Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Eiji Nitasaka Last modified date:2023.11.27

Associate Professor / Information biology / Department of Biology / Faculty of Sciences


Papers
1. Ayaka Shimoki, Satoru Tsugawa, Keiichiro Ohashi, Masahito Toda, Akiteru Maeno, Tomoaki Sakamoto, Seisuke Kimura, Takashi Nobusawa, Mika Nagao, Eiji Nitasaka, Taku Demura, Kiyotaka Okada & Seiji Takeda , Reduction in organ–organ friction is critical for corolla elongation in morning glory, Communications Biology, https://doi.org/10.2525/shita.31.216, 4, 285, 2021.03, In complex structures such as flowers, organ–organ interactions are critical for morphogenesis. The corolla plays a central role in attracting pollinators: thus, its proper development is important in nature, agriculture, and horticulture. Although the intraorgan mechanism of corolla development has been studied, the importance of organ–organ interactions during development remains unknown. Here, using corolla mutants of morning glory described approximately 200 years ago, we show that glandular secretory trichomes (GSTs) regulate floral organ interactions needed for corolla morphogenesis. Defects in GST development in perianth organs result in folding of the corolla tube, and release of mechanical stress by sepal removal restores corolla elongation. Computational modeling shows that the folding occurs because of buckling caused by mechanical stress from friction at the distal side of the corolla. Our results suggest a novