants with larger leaves that seemed to protect the small rosettes from frost. Second, the air warmed by the warm discharge accumulated in the space under the piles of dead large leaves, which created conditions similar to those of a greenhouse. These two mechanisms apparently allow the small water lettuce plants to be surrounded by moderate atmospheric conditions.

    Last, WILEY-BLACKWELL, Mar. 2015, WEED BIOLOGY AND MANAGEMENT, 15 (1), 20 - 26, English

    [Refereed]

    Scientific journal

  • Takuma Okishio, Daisuke Sasayama, Tatsuya Hirano, Masahiro Akimoto, Kazuyuki Itoh, Tetsushi Azuma

    The Amazonian wild rice Oryza grandiglumis has two contrasting adaptation mechanisms to flooding submergence: a quiescence response to complete submergence at the seedling stage and an escape response based on internodal elongation to partial submergence at the mature stage. We investigated possible factors that trigger these responses. In stem segments excised from mature O. grandiglumis plants, complete submergence only slightly promoted internodal elongation with increased ethylene levels in the internodes, while partial submergence substantially promoted internodal elongation without increased ethylene levels in the internodes. Incubation of non-submerged stem segments under a continuous flow of humidified ethylene-free air promoted internodal elongation to the same extent as that observed for partially submerged segments. Applied ethylene had little effect on the internodal elongation of non-submerged segments irrespective of humidity conditions. These results indicate that the enhanced internodal elongation of submerged O. grandiglumis plants is not triggered by ethylene accumulated during submergence but by the moist surroundings provided by submergence. The growth of shoots in O. grandiglumis seedlings was not promoted by ethylene or complete submergence, as is the case in O. sativa cultivars possessing the submergence-tolerant gene SUB1A. However, because the genome of O. grandiglumis lacks the SUB1A gene, the quiescence response of O. grandiglumis seedlings to complete submergence may be regulated by a mechanism distinct from that involved in the response of submergence-tolerant O. sativa cultivars. (C) 2014 Elsevier GmbH. All rights reserved.

    ELSEVIER GMBH, URBAN & FISCHER VERLAG, Feb. 2015, JOURNAL OF PLANT PHYSIOLOGY, 174, 49 - 54, English

    [Refereed]

    Scientific journal

  • Hirai Yuki, Sasayama Daisuke, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2015, Abstracts of Meeting of the CSSJ, 240, 84 - 84, Japanese

  • Iwami Yuta, Sasayama Daisuke, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2015, Abstracts of Meeting of the CSSJ, 240, 28 - 28, Japanese

  • Sasayama Daisuke, Hirai Yuki, Azuma Tetsushi

    CROP SCIENCE SOCIETY OF JAPAN, 2015, Abstracts of Meeting of the CSSJ, 240, 30 - 30, Japanese

  • Takuma Okishio, Daisuke Sasayama, Tatsuya Hirano, Masahiro Akimoto, Kazuyuki Itoh, Tetsushi Azuma

    In Asian cultivated rice (Oryza sativa), distinct mechanisms to survive flooding are activated in two groups of varieties. Submergence-tolerant rice varieties possessing the SUBMERGENCE1A (SUB1A) gene display reduced growth during flash floods at the seedling stage and resume growth after the flood recedes, whereas deepwater rice varieties possessing the SNORKEL1 (SK1) and SNORKEL2 (SK2) genes display enhanced growth based on internodal elongation during prolonged submergence at the mature stage. In this study, we investigated the occurrence of these growth responses to submergence in the wild rice species Oryza grandiglumis, which is native to the Amazon floodplains. When subjected to gradual submergence, adult plants of O. grandiglumis accessions showed enhanced internodal elongation with rising water level and their growth response closely resembled that of deepwater varieties of O. sativa with high floating capacity. On the other hand, when subjected to complete submergence, seedlings of O. grandiglumis accessions displayed reduced shoot growth and resumed normal growth after desubmergence, similar to the response of submergence-tolerant varieties of O. sativa. Neither SUB1A nor the SK genes were detected in the O. grandiglumis accessions. These results indicate that the O. grandiglumis accessions are capable of adapting successfully to flooding by activating two contrasting mechanisms as the situation demands and that each mechanism of adaptation to flooding is not mediated by SUB1A or the SK genes.

    SPRINGER, Sep. 2014, PLANTA, 240 (3), 459 - 469, English

    [Refereed]

    Scientific journal

  • Tetsushi Azuma, Yoshitaka Inoue, Yuma Hamada, Takuma Okishio, Daisuke Sasayama, Kazuyuki Itoh

    Gravitropic curvature of pulvini of wheat and oat stem segments gradually declined with decreasing atmospheric O-2 concentration and was almost completely blocked under anoxia, whereas that of rice stem segments was enhanced under hypoxia and anoxia. Anoxia substantially increased the ethanol content in pulvini of gravistimulated stem segments in rice, wheat and oat, but the ethanol content showed no marked difference between rice pulvini and wheat and oat pulvini. The concentrations of exogenous ethanol and acetaldehyde required to inhibit the gravitropic curvature of pulvini were significantly higher in rice segments than in wheat and oat segments. However, in all three species, the concentrations of ethanol and acetaldehyde required to completely inhibit curvature were several-fold higher than the endogenous levels that accumulated in pulvini gravistimulated in N-2. The pulvini of rice segments gravistimulated in N-2 did not contain much more ATP than those of wheat or oat segments gravistimulated in N-2. When applied unilaterally to the pulvini of vertically oriented stem segments incubated in N-2, indole-3-acetic acid induced bending. in rice stem segments but not in wheat and oat stem segments. Transference of graviresponsive pulvini of rice, as well as those of wheat and oat, from aerobic conditions to anaerobic conditions led to cessation of gravitropic curvature within several minutes, but subsequently only gravitropic curvature of anoxic rice pulvini was completely recovered within 2 h. A large portion of this recovery was blocked by cordycepin, a transcription inhibitor. These results' suggested that anoxia-induced expression of any gene or genes enables rice pulvini to respond to gravistimulation under anaerobic conditions, and that such a gene or genes might be unrelated to ethanol fermentation and ATP production in anaerobic conditions. (C) 2013 Elsevier GmbH. All rights reserved.

    ELSEVIER GMBH, URBAN & FISCHER VERLAG, Sep. 2013, JOURNAL OF PLANT PHYSIOLOGY, 170 (13), 1158 - 1164, English

    [Refereed]

    Scientific journal

  • Striga infestation in Kenya: Status, distribution and management options

    Atera AE, Ishii T, Onyango JC, Itoh K, Azuma T

    Last, 2013, Sust Agr Res, 2, 99 - 108, English

    [Refereed]

    Scientific journal

  • Evans Atuti Atera, Kazuyuki Itoh, Tetsushi Azuma, Takashige Ishii

    Witchweed, Striga hermonthica (hereafter, referred to as Striga), is a major biotic constraint to cereal production in sub-Saharan Africa. The parasitic plant is a socioeconomic problem that has forced some resource-poor farmers to abandon their farms due to high infestation. This study was designed in order to elucidate farmers' perceptions of Striga control measures and to determine their potential adoption in two villages in western Kenya. Participatory rural appraisals and individual interviews were conducted in 2009 and 2010 in a sample of 128 and 120 households in Kaura and Kogweno-Oriang villages in Homabay and Rachuonyo districts, respectively. The results revealed that crop production was the main occupation in most households. The farmers identified Striga as one of the major constraints to maize, sorghum, and finger millet production. According to the farmers, the most popular control measures were hand-pulling, crop rotation, and intercropping, even though rotational systems might need a longer timeframe to reduce the soil seed bank of Striga. Although the level of Striga infestation and damage were increasing in the farmers' fields, the adoption of the control options was limited. The reason for the low adoption level of the control methods by the farmers is because they are too risky as there is no guarantee of a direct pay-off in increased crop yield. Farmer-led evaluation and adaptation of the various Striga control technologies in real-life situations will facilitate the choice of appropriate options and facilitate their uptake.

    WILEY-BLACKWELL, Mar. 2012, WEED BIOLOGY AND MANAGEMENT, 12 (1), 53 - 62, English

    [Refereed]

    Scientific journal

  • Hamada Yuma, Azuma Tetsushi, Itoh Kazuyuki

    CROP SCIENCE SOCIETY OF JAPAN, 2012, Abstracts of Meeting of the CSSJ, 234, 308 - 308, Japanese

  • Response of NERICA Rice to Striga hermonthica Infections in Western Kenya

    Evans A. Atera, Kazuyuki Itoh, Tetsushi Azuma, Takashige Ishii

    Striga hermonthica (Del.) Benth (hereafter referred to as Striga), an obligate root hemiparasite, poses a serious threat to cereal production in sub-Saharan Africa. Field experiments were conducted in two years at Alupe farm, western Kenya, to investigate the effect of Striga on growth and yield parameters of New Rice for Africa (NERICA) cultivars. A randomized complete block design replicated three times and rice cultivars NERICA 1, NERICA 4, NERICA 10, NERICA 11 and Dourado precoce, a local landrace were used. Striga significantly reduced grain yield and the yield components. Reduction in grain yield and its components were more severe under moisture stress period in 2008. Grain yield loss ranged between 33-90%. NERICA 1 gave the highest yield in the two seasons both in Striga infected and control plants. This was followed by NERICA 10, which was also the most economically viable when infected with Striga. Result showed that both NERICA 1 and NERICA 10 are resistant to S. hermonthica, while NERICA 4 is highly susceptible. (C) 2012 Friends Science Publishers

    FRIENDS SCIENCE PUBL, 2012, INTERNATIONAL JOURNAL OF AGRICULTURE AND BIOLOGY, 14 (2), 271 - 275, English

    [Refereed]

    Scientific journal

  • Farmers’ perception and constraints to the adoption of weed control options: the case of Striga asiatica in Malawi

    Atera AE, ITOH KAZUYUKI, AZUMA TETSUSHI, ISHII TAKASHIGE

    2012, J Agr Sci, 4, 41 - 50, English

    [Refereed]

    Scientific journal

  • Involvement of Plant Hormones in the Gravitropic Response of Floating Rice Pulvini and Effect of Submergence on the Response

    東 哲司, Yoshitaka Inoue, Chiharu Kishida, 笹山 大輔, Takuma Okishio, 伊藤 一幸

    Sep. 2011, Tropical Agriculture and Development, 55, 113 - 117, English

    [Refereed]

    Scientific journal

  • Characterization of gravitropic response of leaf-sheath pulvini in floating rice

    東 哲司, Yuko Takenaga, 笹山 大輔, Yoshitaka Inoue, Takuma Okishio, 伊藤 一幸

    Sep. 2011, Tropical Agriculture and Development, 55, 108 - 112, English

    [Refereed]

    Scientific journal

  • Daisuke Sasayama, Tetsushi Azuma, Kazuyuki Itoh

    The cell walls in the elongating zone of submerged floating rice internodes show high susceptibility to expansins. When internode sections corresponding to such an elongation zone were incubated for 24 h under osmotic stress conditions produced by treatment with 100 mM polyethylene glycol 4000 (PEG), the cell wall susceptibility to expansins remained at its initial level, while the susceptibility of internode sections incubated under unstressed conditions decreased considerably during the same period. The contents of polysaccharides and phenolic acids as ferulic, diferulic and p-coumaric acids in the cell walls of internode sections increased substantially under unstressed conditions, but the increases were almost completely prevented by osmotic stress. Ferulic acid applied to internode sections under osmotic stress reduced the susceptibility of the cell walls to expansins and increased the levels of ferulic and diferulic acids in the cell walls, with little effect on the accumulation of polysaccharides. In contrast, applied p-coumaric acid increased the level of p-coumaric acid in the cell walls without a change in the levels of ferulic and diferulic acids but did not reduce the susceptibility to expansins. These results suggest that the deposition of ferulic and diferulic acids is a primary determinant in regulating the reduction of the susceptibility of cell walls to expansins in floating rice internodes. (C) 2010 Elsevier GmbH. All rights reserved.

    Corresponding, ELSEVIER GMBH, URBAN & FISCHER VERLAG, Jan. 2011, JOURNAL OF PLANT PHYSIOLOGY, 168 (2), 121 - 127, English

    [Refereed]

    Scientific journal

  • Daisuke Sasayama, Daisuke Matsuoka, Mariko Oka, Nariko Shitamichi, Tomoyuki Furuya, Tetsushi Azuma, Kazuyuki Itoh, Takashi Nanmori

    MAP3K delta 4 (At4g23050) is a Raf-like mitogen-activated protein kinase kinase kinase (MAP3K) in Arabidopsis thaliana, classified as subgroup B2. The B2 subgroup MAP3Ks have a kinase domain in the C-terminus and a PAS domain in the N-terminal region. PAS domains are found in a variety of proteins and are reported to mediate protein-protein interactions and to sense environmental stimuli. However, the function of MAP3K delta 4 has not yet been determined. We generated transgenic plants constitutively expressing MAP3K delta 4 or its kinase-negative mutant (MAP3K delta 4KN) and characterized their physiological traits. The transgenic plants overexpressing MAP3K delta 4 showed earlier bolting than wildtype plants. They also showed more vigorous growth by both fresh weight and stem length. In contrast, the transgenic plants overexpressing MAP3K delta 4KN showed a highly branched phenotype; MAP3K delta 4 overexpression had no effect on branch number. These results indicated that MAP3K delta 4 is crucial to regulating both plant growth and shoot branching. In addition, MAP3K delta 4 transcripts were found in all Arabidopsis tissues examined and upregulated by auxin treatment in seedlings, suggesting that MAP3K delta 4 functions in an auxin-dependent manner.

    JAPANESE SOC PLANT CELL & MOLECULAR BIOL, 2011, PLANT BIOTECHNOLOGY, 28 (5), 463 - 470, English

    [Refereed]

    Scientific journal

  • Daisuke Sasayama, Tetsushi Azuma, Kazuyuki Itoh

    We investigated the involvement of expansin action in determining the growth rate of internodes of floating rice (Oryza sativa L.). Floating rice stem segments in which rapid internodal elongation had been induced by submergence for 2 days were exposed to air or kept in submergence for 2 more days. Both treatments reduced the elongation rate of the internodes, and the degree of reduction was much greater in air-exposed stem segments than in continually submerged segments. These rates of internodal elongation were correlated with acid-induced cell wall extensibility and cell wall susceptibility to expansins in the cell elongation zone of the internodes, but not with extractable expansin activity. These results suggest that the reduced growth rate of internodes must be due, at least in part, to the decrease in acid-induced cell wall extensibility, which can be modulated through changes in the cell wall susceptibility to expansins rather than through expansin activity. Analysis of the cell wall composition of the internodes showed that the cellulosic and noncellulosic polysaccharide contents increased in response to exposure to air, but they remained almost constant under continued submergence although the cell wall susceptibility to expansins gradually declined even under continued submergence. The content of xylose in noncellulosic neutral sugars in the cell walls of internodes was closely and negatively correlated with changes in the susceptibility of the walls to expansins. These results suggest that the deposition of xylose-rich polysaccharides into the cell walls may be related to a decrease in acid-induced cell wall extensibility in floating rice internodes through the modulation of cell wall susceptibility to expansins.

    Corresponding, SPRINGER, Jan. 2009, PLANT GROWTH REGULATION, 57 (1), 79 - 88, English

    [Refereed]

    Scientific journal

  • Tetsushi Azuma, Takenori Honda, Ayako Sadai, Daisuke Sasayama, Kazuyuki Itoh

    We examined the effect of ethylene on the growth of rice seedlings (Oryza sativa L.) at various degrees of humidity. Ethylene significantly suppressed the growth of shoots when applied to seedlings grown under 30% relative humidity (RH), but promoted the growth of shoots when applied to seedlings grown under 100% RH. The application of gibberellic acid (GA(3)) promoted the elongation of shoots in seedlings grown under 30% and 100% RH. Ethylene inhibited the shoot elongation induced by GA(3) at 30% RH, but enhanced the elongation induced by GA(3) at 100% RH. These results indicate that ethylene can either promote or suppress the growth of rice shoots depending on ambient humidity, and that these actions of ethylene may be mediated through modulating the responsiveness of shoots to gibberellin. (C) 2007 Elsevier GmbH. All rights reserved.

    ELSEVIER GMBH, URBAN & FISCHER VERLAG, Dec. 2007, JOURNAL OF PLANT PHYSIOLOGY, 164 (12), 1683 - 1687, English

    [Refereed]

    Scientific journal

  • Involvement of acid-induced growth and expansin action in the internodal elongation of submerged floating rice

    笹山 大輔, 東 哲司, 南森 隆司, 安田 武司

    Floating or deepwater rice (Oryza sativa L.) responds to submergence by rapid internodal elongation. The involvement of acid-induced growth and the pH-dependent wall-loosening protein expansin in such internodal elongation was examined. Living internodal sections excised from floating rice stem segments that had been submerged showed significant enhancement of their growth in

    Corresponding, 日本熱帯農業学会, Sep. 2007, Japanese Journal of Tropical Agriculture, 51 (3), 95 - 101, English

    [Refereed]

    Scientific journal

  • Tory Chhun, Yuichi Uno, Shin Taketa, Tetsushi Azuma, Masahiko Ichii, Takashi Okamoto, Seiji Tsurumi

    Auxin transport plays a significant role modifying plant growth and development in response to environmental signals such as light and gravity. However, the effect of humidity on auxin transport is rarely documented. It is shown here that the transport of labelled indole-3-acetic acid (IAA) from the shoot to the root is accelerated in rice (Oryza sativa L. ssp. indica cv. IR8) seedlings grown under saturated humidity (SH-seedlings) compared with plants grown under normal humidity (NH-seedlings). The development of lateral roots in SH-seedlings was greatly enhanced compared with NH-seedlings. Removal of the shoot from SH-seedlings reduced the density of lateral roots, and the application of IAA to the cut stem restored the lateral root density, while the decapitation of NH-seedlings did not alter lateral root development. Phloem-based auxin transport appeared responsible for enhanced lateral root formation in SH-seedlings since (i) the rate of IAA transport from the shoot to the root tip was greater than 3.5 cm h(-1) and (ii) naphthylphthalamic acid (NPA)-induced reduction of polar auxin transport in the shoot did not influence the number of lateral roots in SH-seedlings. It is proposed that high humidity conditions accelerate the phloem-based transport of IAA from the leaf to the root, resulting in an increase in the number of lateral roots.

    OXFORD UNIV PRESS, 2007, JOURNAL OF EXPERIMENTAL BOTANY, 58 (7), 1695 - 1704, English

    [Refereed]

    Scientific journal

  • Tomoki Tabuchi, Tomoyuki Okada, Tetsushi Azuma, Takashi Nanmori, Takeshi Yasuda

    Phosphoethanolamine N-methyltransferase (PEAMT) is involved in choline biosynthesis in plants. The 5' untranslated region (UTR) of several PEAMT genes was found to contain an upstream open reading frame (uORF). We generated transgenic Arabidopsis calli that expressed a chimeric gene constructed by fusing the 5' UTR of the Arabidopsis PEAMT gene (AtNMT1) upstream of the beta-glucuronidase gene. The AtNMT1 uORF was found to be involved in declining levels of the chimeric gene mRNA and repression of downstream beta-glucuronidase gene translation in the calli when the cells were treated with choline. Further, we discuss the role of the uORF.

    TAYLOR & FRANCIS LTD, Sep. 2006, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 70 (9), 2330 - 2334, English

    [Refereed]

    Scientific journal

  • T Hadiarto, T Nanmori, D Matsuoka, T Iwasaki, K Sato, Y Fukami, T Azuma, T Yasuda

    We have constructed a series of deletion mutants of Arabidopsis MAPK kinase kinase (AtMEKK1) and obtained a constitutively active mutant, At-MEKK1 Delta 166, which lacks in self-inhibitory sequence of N-terminal 166 amino acids but still has substrate specificity. AtMEKK1 Delta 166 predominantly phosphorylates AtMEK1, an Arabidopsis MAPKK, but not its double mutant (AtMEKIT218A/S224E), suggesting that Thr-218 and Ser-224 are the phosphorylation sites. In wounded seedlings, AtMEKK1 was activated and phosphorylated its downstream AtMEK1. Furthermore, analysis using anti-AtMEKK1 and anti-AtMEK1 antibodies revealed that the interaction between the two proteins was signal dependent. These results suggest the presence of AtMEKK1-AtMEK1 pathway induced by wounding.

    SPRINGER, Mar. 2006, PLANTA, 223 (4), 708 - 713, English

    [Refereed]

    Scientific journal

  • Azuma Tetsushi, Honda Takenori, Sadai Ayako, Sasayama Daisuke, Itoh Kazuyuki

    CROP SCIENCE SOCIETY OF JAPAN, 2006, Abstracts of Meeting of the CSSJ, 222, 226 - 226

  • Tomoki Tabuchi, Tomoyuki Okada, Yuhei Takashima, Tetsushi Azuma, Takashi Nanmori, Takeshi Yasuda

    Beta vulgaris L. accumulates a large amount of glycinebetaine (betaine), a metabolite that is related to salt-tolerance. Production of betaine involves expression of many genes that encode enzymes such as betaine aldehyde dehydrogenase, choline monooxygenase, phosphoethanolamine N-methyltransferase, S-adenosyl-L-methionine synthetase, S-adenosyl-L-homocysteine hydrolase, and methionine synthase. We examined transcriptional regulation of the betaine-related genes in leaf beet (Beta vulgaris L. var cicla, cv. shirogukifudanna). Transcript expression of these betaine-related genes in leaf tissue had the following common features: (1) a similar pattern of transcript induction under salt stress, (2) reduced induction under salt stress in a dark condition, and (3) diurnal rhythms of transcript levels under a photoperiod of 16 h light/8 h darkness. The co-regulation of transcripts may contribute to the effective betaine production without disturbing the biosynthesis of other products in leaf beet. Copyright © 2006 The Japanese Society for Plant Cell and Molecular Biology.

    Japanese Society for Plant Cell and Molecular Biology, 2006, Plant Biotechnology, 23 (3), 317 - 320, English

    [Refereed]

    Scientific journal

  • AZUMA Tetsushi, OKITA N, NANMORI Takashi, YASUDA Takeshi

    2005, Plant Production Science, 8 447-453 (b)(c), English

    [Refereed]

    Scientific journal

  • AZUMA Tetsushi, OKITA N, NANMORI Takashi, YASUDA Takeshi

    2005, Plant Production Science, 8 441-446 (b)(c), English

    [Refereed]

    Scientific journal

  • TABUCHI Tomoki, KAWAGUCHI Y, AZUMA Tetsushi, NANMORI Takashi, YASUDA Takeshi

    2005, Plant & Cell Physiology, 46 505-513(c), English

    [Refereed]

    Scientific journal

  • AZUMA TETSUSHI, Okita N, Nanmori T, Yasuda T

    Internodes of floating rice (Oryza sativa L.) elongate rapidly when treated with gibberellic acid (GA3) . When p-coumaric or ferulic acid was applied to floating rice stem segments that had been induced to elongate rapidly by treatment with GA3, the extent of internodal elongation decreased in a dose-dependent manner; in particular, ferulic acid was more effective. Application of p-coumaric or ferulic acid also increased the contents of p-coumaric, ferulic and 5-5-diferulic acids in the cell walls of the internodal elongation zone. In these stem segments, the content of ferulic or 5-5-diferulic acid showed a higher correlation with the decrease in internodal elongation compared with the content of p-coumaric acid. These facts suggest that the deposition of ferulic and 5-5-diferulic acids in cell walls is one of the causes of the reduction of internodal elongation in floating rice.

    Japanese Society for Tropical Agriculture, 2005, Japanese Journal of Tropical Agriculture, 49 (3), 215 - 219, English

    [Refereed]

    Scientific journal

  • Interactions between abscisic acid, ethylene and gibberellin in internodal elongation in floating rice: the promotive effect of abscisic acid at low humidity

    T Azuma, T Hatanaka, N Uchida, T Yasuda

    The enhancement of internodal elongation in floating or deepwater rice (Oryza sativa L. cv. Habiganj Aman II) by treatment with ethylene or gibberellic acid (GA(3)) at high relative humidity (RH) is inhibited by abscisic acid (ABA). Here, we examined the interactive effects of ethylene, gibberellin (GA) and ABA at low RH on internodal elongation of deepwater rice stem segments. Although ethylene alone hardly promoted internodal elongation of stem sections at 30% RH, it enhanced the internodal elongation induced by GA(3). Application of ABA alone to stem segments had no effect on internodal elongation. However, in the presence of ethylene and GA(3) at 30% RH, ABA further promoted internodal elongation. This promotive effect of ABA was not found in the internodes of stem segments treated either with ethylene or with GA(3) at 30% RH or in the internodes of stem segments treated with ethylene and/or GA(3) at 100% RH.

    KLUWER ACADEMIC PUBL, Oct. 2003, PLANT GROWTH REGULATION, 41 (2), 105 - 109, English

    [Refereed]

    Scientific journal

  • Enhancement of transpiration by ethylene is responsible for absence of internodal elongation in floating rice at low humidity

    T Azuma, T Hatanaka, N Uchida, T Yasuda

    Internodal elongation in floating rice (Oryza sativa) is known to be enhanced by treatment with ethylene or gibberellic acid (GA(3)) at high relative humidity (RH). However, ethylene-induced internodal elongation is inhibited at low RH, while GA(3)-induced internodal elongation is hardly affected by humidity. We examined the effects of ethylene and GA3 on the rate of transpiration in stem segments incubated at 30 % or 100 % RH. Ethylene promoted the transpiration of stem segments at 30 % RH. but not at 100% RH, while GA(3) had little effect on transpiration at either 30% or 100% RH. We propose that the absence of ethylene-induced internodal elongation at low RH is due, at least in part, to ethylene-induced transpiration.

    URBAN & FISCHER VERLAG, Sep. 2003, JOURNAL OF PLANT PHYSIOLOGY, 160 (9), 1125 - 1128, English

    [Refereed]

    Scientific journal

  • The expression of a germin-like protein with superoxide dismutase activity in the halophyte Atriplex lentiformis is differentially regulated by wounding and abscisic acid

    T Tabuchi, T Kumon, T Azuma, T Nanmori, T Yasuda

    The cDNA clone encoding a putative germin-like protein (GLP) was isolated from the halophyte Atriplex lentiformis (Torr.) Wats. The deduced amino acid sequence of the protein showed high homology to those of various plant germins or germin-like proteins. The protein was designated as AlGLP (A. lentiformis germin-like protein). It was found that AlGLP has superoxide dismutase (SOD; EC 1.15.1.1) activity by in-gel SOD assays after immunoprecipitation, and that it is a glycosylated oligomer in native form. The AlGLP was strongly expressed in calli and weakly in roots, but not in stems or leaves. Interestingly, the transcript level in roots was decreased by salt or abscisic acid (ABA) treatment. We present evidence that the accumulation level of AlGLP mRNA in leaves is increased by methyl jasmonate treatment or wounding, and that the induction is suppressed by ABA treatment. These results suggest that AlGLP expression is increased to fulfil H-2 O-2 supply to modify the structure of cell wall in response to wounding.

    BLACKWELL MUNKSGAARD, Aug. 2003, PHYSIOLOGIA PLANTARUM, 118 (4), 523 - 531, English

    [Refereed]

    Scientific journal

  • Thong PT, Azuma T, Nanmori T, Yasuda T. Equilibrium moisture content of coffee bean.

    Thong PT, Azuma T, Nanmori T, Yasuda T

    2002, 神戸大学農学部学術報告, 26, 27 - 34

    [Refereed]

    Research institution

  • S. M. Nurul Amin, Uchida Naotsugu, HATANAKA TOMOKO, Azuma Tetsushi, Yasuda Takeshi, Tsugawa Hyoue

    Appropriate and effective nitrogen (N) use is an important factor to realize the sustainable rice production and to avoid environmental pollution. In this study, the low N conditions were induced by two different treatments; the restricted supply of N fertilizer by soil culture and the sudden depression of N by water culture. The growth responses of eight varieties of indica rice to low N supply were analyzed using fundamental growth parameters and specific nitrogen utilization rate (NUR) . The relative growth rate (RGR) was generally higher in the local varieties than improved varieties in both experiments. The net assimilation rate (NAR) showed a close correlation with RGR, whereas the specific leaf area and leaf weight ratio did not. A highly positive correlation was found between RGR and NUR. Among the local varieties, Pokkali showed the highest RGR, NAR and NUR in both experiments. These results indicated that under low N supply, the growth rates of the local varieties were higher than those of the improved varieties due to their higher NAR and NUR.

    Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists, 2002, Environmental Control in Biology, 40 (2), 195 - 200, English

    [Refereed]

    Scientific journal

  • S. M. Nurul Amin, Naotsugu Uchida, Tetsushi Azuma, Tomoko Hatanaka, Takeshi Yasuda

    The in vivo photosynthetic performance of indica rice (eight varieties) leaves at varying nitrogen supply levels in solution culture and possible role of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) in regulating photosynthesis were studied. In all the varieties studied, a linear correlation was observed between the oxygen evolution rate (OER) and Rubisco amounts less than 2g m-2. The OER tended to become saturated at Rubisco levels higher than 2 g m-2. Among the traditional and improved varieties, Pokkali, Baisbish and IR 442-2-58 showed a high OER/Rubisco ratio. Based on our regression fitting, the rice varieties were classified into high or low Rubisco efficiency group.

    Japanese Society for Tropical Agriculture, 2002, Japanese Journal of Tropical agriculture, 46 (3), 161 - 165, English

    [Refereed]

    Scientific journal

  • Tetsushi Azuma, Naotsugu Uchida, Takeshi Yasuda

    Submergence induces rapid elongation of internodes in floating rice (Oryza sativa L. cv. Habiganj Aman II). The initial signal for such internodal elongation has been considered to be the reduced partial pressure of oxygen in submerged internodal cavities, which promotes the elongation of internodes through the enhancement of ethylene synthesis. We examined the relationship between low oxygen pressure and ethylene production in the rapid elongation of floating rice internodes using ethylene biosynthesis inhibitors, aminooxyacetic acid (AOA) and CoCl2. When floating rice stem segments were incubated in an atmosphere of low O2, internodal elongation accelerated and ethylene production increased. However, in stem segments treated with AOA or CoCl2, low O2 still stimulated the elongation of internodes although the ethylene production by the internodes was less than by those in control stem segments where internodal elongation was not promoted. These results indicate that low O2 is capable of causing rapid elongation of internodes of floating rice independently of enhanced production of ethylene. In addition to low O2, submergence, ethylene and gibberellic acid each enhanced the production of ethylene by internodal tissues, suggesting that enhanced ethylene production is a common phenomenon accompanied by the acceleration of internodal elongation in floating rice.

    2001, Plant Growth Regulation, 34 (2), 181 - 186, English

    [Refereed]

    Scientific journal

  • グロリオーサ塊茎のin vitro 培養による大量増殖に関する研究

    王 永民, 秋山真介, 東 哲司, 南森隆司, 安田武司

    2000, 神戸大学大学院自然科学研究科紀要 B, 18, 117 - 122

    [Refereed]

    Research institution

  • Light dependent activation of CO2 assimilation and the ratio of Rubisco activase to Rubisco during leaf aging of rice (Oryza sativa)

    H Fukayama, N Uchida, T Azuma, T Yasuda

    The effects of the ratio of Rubisco activase to Rubisco (activase/Rubisco ratio) on light dependent activation of CO2 assimilation were investigated during leaf aging of rice. Changes of photosynthetic CO2 gas exchange rates in relation to step increases of light intensity from two photon flux densities of 60 mu mol m(-2) s(-1) (low initial PFD) and 500 mu mol m(-2) s(-1) (high initial PFD) to saturated PFD of 1800 mu mol m(-2) s(-1) were measured. These photosynthetic activation processes were considered to be limited by the Rubisco activation rate when analyzed by the relaxation method. The relaxation time of low initial PFD gradually declined from 3 to 33 days after leaf emergence and showed high and negative correlation to the activase/Rubisco ratio. The initial rate of Rubisco activation under low initial PFD linearly correlated to the amounts of Rubisco activase, whereas these were almost constant from 3 to 23 days after leaf emergence. But these correlations could not be recognized in the case of high initial PFD. Moreover, the relaxation times were more sensitive to intercellular CO2 concentration (C-i) under high initial PFD than under low initial PFD; especially, at C-i below 300 mu l l(-1) These results suggest the involvement of the activase/Rubisco ratio in the photosynthetic activation under relatively low initial PFD, and the limitation of photosynthetic activation under relatively high initial PFD by Rubisco carbamylation during leaf aging of rice.

    MUNKSGAARD INT PUBL LTD, Dec. 1998, PHYSIOLOGIA PLANTARUM, 104 (4), 541 - 548, English

    [Refereed]

    Scientific journal

  • Tatsuya Hirano, Naotsugu Uchida, Tetsushi Azuma, Takeshi Yasuda

    Floating rice (Oryza sativa L.) responds to submergence by rapid internodal elongation. This stimulated growth needs an increase in the supply of photoassimilates. We investigated the effects of submergence on the export rate of photoassimilates determined by a 13C-tracer experiment and the activity of sucrose phosphate synthase (SPS), a key enzyme in the sucrose biosynthesis pathway, in floating rice. Plants at the 9.5 leaf stage were submerged up to the tip of the 7th leaf blade for 5 days. Export rates of the 13C-photoassimilates at the 9th (9L) and 10th (10L) leaf blades were much higher in the submerged plants than in the control. In order to analyze the activation state of SPS, the activities of SPS were assayed under saturated substrates (Vmax) and limiting substrates plus Pi (Vlimiting). The Vlimiting of SPS of the 9L and 10L were higher in the submerged plants than in the control, whereas the Vmax did not differ between both plots. These results indicate that the SPS of the leaves in the upper position was more highly activated in the submerged plants. Moreover, the Vlimiting of SPS was correlated positively with the export rate. These results suggest that an increase in the Vlimiting of SPS induced by a high activation state might accelerate the export rates of photoassimilates, and that this is probably one of the important factors that support the supply of photoassimilates required for the rapid growth of the sink organs in submerged floating rice.

    Crop Science Society of Japan, 1997, Japanese Journal of Crop Science, 66 (4), 675 - 681, English

    [Refereed]

    Scientific journal

  • Tetsushi Azuma, Satoshi Ueno, Naotsugu Uchida, Takeshi Yasuda

    Internodal elongation in floating rice (Oryza sativa L. cv. Habiganj Aman II) is known to be enhanced by treatment with ethylene or gibberellic acid (GA3) at high relative humidity (RH). However, ethylene-induced internodal elongation is inhibited at low RH, while GA3-induced internodal elongation is hardly affected by humidity. We examined the possible involvement of osmoregulation in the stimulation by GA3 of the elongation of internodes at low RH. Submergence and treatment with ethylene or GA3 at 100% RH increased the osmotic potential in internodes of excised stem segments, while GA3 at 20% RH maintained the osmotic potential at a low level. In internodes of stem segments that had been treated with GA3 at 20% RH, the activity of invertase and the level of soluble sugars were almost 2- and 1.5-fold higher, respectively, than those in internodes that had been treated with GA3 at 100% RH. These results indicate that one of the possible mechanisms by which GA3 promotes elongation of internodes at low RH involves the osmoregulation that is achieved by promotion of the synthesis of invertase.

    Blackwell Publishing Ltd, 1997, Physiologia Plantarum, 99 (4), 517 - 522, English

    [Refereed]

    Scientific journal

  • Tetsushi Azuma, Yoriko Sumida, Yasushi Kaneda, Naotsugu Uchida, Takeshi Yasuda

    Springer Science and Business Media LLC, Jul. 1996, Plant Growth Regulation, 19 (2), 183 - 187

    [Refereed]

    Scientific journal

  • Relationships between photosynthetic activity and the amounts of Rubisco activase and Rubisco in rice leaves from emergence through senescence

    H Fukayama, N Uchida, T Azuma, T Yasuda

    Photosynthetic activity determined as O-2, evolution (OER) and the amounts of Rubisco activase, Rubisco, total soluble protein and chlorophyll were investigated in the 10th leaf of rice, Oryza sativa L. cv. Nipponbare, in relation to its aging. The Rubisco activase content increased until the 17th day after leaf emergence, at which time it attained its maximum and accounted for 1.43% of total soluble protein thereafter, it decreased rapidly. This change was most remarkable compared to the other leaf constituents examined. The Rubisco content had already reached its maximum 3 days after leaf emergence and had begun to decrease earliest among the leaf constituents. The OER depended linearly on the leaf Rubisco content below the value of 3 g m(-2), but tended to saturate above this value. On the contrary, the amount of Rubisco activase and OER were linearly correlated during the life span of the leaf. The in vivo Rubisco activity, as the OER per unit Rubisco content, increased exponentially with the increased Rubisco activase/Rubisco ratio. These results show that the amount of Rubisco activase is closely related to the photosynthetic rates in rice leaf from its emergence through senescence, and suggest that in vivo Rubisco activity can be restricted by Rubisco activase content, particularly when the leaf is young and accumulates excess Rubisco.

    CROP SCIENCE SOC JAPAN, Jun. 1996, JAPANESE JOURNAL OF CROP SCIENCE, 65 (2), 296 - 302, English

    [Refereed]

    Scientific journal

  • Tatsuya Hirano, Naotsugu Uchida, Tetsushi Azuma, Takeshi Yasuda

    Floating rice plants adapt to submergence by rapid internodal elongation. In this study, we examined the changes in the distribution of photoassimilates using 13G and the activities of enzymes involved in sucrose metabolism of floating rice plants under submergence. Total (per plant) and specific (per soluble protein) activities of acid invertase (AI) of the rapidly elongating 9th internode increased remarkably 1 day after submergence. These increases corresponded to the accumulation of hexose. It is likely that the increased AI activities of the 9th internode in the submerged plant promoted the hydrolysis of sucroce and maintained the turgor pressure in the elongating cells. Total sucrose synthase (SS) activity of the 9th internode in the submerged plant increased markedly after 3 days and corresponded to the accumulation of dry matter. Comparing each value in the submerged plants with the control, the distribution of photoassimilates to the uppermost 9th internode increased considerably, while there was a decline in the 8th internode. These changes were in agreement with the changes in activities of AI and /or SS. Sucrose/hexose ratio of the 9th internode also declined under submergence. These results suggest that the changes in the activities of the enzymes involved in sucrose metabolism may be related to the changes in the distribution of photoassimilates to the sink organs of submerged floating rice plants via the increase in the magnitude of the sucrose concentration gradients which exist between source and sink.

    Crop Science Society of Japan, 1996, Japanese Journal of Crop Science, 65 (3), 540 - 548, Japanese

    [Refereed]

    Scientific journal

  • THE ROLE OF ETHYLENE IN SOMATIC EMBRYOGENESIS FROM LEAF DISCS OF COFFEA-CANEPHORA

    T HATANAKA, E SAWABE, T AZUMA, N UCHIDA, T YASUDA

    The role of ethylene in the formation of somatic embryos from leaf discs of Coffea canephora was studied on a medium that contained a cytokinin, iso-pentenyladenine, as the sole plant growth regulator. During incubation under these conditions, explants always produced a small amount of ethylene. Removal of this ethylene by an absorbent reduced the number of somatic embryos induced by the cytokinin, Application of inhibitors of the production of ethylene (Co2+ ions) and of the action of ethylene (Ag+ ions) inhibited the formation of embryos. Exogenous ethylene gas (12 mu l/l) partially overcame the effect of Co2+ ions. These results indicate that ethylene plays an important role in regulating somatic embryogenesis in leaf cultures of Coffea canephora.

    ELSEVIER SCI PUBL IRELAND LTD, Jun. 1995, PLANT SCIENCE, 107 (2), 199 - 204, English

    [Refereed]

    Scientific journal

  • Amino acids on somatic embryogenesis in Coffea arabica

    Nishibata T, Azuma T, Uchida N, Yasuda T

    1995, 16TH INTERNATIONAL SCIENTIFIC COLLOQUIUM ON COFFEE, VOLS I & II, 839 - 844

  • HIRANO Tatsuya, KOSHIMURA Hideyo, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    In floating rice, internodal elongation is markedly promoted under submergence. The increase in the supply of photoassimilates to the rapidly elongating internodes is essential for floating rice grown under submergence. Our objectives were to analyze the changes in the sink activity of each organ and in the distribution pattern of photoassimilates to each organ immediately after submergence, using 13C as a tracer. Also, the rate of sucrose formation was determined in order to investigate the effect of submergence on the source activity. In the present study, the plants in which the source organ was restricted to the first expanded leaf attached above the uppermost internode were used. The translocation of carbon to the uppermost internode was promoted immediately after submergence. In contrast, submergence depressed the increase of dry weight and the percentage distribution of labelled carbon in the lower organs. Therefore, these results indicate that floating rice plants modify the distribution pattern of photoassimilates to promote growth under submergence, and that these characteristics may enable floating rice to utilize efficiently the photoassimilates in order to survive under deep water. Submergence led to a sizeable increase in the sucrose/starch ratio of the first expanded leaf attached above the rapidly elongating uppermost internode. These results suggest that submergence increases the source activity in the upper leaves above the water surface. This assumption was consistent with the increase of the photosynthetic rate per unit leaf area of the uppermost expanded leaf above the water surface under submergence reported previously.

    Japanese Society for Tropical Agriculture, 1995, Tropical Agriculture and Development, 39 (3), 177 - 183, English

  • Tetsushi Azuma, Tatsuya Hirano, Yukiko Deki, Naotsugu Uchida, Takeshi Yasuda, Tadashi Yamaguchi

    Submergence induces rapid internodal elongation in floating rice (Oryza sativa L.). The involvement of abscisic acid (ABA) in such internodal elongation has been examined. Application of ABA to stem sections reduced the extent of internodal elongation induced by submergence, ethylene, or gibberellic acid (GA3). Submergence and treatment with ethylene decreased the levels of ABA in plants and stem sections. This result indicates that a decrease in levels of ABA is involved in the internodal elongation induced by ethylene, the level of which increases in internodes during submergence. However, when plants or stem sections were treated with ethylene at low relative humidity, the levels of ABA decreased but internodes barely increased in length. Moist surroundings, such as submerged conditions, may be necessary if the decrease in levels of ABA is to lead to internodal elongation in floating rice. © 1995, Gustav Fischer Verlag, Stuttgart. All rights reserved.

    Lead, 1995, Journal of Plant Physiology, 146 (3), 323 - 328, English

    [Refereed]

    Scientific journal

  • Effect of plant hormones on somatic embryogenesis of Coffea canephora

    T Hatanaka, T Azuma, N Uchida, T Yasuda

    ASSOC SCIENTIFIQUE INT CAFE, 1995, 16TH INTERNATIONAL SCIENTIFIC COLLOQUIUM ON COFFEE, VOLS I & II, 16, 790 - 797, English

    International conference proceedings

  • AZUMA Tetsushi, UCHIDA Naotsugu, YASUDA Takeshi, YAMAGUCHI Tadashi

    When floating rice (Oryza sativa L. cv Habiganj Aman II) plants are grown under submergence, the levels of endogenous gibberellin and ethylene increase. We examined the role of gibberellin in the increase of the level of endogenous ethylene in the internodes of floating rice. When excised stem sections were treated with gibberellic acid in ambient air or in water, internodal elongation and ethylene production were induced. Also, the activities of 1-aminocyclopropane-1-carboxylic acid synthase and ethylene-forming enzyme were stimulated in the internodes. In stem sections submerged in a solution of 0.1 mM ancymidol, an inhibitor of gibberellin biosynthesis, internodal elongation and ethylene level in the internodes were reduced to about half and two-thirds, respectively, compared with stem sections submerged in distilled water. These results indicate that gibberellin has a promotive effect on ethylene synthesis in floating rice internodes.

    Lead, Japanese Society for Tropical Agriculture, 1994, Japanese Journal of Tropical Agriculture, 38 (1), 78 - 82, English

    [Refereed]

  • Tetsushi Azuma, Fumiko Mihara, Naotsugu Uchida, Takeshi Yasuda, Tadashi Yamaguchi

    Lead, Oxford University Press (OUP), Mar. 1991, Plant and Cell Physiology, 32 (2), 307 - 309

    [Refereed]

    Scientific journal

  • AZUMA Tetsushi, MIHARA Fumiko, UCHIDA Naotsugu, YASUDA Takeshi, YAMAGUCHI Tadashi

    The effects of several plant hormones on the internodal elongation of stem sections and endogenous levels of gibberellin in submerged and ethylene-treated stem sections were investigated in floating rice (Oryza sativa L. cv Habiganj Aman II) . Gibberellic acid (GA3) and ethylene induced internodal elongation of stem sections. Abscisic acid (ABA) and benzyl adenine (BA) at any concentration (≤ 1 mM) did not promote the internodal elongation of the sections regardless of the presence of GA3. However, indoleacetic acid (IAA) (0.1 to 10 μM) promoted the internodal elongation induced by GA3. Submergence increased the endogenous level of gibberellin in the stem sections unlike ethylene. It is suggested that gibberellin and ethylene as well as IAA may be involved in the internodal elongation of floating rice. Also, both gibberellin and ethylene may be involved in different processes of internodal elongation of floating rice under submergence.

    Lead, Japanese Society for Tropical Agriculture, 1990, Japanese Journal of Tropical Agriculture, 34 (4), 271 - 275, English

    [Refereed]

  • AZUMA Tetsushi, MIHARA Fumiko, UCHIDA Naotsugu, YASUDA Takeshi, YAMAGUCHI Tadashi

    Internodal elongation and endogenous ethylene concentration were analysed in floating or deep water rice stem sections submerged at different water depths. The elongation rate of the internodes was independent of the water depth. Elongation rate and ethylene concentration of the internodes were high in the stem sections submerged completely in water, but they decreased when parts of the stem sections were above the water surface. In the stem sections previously submerged, in which the ethylene levels were high, internodal elongation continued after parts of the sections were exposed to ambient air even though the ethylene levels decreased. These results suggest that internodal elongation is independent of the water pressure and that the different concentrations of internodal ethylene partially reflect the difference in the diffusion rate of ethylene in water. They also suggest that ethylene acts as a trigger of internodal elongation.

    Lead, Japanese Society for Tropical Agriculture, 1990, Japanese Journal of Tropical Agriculture, 34 (4), 265 - 270, English

    [Refereed]

  • UCHIDA Naotsugu, OHWAKI Hidetoshi, AZUMA Tetsushi, YASUDA Takeshi, YAMAGUCHI Tadashi

    異なる水位上昇速度下で栽培した浮稲の主稈と分げつの乾物生産並びに葉面積の変化を調べた.深水により弱小な2次分げつの乾物生長速度が低下するのに対し, 主稈や1次分げつのそれはむしろ大きく, 稈への乾物分配も大きくなった.すなわち, 浮稲は個体の生長に最も有利になるようにシンク・ソースのバランスを変化させて深水条件に対応しているものと考えられた.

    Japanese Society for Tropical Agriculture, 1989, Tropical Agriculture and Development, 33 (4), 253 - 260, Japanese

    [Refereed]

  • UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi, YAMAGUCHI Tadashi

    浮稲14品種および非浮稲3品種に, 約8.5葉期から1日当り4cmの速度で20日間水位上昇処理を行い, 処理開始時, 12日目および20日目に草丈, 最上位カラー部の高さ, 総節間長, 葉面積, 乾物重を測定した.得られた結果から生長関数を求め, 各部位の伸長速度とそれら関数との関係について検討した.相対生長率 (RGR) あるいは乾物生長速度 (GR) と葉面積に関する生長関数との間には, 全葉面積よりも水面上の葉面積を対象とした場合により有意な正の相関関係が認められた.RGRやGRとの間には, 純同化率 (NAR) はいずれの期間においても高い正の相関を示すが, 葉面積比や平均葉面積は水位が高くなった処理後半において相関が高くなった.NARと各部位の伸長速度とは無関係であるのに対し, 相対葉面生長率は節間長や最上位カラー部の高さの変化と密接な関係があった.

    Japanese Society for Tropical Agriculture, 1989, Tropical Agriculture and Development, 33 (3), 164 - 172, Japanese

    [Refereed]

MISC

  • Responsiveness of Expression of Starch Synthesis-Related Genes to CRCT in Vegetative Organs of Rice

    宮川文宏, 森田隆太郎, 笹山大輔, 畠中知子, 東哲司, 深山浩

    2023, 日本作物学会講演会要旨集, 255th

  • Effect of gravity and light on growth direction in crown roots of floating rice

    TSUBOTA Hiroki, SASAYAMA Daisuke, ITOH Kazuyuki, AZUMA Tetsushi

    09 Sep. 2013, 日本作物學會紀事, 82, 342 - 243, Japanese

  • Low-oxygen-induced intemodal elongation in floating rice

    HARADA Shohei, ITO Shunsuke, SASAYAMA Daisuke, HIRANO Tatsuya, ITOH Kazuyuki, AZUMA Tetsushi

    09 Sep. 2013, 日本作物學會紀事, 82, 346 - 347, Japanese

  • Effect of gravity on elongation growth of rice

    ISHIHARA Ruriko, AZUMA Tetsushi, ITOH Kazuyuki

    09 Sep. 2012, 日本作物學會紀事, 81, 310 - 311, Japanese

  • Involvement of ethylene in the elongation responses to flood in Amazonian wild rice species, Oryza glumaepatula and O. grandiglumis

    OKISHIO Takuma, AZUMA Tetsushi, ITOH Kazuyuki

    09 Sep. 2012, 日本作物學會紀事, 81, 306 - 307, Japanese

  • Relationship between Energy Status and Gravitropic Response of Cerial Crops in Anoxia

    HAMADA Yuma, AZUMA Tetsushi, ITOH Kazuyuki

    09 Sep. 2012, 日本作物學會紀事, 81, 308 - 309, Japanese

  • Gaseous factors of regulating internode elongation during sprouting of tubers in Sagittaria trifolia L. and S. pygmaea Miq.

    SAKAI Hisateru, AZUMA Tetsushi, ITOH Kazuyuki

    09 Sep. 2012, 日本作物學會紀事, 81, 312 - 313, Japanese

  • Response to flash flood in South American wild rice species

    HIGAMI Toshiaki, OKISHIO Takuma, ITOH Kazuyuki, AZUMA Tetsushi

    30 Aug. 2011, 日本作物學會紀事, 80, 244 - 245, Japanese

  • Effect of Deposition of Phenolic Substances and Polysaccharides on Susceptibility to Expansins in the Cell Wall of Floating Rice Internodes

    OHTA Kensuke, SASAYAMA Daisuke, ITOH Kazuyuki, AZUMA Tetsushi

    30 Aug. 2011, 日本作物學會紀事, 80, 224 - 225, Japanese

  • Responces to a rapid rise in water level in the South American wild rice species Oryza grandiglumis and O. glumaepatula

    OKISHIO Takuma, AZUMA Tetsushi, ITOH Kazuyuki

    03 Sep. 2010, 日本作物學會紀事, 79, 252 - 253, Japanese

  • Comparison of Gravitropic Response of Shoots to Anoxia in Cereal Crops

    INOUE Yoshitaka, AZUMA Tetsushi, ITOH Kazuyuki

    03 Sep. 2010, 日本作物學會紀事, 79, 250 - 251, Japanese

  • Differences between Sagittaria trifolia and S. pygmaea in the properties of organs developing from tubers during emergence

    IKEMACHI Kenta, AZUMA Tetsushi, ITOH Kazuyuki

    03 Sep. 2010, 日本作物學會紀事, 79, 398 - 399, Japanese

  • Effect of submergence and irradiance on internodal elongation of floating rice

    AZUMA Tetsushi, SADAI Ayako, ITOH Kazuyuki

    27 Mar. 2009, 日本作物學會紀事, 78, 308 - 309, Japanese

  • Floating ability of Oryza grandiglumis and O. glumaepatula

    OKISHIO Takuma, AZUMA Tetsushi, ITOH Kazuyuki

    27 Mar. 2009, 日本作物學會紀事, 78, 304 - 305, Japanese

  • Effect of the Deposition of Ferulic and Diferulic Acids on the Susceptibility to Expansin Action in the Cell Walls of Floating Rice Internodes

    SASAYAMA Daisuke, AZUMA Tetsushi, ITOH Kazuyuki

    27 Mar. 2009, 日本作物學會紀事, 78, 300 - 301, Japanese

  • Growth in Internodes of Floating Rice: Hormonal Regulations and Cell Wall Modifications

    Tetsushi Azuma, Daisuke Sasayama, Kazuyuki Itoh

    Floating rice is the only crop that can be grown in flood plains because of the capacity to elongate internodes rapidly under conditions of flooding. The mechanisms of growth adaptation to flooding stress have been investigated from ecological, morphological, genetical, physiological, biochemical and molecular biological points of view. In this review, we mainly describe our r

    The Crop Science Society of Japan, Jan. 2009, Japanese Journal of Crop Science, 78 (1), 1 - 8, Japanese

    [Refereed]

    Introduction scientific journal

  • P-46 Promotion of Shoot Growth by a Low Oxygen Environment in Floating Rice

    Sadai Ayako, Azuma Tetsushi, Itoh Kazuyuki

    The Crop Science Society of Japan, 2008, Japanese Journal of Crop Science, 77 (2), 306 - 307, Japanese

  • P-47 Relationship between Cell Wall Composition and Responsiveness to Expansin in Floating Rice Internodes

    Sasayama Daisuke, Azuma Tetsushi, Itoh Kazuyuki

    The Crop Science Society of Japan, 2008, Japanese Journal of Crop Science, 77 (2), 308 - 309, Japanese

  • Gravitropic response of shoot in floating rice

    Takenaga Y., Sasayama D., Azuma T., Nanmori T., Yasuda T.

    Japanese Society for Tropical Agriculture, 25 Sep. 2003, Japanese journal of tropical agriculture, 47 (2), 29 - 30, Japanese

  • Internodal elongation and enhancement of transpiration by ethylene in floating rice

    AZUMA Tetsushi, HATANAKA Tomoko, UCHIDA Naotsugu, YASUDA Takeshi

    The Crop Science Society of Japan, 17 Sep. 2003, Japanese Journal of Crop Science, 72 (2), 304 - 305, Japanese

  • Changes in expansin activity and response of cell wall during internodal elongation in floating rice

    SASAYAMA Daisuke, AZUMA Tetsushi, NANMORI Takashi, YASUDA Takeshi

    The Crop Science Society of Japan, 17 Sep. 2003, Japanese Journal of Crop Science, 72 (2), 306 - 307, Japanese

  • Low levels of oxygen promote internodal elongation in floating rice independently of enhanced ethylene production

    AZUMA Tetsushi, UCHIDA Naotsugu, YASUDA Takeshi

    The Crop Science Society of Japan, 27 Sep. 2001, Japanese Journal of Crop Science, 70 (2), 193 - 194, Japanese

  • Changes in cell wall(1→3)(1→4)-β-D-glucan levels and glucanase activities in elongating internodes of floating rice

    MURANAGA Jun-ichiro, OKITA Naoko, AZUMA Tetsushi, NANMORI Takashi, YASUDA Takeshi

    The Crop Science Society of Japan, 2001, Japanese Journal of Crop Science, 70 (2), 195 - 196, Japanese

  • POSTULATION OF NEW TYPE AGC-PROTEIN KINASE IN BOTH PLANT & ANIMAL :

    FUJITA Naoya, MATSUOKA Daisuke, NANMORI Takashi, AZUMA Tetsushi, YASUDA Takeshi

    Japanese Society of Plant Physiologists, 2001, Plant and cell physiology, 42, s106, English

  • EFFECT OF OSMOLARITY, DEHYDRATION AND ABA ON AMOUNTS OF ATSRPK1 TRANSCRIPTS :

    KOHNO Tomoko, MATSUOKA Daisuke, NANMORI Takashi, AZUMA Tetsushi, YASUDA Takeshi

    Japanese Society of Plant Physiologists, 2001, Plant and cell physiology, 42, s93, English

  • Changes in the Rate of Catalytic Turnover and the Number of Carbamylated Site of Rubisco during Leaf Aging of Rice

    FUKAYAMA Hiroshi, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    The Crop Science Society of Japan, 02 Apr. 1998, Japanese Journal of Crop Science, 67, 104 - 105, Japanese

  • 68 Photosynthetic Characteristics in Wild Rice Species : The in vivo Activity of Rubisco

    HIRAOKA M., UCHIDA N., FUKAYAMA H., AZUMA T., YASUDA T.

    野生イネO.barthiiとO.meridionalisのin vivoのRubisco比活性は栽培種のそれより有意に高く, Rubiscoの活性比率とRubisco activase含量も高い。

    The Crop Science Society of Japan, 18 Oct. 1997, Japanese Journal of Crop Science, 66 (2), 135 - 136, Japanese

  • 67 Relationship between Specific Degradation of Rubisco and Increased Proteolytic Activity in a Rice Leaf Piece Induced by ABA

    FUKAYAMA Hiroshi, ARAI Rie, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    The Crop Science Society of Japan, 02 Apr. 1997, Japanese Journal of Crop Science, 66 (1), 134 - 135, Japanese

  • 66 Relaxation Time for Activation of CO_2 Exchange Decreases with Leaf Aging and It is Related to Rubisco activase/Rubisco Ratio

    FUKAYAMA Hiroshi, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    The Crop Science Society of Japan, 02 Apr. 1997, Japanese Journal of Crop Science, 66 (1), 132 - 133, Japanese

  • ETHYLENE-INDUCED ELONGATION AND TRANSPIRATION IN INTERNODES OF FLOATING RICE

    AZUMA Tetsushi, HARA Ai, YAMAMURA Noriko, UCHIDA Naotsugu, YASUDA Takeshi

    Mar. 1997, Plant and cell physiology, 38, s116, English

  • 105 Gibberellin-induced elongation and osmoregulation in internodes of floating rice

    AZUMA Tetsushi, UENO Satoshi, UCHIDA Naotsugu, YASUDA Takeshi

    The Crop Science Society of Japan, 02 Oct. 1996, Japanese Journal of Crop Science, 65 (2), 209 - 210, Japanese

  • 88 Photosynthetic characteristics in wild rice species

    Hiraoka Motoaki, Fukayama Hiroshi, Uchida Naotsugu, Azuma Tetsushi, Yasuda Takeshi

    The Crop Science Society of Japan, 02 Oct. 1996, Japanese Journal of Crop Science, 65 (2), 175 - 176, Japanese

  • 54 Changes in translocation of photoassimilates and activities of sucrose synthesis enzymes in floating rice growing rapidly under submergence.

    HIRANO Tatsuya, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    The Crop Science Society of Japan, 03 Apr. 1996, Japanese Journal of Crop Science, 65 (1), 108 - 109, Japanese

  • 42 Effects of Plant growth regulators on photosynthetic activity of senescing rice leaf slices : Rubisco activase, Rubisco and proteinase

    FUKAYAMA Hiroshi, UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    The Crop Science Society of Japan, 03 Apr. 1996, Japanese Journal of Crop Science, 65 (1), 84 - 85, Japanese

  • GIBBERELLIN-INDUCED ELONGATION AND OSMOREGULATION IN INTERNODES OF FLOATING RICE

    AZUMA Tetsushi, UENO Satoshi, UCHIDA Naotsugu, YASUDA Takeshi

    Mar. 1996, Plant and cell physiology, 37, 144 - 144, English

  • 48 Relation between photosynthetic activity and Rubisco activase content in rice leaves from emergence through senescence

    Fukayama Hiroshi, Uchida Naotsugu, Azuma Tetsushi, Yasuda Takeshi

    イネ葉の加齢に伴う光合成速度の変化はRubisco activase含量との関係が最も密接で, in vivoの活性はRubiscoに対するRubisco activaseの比率が高いほど高い.

    The Crop Science Society of Japan, 03 Apr. 1995, Japanese Journal of Crop Science, 64 (1), 96 - 97, Japanese

  • ETHYLENE AND GROWTH IN INTERNODES OFFLOATING RICE UNDER HYPOXIA

    AZUMA Tetsushi, NISHI Fumiko, UENO Satoshi, UCHIDA Naotsugu, YASUDA Takeshi

    Mar. 1995, Plant and cell physiology, 36, S84, English

  • OXYGEN AND GROWTH IN INTERNODES OFSUBMERGED FLOATING RICE

    AZUMA Tetsushi, KANEDA Yasushi, SUMIDA Yoriko, UCHIDA Naotsugu, YASUDA Takeshi

    Mar. 1995, Plant and cell physiology, 36, S84, English

  • ROLE OF ETHYLENE IN SOMATIC EMBRYOGENESISOF COFFEA CANEPHORA

    HATANAKA Tomoko, AZUMA Tetsushi, UCHIDA Naotsugu, YASUDA Takeshi

    Mar. 1995, Plant and cell physiology, 36, S109, English

  • Purification of Rubisco activase from rice leaves

    FUKAYAMA H., Uchida Naotsugu, Azuma Tetsushi, Yasuda Takeshi, Yamaguchi Tadashi

    ゲルろ過とイオン交換クロマトグラフィーにより, イネ葉より Rubisco activase を精製することができた. 12.5% SDS-PAGE の結果それは約40 kDa のペプチドであることがわかった.

    The Crop Science Society of Japan, 1994, Jpn. J. Crop Sci., 63 (1), 140 - 141, Japanese

Books etc

  • 熱帯農学概論

    AZUMA TETSUSHI

    Joint work, 培風館, Jan. 2019, Japanese, ISBN: 9784563078263

    Scholarly book

  • 作物栽培体系7 工芸作物の栽培と利用

    AZUMA TETSUSHI

    Joint work, 朝倉書店, Jul. 2017, Japanese

    Scholarly book

  • 作物学

    AZUMA TETSUSHI

    Joint work, 文永堂出版, Nov. 2013, Japanese

    Scholarly book

  • 作物学用語事典

    AZUMA TETSUSHI

    Joint work, 農山漁村文化協会, Mar. 2010, Japanese

    Scholarly book

Presentations

  • 異なる窒素施与条件が根粒着生能の異なる3種の準同質系統ダイズの種子収量・品質に与える影響解析—完熟種子δ15N値に基づく窒素同化・固定量の評価

    濱口 秀生, 武田 旭永, 山本 直樹, 増村 威宏, 杉本 敏男, AZUMA TETSUSHI

    種子生理生化学研究会, Nov. 2018, Japanese, Domestic conference

    Oral presentation

  • Vernonia galamensis DGAT1 can increase Arabidopsis seed oil level more than other DGAT1s

    HATANAKA TOMOKO, 冨田 典希, 周 采穎, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, DAVID F. HILDEBRAND

    第31回植物脂質シンポジウム, Nov. 2018, Japanese, 高知大学, Domestic conference

    Poster presentation

  • Vernonia galamensis DGAT1 can increase Arabidopsis seed oil content more than other DGAT1s

    HATANAKA TOMOKO, YOSHIKI TOMITA, CHOI-WING CHAU, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, DAVID F. HILDEBRAND

    The 14th International Symposium on Biocatalysis and Agricultural Biotechnology, Oct. 2018, English, Kuala Lumpur, Malaysia, International conference

    Poster presentation

  • Analysis of Floating Response of South American Wild Rice Oryza glumaepatula

    NIIKAWA MAYUKO, ENDO HIROAKI, SASAYAMA DAISUKE, HATANAKA TOMOKO, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    日本作物学会第246回講演会, Sep. 2018, Japanese, 北海道大学農学部, Domestic conference

    Poster presentation

  • 異なる窒素施与条件が根粒着生能の異なる3種の準同質系統ダイズの種子収量・品質に与える影響解析—完熟種子δ15N値に基づく窒素同化・固定量の評価

    濱口 秀生, 武田 旭永, 山本 直樹, 増村 威宏, 杉本 敏男, AZUMA TETSUSHI

    日本土壌肥料学会2018年度大会, Sep. 2018, Japanese, Domestic conference

    Oral presentation

  • Structure-Function Relationship of Hybrid Rubisco Consisting of Sorghum RbcS and Rice RbcL

    SHIOMI KEITA, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, YOSHIKAWA HIROKI, MATSUMURA HIROYOSHI, FUKAYAMA HIROSHI

    日本作物学会第246回講演会, Sep. 2018, Japanese, 北海道大学農学部, Domestic conference

    Oral presentation

  • Growth response of the African cultivated rice Oryza glaberrima and its wild ancestor Oryza barthii to flooding

    Luo Quanshu, NAKAZAWA MISAKI, SASAYAMA DAISUKE, HATANAKA TOMOKO, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    日本作物学会第246回講演会, Sep. 2018, Japanese, 北海道大学農学部, Domestic conference

    Poster presentation

  • Highly active Vernonia galamensis DGAT1 can effectively increase oil levels in yeast, soybean and Arabidopsis

    HATANAKA TOMOKO, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, MATSUOKA DAISUKE, TOMITA YOSHIKI, CHAU CHOI-WING, MIYASHITA WAKANA, SERSON WILLIAM, LI RUNZHI, ARMSTRONG PAUL, YU KESHUN, PFEIFFER TODD, LI XI-LE, HILDEBRAND DAVID

    The 23rd International Symposium on Plant Lipids, Jul. 2018, English, Yokohama, Japan, International conference

    Poster presentation

  • 根粒超着生系統ダイズの低収量の主因は、根粒自身ではない―根粒着生能の異なる三種の同質系統 ダイズへの窒素施与の影響比較―

    濱口 秀生, 武田 旭永, 山本 直樹, 増村 威宏, 杉本 敏男, AZUMA TETSUSHI

    近畿作物・育種研究会 第185回, Jun. 2018, Japanese, Domestic conference

    Oral presentation

  • アフリカイネ Oryza glaberrima とその祖先種 O. barthii の洪水に対する応答

    羅 全淑, 中澤 美沙希, SASAYAMA DAISUKE, HATANAKA TOMOKO, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    近畿作物・育種研究会 第185回例会, Jun. 2018, Japanese, Domestic conference

    Oral presentation

  • シロイヌナズナにおける CRCT オーソログの機能解析

    萩原輝, 中馬望, MATSUOKA DAISUKE, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    日本作物学会講演会, 2018, Japanese, Domestic conference

    Poster presentation

  • イネの Rubisco activase 様タンパク質 Rca2 は Rubisco activase の機能を阻害する

    水本晃那, 小林亜希子, 山内靖雄, MATSUOKA DAISUKE, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    日本作物学会講演会, 2018, Japanese, Domestic conference

    Poster presentation

  • イネRubisco activase様タンパク質OsRca2はRubiscoの活性化を阻害する

    水本晃那, 小林亜希子, MATSUOKA DAISUKE, YAMAUCHI YASUO, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    日本光合成学会講演会, 2018, Japanese, Domestic conference

    Poster presentation

  • Functional analysis of Rubisco small subunit, OsRbcS1, that is not expressed in photosynthetic organs in rice

    小林 則之, 森田 耕一, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    International Symposium on Photosynthesis and Chloroplast Biogenesis, 2018, English, Domestic conference

    Poster presentation

  • C4植物の Rubisco 小サブユニットを高発現する形質転換イネの Rubisco 酵素特性

    小原崇, SASAYAMA DAISUKE, HATANAKA TOMOKO, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    日本作物学会講演会, 2018, Japanese, Domestic conference

    Poster presentation

  • Highly active Vernonia galamensis DGAT1 can effectively increase seed oil levels in soybean and Arabidopsis

    HATANAKA TOMOKO, TOMITA YOSHIKI, Chau, Choi-Wing, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, William Serson, Runzhi Li, Paul Armstrong, Keshun Yu, Todd Pfeiffer, Xi-Le Li, David F. Hildebrand

    The 7th Asian Symposium on Plant Lipid, Nov. 2017, English, Taipei, Taiwan, International conference

    Poster presentation

  • 浮稲性遺伝子と冠水耐性遺伝子を併せ持つイネ品種の深水成長応答と関連遺伝子の発現

    尾江 俊祐, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, HATANAKA TOMOKO, AZUMA TETSUSHI

    日本作物学会第244回講演会, Sep. 2017, Japanese, 岐阜大学, Domestic conference

    Poster presentation

  • 南米野生イネOryza glumaepatulaの深水に対する応答とSNORKEL遺伝子の多様性

    遠藤 宏朗, 新川 麻由子, SASAYAMA DAISUKE, HATANAKA TOMOKO, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    日本作物学会第244回講演会, Sep. 2017, Japanese, 岐阜大学, Domestic conference

    Poster presentation

  • 深水環境下において浮稲節間の伸長を誘導する新規因子の探索

    冨田 一嘉, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, HATANAKA TOMOKO, AZUMA TETSUSHI

    日本作物学会第244回講演会, Sep. 2017, Japanese, 岐阜大学, Domestic conference

    Poster presentation

  • Does Vernonia DGAT1 show a higher activity than other DGAT1s in Arabidopsis seed?

    HATANAKA TOMOKO, TOMITA YOSHIKI, CHAU CHOI-WING, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, David F. Hildebrand

    日本作物学会 第244回講演会, Sep. 2017, Japanese, 岐阜大学, Domestic conference

    Poster presentation

  • シロイヌナズナにおけるベルノニアDGAT1の働き

    HATANAKA TOMOKO, TOMITA YOSHIKI, CHAU CHOI-WING, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, David F. Hildebrand

    第30回植物脂質シンポジウム, Sep. 2017, Japanese, お茶の水大学, Domestic conference

    Poster presentation

  • Vernonia DGAT1 can increase Arabidopsis seed oil content more than other DGAT1s

    HATANAKA TOMOKO, TOMITA YSHIKI, CHAU CHOI-WING, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI, HILDEBRAND, D. F

    Plant Biology 2017, Jun. 2017, English, Honolulu, Hawaii, USA, Plant oils represent one of the world’s most important renewable resources. In addition to extensive food uses, vegetable oils also have value as renewable chemical derivatives and fuels, such as biodiesel. Worldwide production of plant oil has been increasing. Triacylglycerols (TAGs) are the major component of plant storage lipid. Acyl-CoA:diacylglycerol acyltransferase (DGAT), International conference

    Poster presentation

  • マイクロアレイ法によるOsRbcS1発現抑制イネの遺伝子発現プロファイリング

    森田 耕一, SASAYAMA DAISUKE, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    日本作物学会講演会, 2017, Japanese, Domestic conference

    Poster presentation

  • ソルガム高活性型Rubiscoの小サブユニットを利用したイネの光合成能力の改良

    塩見慶太, 山本滉樹人, HATANAKA TOMOKO, SASAYAMA DAISUKE, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    農芸化学会関西支部会, 2017, Japanese, Domestic conference

    Oral presentation

  • イネにおけるRubisco activase様タンパク質OsRca2の機能解析

    水本晃那, 小林亜希子, HATANAKA TOMOKO, SASAYAMA DAISUKE, AZUMA TETSUSHI, FUKAYAMA HIROSHI

    農芸化学会関西支部会, 2017, Japanese, Domestic conference

    Oral presentation

  • 浮稲性遺伝子と冠水耐性遺伝子を併せ持つイネ系統の深水伸長応答

    OE SHUNSUKE, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    日本作物学会 第242回講演会, Sep. 2016, Japanese, 龍谷大学瀬田キャンパス, Domestic conference

    Poster presentation

  • 水田雑草オモダカとウリカワの塊茎萌芽期の節間伸長の酸素欠乏および二酸化炭素による促進

    SASAYAMA DAISUKE, FUKAYAMA HIROSHI, ITOH KAZUYUKI, AZUMA TETSUSHI

    日本作物学会 第242回講演会, Sep. 2016, Japanese, 龍谷大学瀬田キャンパス, Domestic conference

    Oral presentation

  • エチレンとジベレリンが誘導する浮稲節間の伸長促進に及ぼす重力方向と過重力の影響

    NAKATANI YUMI, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    日本作物学会 第242回講演会, Sep. 2016, Japanese, 龍谷大学瀬田キャンパス, Domestic conference

    Poster presentation

  • 浮稲性遺伝子と冠水耐性遺伝子を併せ持つイネ系統の生理特性

    OE SHUNSUKE, SASAYAMA DAISUKE, FUKAYAMA HIROSHI, AZUMA TETSUSHI

    近畿作物・育種研究会 第181回例会, May 2016, Japanese, Domestic conference

    Oral presentation

  • 多年生水田雑草オモダカとウリカワの節間伸長はそれぞれ酸素欠乏と二酸化炭素によって促進される

    SASAYAMA DAISUKE, FUKAYAMA HIROSHI, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第181回例会, May 2016, Japanese, 滋賀県立大学 サテライト教室, Domestic conference

    Oral presentation

  • 野生イネOryza altaおよびO. latifoliaの洪水適応

    平井 雄基, SASAYAMA DAISUKE, AZUMA TETSUSHI

    日本作物学会 第240回講演会, Sep. 2015, Japanese, 信州大学長野 (工学) キャンパス, Domestic conference

    Poster presentation

  • 浮稲における冠水耐性遺伝子SUB1Aの存在とその機能

    岩見 裕太, SASAYAMA DAISUKE, AZUMA TETSUSHI

    日本作物学会 第240回講演会, Sep. 2015, Japanese, 信州大学長野 (工学) キャンパス, Domestic conference

    Oral presentation

  • アマゾン野生イネOryza glumaepatulaの深水適応

    SASAYAMA DAISUKE, 平井 雄基, AZUMA TETSUSHI

    日本作物学会 第240回講演会, Sep. 2015, Japanese, 信州大学長野 (工学) キャンパス, Domestic conference

    Oral presentation

  • アマゾン野生イネOryza glumaepatulaの浮稲性について

    SASAYAMA DAISUKE, AZUMA TETSUSHI

    近畿作物・育種研究会 第179回例会, May 2015, Japanese, 奈良県立橿原考古学研究所, Domestic conference

    Oral presentation

  • 浮稲茎葉部における重力屈性反応へのエクスパンシンの関与

    田口 あみ, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    日本作物学会 第238回講演会, Sep. 2014, Japanese, 愛媛大学 城北キャンパス, Domestic conference

    Poster presentation

  • 浮稲不定根の成長方向と光の関係

    坪田 裕樹, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第177回例会, Jul. 2014, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • 浮稲茎葉部の重力屈性におけるエクスパンシンの関与

    田口 あみ, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第177回例会, Jul. 2014, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • 浮稲におけるSUB1A遺伝子の存在とその分類

    岩見 裕太, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第177回例会, Jul. 2014, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • アマゾン野生イネOryza grandiglumisの浮稲性と冠水耐性

    置塩 琢磨, SASAYAMA DAISUKE, 平野 達也, 秋本 正博, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第177回例会, Jul. 2014, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • Tuber sprouting and emergence of Sagittaria trifolia and S. pygmaea: their physiological traits and regulatory mechanisms

    笹山 大輔, Kenta Ikemachi, Hisateru Sakai, 伊藤 一幸, 東 哲司

    11th Conference of the International Society for Plant Anaerobiosis, Oct. 2013, English, IRRI, Los Baños, Laguna, Philippines, Emergent plants Sagittaria trifolia and S. pygmaea are perennial Alismataceous weeds of paddy field. Those plants mainly propagate vegetatively by tubers. Their sprouting from tubers starts with irrigation for paddling of the rice fields and continues for several months. Sprouting finally leads to emergence of the shoot parts of those plants from the soil. In this study, we cha, International conference

    Poster presentation

  • Effect of gravity and light on growth direction in crown roots of floating rice

    坪田 裕樹, 笹山 大輔, 伊藤 一幸, 東 哲司

    日本作物学会 第236回講演会, Sep. 2013, Japanese, 鹿児島大学 郡元キャンパス, Domestic conference

    Poster presentation

  • 低酸素環境が誘導する浮稲節間の伸長反応

    原田 翔平, 伊藤 俊輔, 笹山 大輔, 平野 達也, 伊藤 一幸, 東 哲司

    日本作物学会 第236回講演会, Sep. 2013, Japanese, 鹿児島大学 郡元キャンパス, Domestic conference

    Poster presentation

  • 浮稲節間の伸長に及ぼす重力の影響とオーキシンの関与

    石原 瑠璃子, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    近畿作物・育種研究会 第175回例会, Jul. 2013, Japanese, 近畿大学生物理工学部, Domestic conference

    Oral presentation

  • イネ葉枕の重力屈性は嫌気環境で促進されるがコムギとエンバク葉枕では阻害される

    AZUMA TETSUSHI, 井上 義隆, 濱田 友馬, SASAYAMA DAISUKE, ITOH KAZUYUKI

    近畿作物・育種研究会 第175回例会, Jul. 2013, Japanese, 近畿大学生物理工学部, Domestic conference

    Oral presentation

  • 浮稲節間細胞壁におけるエクスパンシンの反応性に及ぼすフェノール化合物と多糖の影響

    太田 健介, SASAYAMA DAISUKE, ITOH KAZUYUKI, AZUMA TETSUSHI

    日本作物学会 第232回講演会, Sep. 2011, Japanese, 山口大学農学部, Domestic conference

    Poster presentation

  • 浮稲節間におけるエクスパンシンに対する細胞壁の反応性と壁構造との関係

    SASAYAMA DAISUKE, AZUMA TETSUSHI, ITOH KAZUYUKI

    日本作物学会 第226回講演会, Sep. 2008, Japanese, 神戸大学農学部, Domestic conference

    Poster presentation

  • 山口県の水田から見つかったスルホニルウレア抵抗性ミズマツバとアブノメ

    ITOH KAZUYUKI, 松本 晃, SASAYAMA DAISUKE, AZUMA TETSUSHI, 池尻 明彦, 平田 道弥

    日本作物学会 第226回講演会, Sep. 2008, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • 浮稲の深水条件下での節間伸長におけるエクスパンシンの関与

    SASAYAMA DAISUKE, AZUMA TETSUSHI, ITOH KAZUYUKI

    種生物学会 第39回種生物シンポジウム, Nov. 2007, Japanese, 六甲山YMCA, Domestic conference

    Poster presentation

  • Involvement of expansins in internodal elongation of submerged floating rice

    笹山 大輔, Tetsushi Azuma, Kazuyuki Itoh

    9th Conference of the International Society for Plant Anaerobiosis, Nov. 2007, English, Matushima, Sendai, Japan, International conference

    Poster presentation

  • 浮稲節間の細胞壁におけるエクスパンシンに対する反応性とフェノール性化合物の沈着の関係

    SASAYAMA DAISUKE, AZUMA TETSUSHI, ITOH KAZUYUKI

    日本作物学会 第224回講演会, Sep. 2007, Japanese, 金沢大学角間キャンパス, Domestic conference

    Oral presentation

  • 浮稲節間の伸長停止に伴うエクスパンシンの活性と細胞壁反応性の変化

    SASAYAMA DAISUKE, AZUMA TETSUSHI, NANMORI TAKASHI, 安田 武司

    日本作物学会 第221回講演会, Mar. 2006, Japanese, 東京大学農学部, Domestic conference

    Oral presentation

  • 浮稲節間組織における酸が誘導する成長とエクスパンシンとの関係

    SASAYAMA DAISUKE, AZUMA TETSUSHI, NANMORI TAKASHI, 安田 武司

    近畿作物・育種研究会 第159回例会, Jul. 2005, Japanese, 神戸大学農学部, Domestic conference

    Oral presentation

  • Identification of Substrate Specificity and Downstream Events of Arabidopsis AtMEKK1

    Takashi Nanmori, Toto Hadiart, Azuma Tetsusi, Takeshi Yasuda

    46th anual meeting of Japanese plant physiologists, Mar. 2005, English, nigata, Domestic conference

    Poster presentation

  • 塩ストレス下の塩生植物Atriplex nummulariaにおけるS-adenosylmethionine synthetaseの発現誘導

    多淵 知樹, 川口 祐介, 東 哲司, 南森 隆司, 安田 武司

    日本植物生理学会2004年度年会, 2004, Japanese, 日本植物生理学会, 東京都立大学, Domestic conference

    Oral presentation

  • アカザ科の植物のグリシンベタイン合成に関わる酵素の転写誘導に関する研究

    多淵 知樹, 井上 堅太郎, 佐々木 正浩, 東 哲司, 南森 隆司, 安田 武司

    日本植物生理学会2004年度年会, 2004, Japanese, 日本植物生理学会, 東京都立大学, Domestic conference

    Oral presentation

  • 浮稲節間の伸長に伴うエクスパンシンの活性と細胞壁反応性の変化

    SASAYAMA DAISUKE, AZUMA TETSUSHI, NANMORI TAKASHI, 安田 武司

    日本作物学会 第216回講演会, Sep. 2003, Japanese, 島根大学生物資源科学部, Domestic conference

    Oral presentation

  • 浮稲茎葉部の重力屈性反応について

    武長 裕子, SASAYAMA DAISUKE, AZUMA TETSUSHI, NANMORI TAKASHI, 安田 武司

    日本熱帯農業学会 第94回講演会, Sep. 2003, Japanese, 佐賀大学農学部, Domestic conference

    Oral presentation

  • 浮稲節間の伸長に伴うエクスパンシンの活性と細胞壁反応性の変化

    笹山 大輔, 東 哲司, 南森 隆司, 安田 武司

    日本作物学会記事, 2003, Japanese, 未記入, 未記入, Domestic conference

    Oral presentation

  • 浮稲節間の伸長とエチレンによる蒸散の促進

    東 哲司, 畠中 知子, 内田 直次, 安田 武司

    日本作物学会記事, 2003, Japanese, 未記入, 未記入, Domestic conference

    Oral presentation

  • 浮稲茎葉部の重力屈性反応について

    武長 裕子, 笹山 大輔, 東 哲司, 南森 隆司, 安田 武司

    熱帯農業, 2003, Japanese, 日本熱帯農業学会, 未記入, Domestic conference

    Oral presentation

Research Projects

  • 高温前処理によるイネメソコチル伸長の制御メカニズムの解明と栽培への応用

    東 哲司, 笹山 大輔, 平野 達也

    日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, 01 Apr. 2021 - 31 Mar. 2025

    高温前処理によるメソコチル伸長誘導とジベレリン (GA) の関連について調査を行った。高温前処理によるメソコチル伸長誘導が見られない矮性品種 (短銀坊主) にGAを投与してもメソコチル伸長は見られないが,高温前処理後にGAを投与するとメソコチル伸長誘導がみられたことから,高温前処理によるメソコチル伸長誘導には一定量のGAが不可欠であると推察した。しかし,非矮性品種にGA生合成阻害剤パクロプトラゾールを処理することで,高温前処理しなかった植物体ではメソコチル伸長が有意に抑制されたのに対して,高温前処理を行った植物体ではメソコチル伸長の抑制はわずかであった。GA関連遺伝子の発現解析したところ,SD1,OsGA3ox2,OsGA2ox3 のGA生合成遺伝子は高温前処理により発現が増大し,GA不活性化関連遺伝子の中には高温前処理区で発現量が低下するものがあった。これらの結果より,高温前処理によるメソコチル伸長誘導には一定量のGAが不可欠であるが,GAの関与のみでは説明できず他の因子が関与する可能性が考えられた。 そこでエチレンとジャスモン酸の関与について調べた。エチレン反応阻害剤で処理することにより,高温前処理によるメソコチル伸長誘導効果の減少が見られた。また,ジャスモン酸生合成関連遺伝子の GAOGAO1 の発現は,日本型品種のメソコチルが短い品種で高発現していたが,高温前処理により発現が低下することがわかった。 高温前処理の実用性について調査した。高温前処理した種子を30℃と4℃で保存したところ少なくとも4ヶ月間はメソコチルの伸長誘導効果は持続し,保存温度による違いは見られなかった。高温前処理は畑状態での深播きに有効であることは以前に示したが,湛水直播においても品種によっては有効であることがわかった。

  • 東 哲司

    学術研究助成基金助成金/基盤研究(C), Apr. 2018 - Mar. 2021, Principal investigator

    Competitive research funding

  • 東 哲司

    科学研究費補助金/基盤研究(C), Apr. 2012 - Mar. 2015, Principal investigator

    Competitive research funding

  • 伊藤 一幸

    学術研究助成基金助成金/挑戦的萌芽研究, Apr. 2013 - Mar. 2014

    Competitive research funding

  • Analysis of high photosynthetic function and high-yielding ability of backcross lines derived from Oryza sativa and wild rice species, O.rufipogon

    UCHIDA Naotsugu, SUGIMOTO Toshio, ISHII Takashige, AZUMA Tetsushi

    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 2001 - 2004

    The present study was carried out to get some information for using wild rice species to improve leaf photosynthesis and grain yield. We examined photosynthetic rates and properties of dry matter production in BC2F1-BC2F4 lines. In BC2F1 populations, several lines had significantly higher photosynthetic rates (OER) than parental cultivars, and 14-25% of plants in the populations had higher OERs than the highest values in parental cultivars. These higher OERs showed positive correlation with the contents of Rubisco and/or Rubisco activase. Four lines of BC2F4 were generated by backcrossing wild rice with cultivar Nipponbare. The photosynthetic rates under saturated light and ambient air conditions in these 4 lines were average 7% higher than Nipponbare. Also, the grain yield per plant of BC2F4 lines were average 16% higher These results suggest that O.rufipogon can be used as a source of germplasm to improve the photosynthetic capacity and grain yield of O.sativa. In order to identify useful QTL alleles from wild rice relatives, we backcrossed with two typical rice cultivars, japonica Nipponbare and indica IR36. In the BC2 generation, several characters including photosynthetic activity were evaluated, and single-point QTL analysis was carried out using 74 microsatellite markers. From these analysis, two wild QTL alleles increasing photosynthetic activity was detected. The present results suggest that the wild QTL alleles are very useful in improving photosynthetic function and yield of rice.

  • 浮稲節間のジベレリンによる細胞伸長と細胞壁合成の関係

    東 哲司

    日本学術振興会, 科学研究費助成事業, 奨励研究(A), 神戸大学, 1999 - 2000

    UDP-糖を可逆的に結合する能力がありゴルジ体膜に存在することよりヘミセルロース性多糖の合成に関与している可能性が示唆されているReversibly Glycosylated Polypeptide(RGP)と細胞伸長との関係を明らかにするため,ジベレリン処理により節間の急激な伸長能力を示す浮稲茎切片を実験材料に用いて研究を行い,以下の結果が得られた. 1 アラビドプシスから得られたRGP抗体を用いて,イネ節間中の伸長に伴うRGPタンパク量の変化を調べた.イネ節間中の可溶性タンパク質および膜タンパク質中のRGPのレベルは,節間の急速な伸長をもたらす浸水およびジベレリン処理によりほとんど変動しなかった.現在イネRGPタンパク質の抗体を作成中であり,これを用いて再調査する予定である. 2 イネRGP遺伝子(OsRGP)をクローニングした結果,イネにおいて二つのRGP遺伝子(OsRGP1,OsRGP2)が得られ,エンドウRGP(PsRGP1)との比較でOsRGP1では86%,OsRGP2では43%の相同性(アミノ酸レベル)が認められた. 3 OsRGP1の遺伝子特異的配列をプローブとして,この遺伝子の様々な器官での発現量を調べた.この遺伝子は,成長中の節間・幼葉鞘・根端で発現しており,節間では細胞の分裂組織と伸長部位で高い発現量が認められた.浮稲茎切片をジベレリン処理すると,処理8時間以降にOsRGP1のmRNAの蓄積が節間基部において認められた.以上の結果ならびに昨年度得られた結果より,OsRGP1遺伝子の発現は,イネの様々な器官の生長と相関があり,ジベレリンによって伸長が促進される節間組織での増大する細胞壁合成と関係があることが考えられる.

  • response to high-salt stress in Halophyte cells

    YASUDA Takeshi, AZUMA Tetsushi, UCHIDA Naotsugu

    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kobe University, 1997 - 1998

    Halophyte plants are able to grow under high saline environments. For examining cellular response of Halophyte cells to salt stress, cultured cells from 3 Atriplex species ; 1 entiformis (AL), halimus (AH) and halimus (AH) were treated with and without 0.2M NaCl, and polypeptide patterns were analyzed by 2-D electrophoresis. Significant increase of polypeptide spot were detected in insoluble protein fractions of salt treated Atriplex cells on NEPHGE/SDS electrophoresis. A polypeptide named SP1 was with a molecular mass of 27 kDa with pI over 8.5. The polypeptide was glycoprotein with Con A binding activity. Eluted proteins from electrophoretic spot of LH were used for antibody preparation by mice and N-terminal amino acid sequencing. mRNA were isolated from salt-treated LH cells and cDNA library was prepared, and library screening were done using a probe, which amplified by PCR on primers constructed from N-terminal amino-acid sequences. We have determined the nucleotide sequence of a full length cDNA for SP1 and submitted on the DDBJ/EMBL/GenBank databases (AB024338). Reduced amino acid sequences reveals that SP1 is 224-AA, 24 kDa and pI=9.72. A search of the GenBank data base for SP1 amino acid sequence showed similarity to Germin and oxalate-oxidase.

  • Activation Mechanisms in Rice Photosynthesis

    UCHIDA Naotsugu, AZUMA Tetsushi, YASUDA Takeshi

    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1994 - 1995

    We investigated the activation mechanisms of rice photosynthesis in relation to Rubisco activase. (1) We purified Rubisco activase from rice leaves, and showed the existence of this enzyme in rice leaves. (2) The amounts of Rubisco activase and Rubisco, and several photosynthetic characteristics in rice plants grown under different nitrogen concentrations and light intensities were investigated. The amounts of Rubisco activase increased linearly with increasing nitrogen supply regardless of the growing light conditions, whereas that of Rubisco increased slightly under the shade condition. The amount of Rubisco activase was almost linearly correlated to the maximum rate of photosynthetic oxygen evolution and the carboxylation efficiency, an indicator of in vivo Rubisco activity. (3) Photosynthetic activity (OER) and the amounts of leaf constituents were investigated in a rice leaf in relation to its aging. The changing pattern of Rubisco activase content was most remarkable among the leaf constituents examined. The OER depended linearly on the Rubisco content below the value of 3 g m^<-2>, but tended to saturate above this value. On the contrary, the amount of Rubisco activase and the OER were linearly correlated during the life span of the leaf. Therefore, the in vivo Rubisco activity can be restricted by Rubisco activase content.

  • 浮稲における光合成産物の動態と伸長の調節機構

    山口 禎, 東 哲司, 内田 直次, 安田 武司

    日本学術振興会, 科学研究費助成事業, 一般研究(C), 神戸大学, 1993 - 1993

    浮稲は主として節間を伸長させることで深水に対応している.この急激な節間伸長の開始と同時に,光合成産物のシンクとソースのバランスを個体の生長に有利になるように変化させていくことが必要になる.本研究では,深水下における同化産物の転流と分配のの変化を明らかにするため,特定の葉に供与した安定同位体炭素の部位別の経時的変化と数種の転流関連の酵素活性を調べた.また,浮稲の節間伸長の機構を探る目的で,明暗両条件下での深水による節間空隙内のガス組成の変化を調べた. 5時間の同化期間中にラベルされた炭素は供与した葉と最上位の伸長中の葉に最も多く分布するが,深水下の24時間後には伸長し始めた最上位の節間部に多く分配された.また,これらの部位のシュクロース/デンプン比が深水下で大きくなり,葉のシュクロースホスフェイトシンターゼ活性と伸長中の節間を含む茎部のシュクロースシンターゼ活性も深水により増加した.これらの結果から,深水下の浮稲において,シンクである伸長中の節間の同化産物の要求量が高まると同時にソースである葉身のシュクロース形成率が高くなり,同化産物の転流が増大するものと考えられた. 浮稲茎切片を用いて明暗両条件下で深水処理した結果,明条件下では節間伸長するが暗条件下では伸長しなかった.明条件下では酸素と二酸化炭素濃度はほとんど変化せず,エチレン濃度は顕著に上昇した.暗条件下では酸素濃度が低下し,二酸化炭素とエチレン濃度は上昇した.また,暗条件下で酸素を供給すると節間の伸長が認められた.以上の結果から,従来から考えられてきた節間空隙内のエチレン濃度の上昇に酸素濃度の低下は必要なく,むしろ旺盛な節間伸長には多量の酸素の供給が不可欠であることを明らかにした.

  • Micropropagation by Somatic Embryogenesis of Coffea Species and Cryopreservation

    YASUDA Takeshi, YAMAGUCHI Tadashi, AZUMA Tetsushi, UCHIDA Naotugu

    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1992 - 1993

    The embryogenic callus and somatic embryo of Coffea arabica and C.canephora can be induced by cytokinin alone from the section of young leaf of mature trees. The cytokinin induced callus has a high embryogenic potetial and is very useful for clonal propagation. As cytokinin, 2-isopentenyl-adenine(2iP)is the best, and benzyladenin(BA), zeatin and kinetin also are effective for somatic embryogenesis from coffee leaf slices. Additional auxins act inhibitory effect on somatic embryogenesis. Protoplast were prepared from embryogenic calluses from C.arabica and canephora and cultured on Gelrite medium with cytokinin as a plant regulator. Somatic embryos were regenerated from protoplasts. These simplified method for preparation and culture of protoplasts is very useful for cell fusion and genetic engeering. Somatic embryos of Coffea were successfully cryopreserved after being exposed to a series of preparative steps ; precultured on media with increasing concentration of sucrose, encapsulated in alginate beads, dehydrated up to 30% and pluged into liquid nitrogen.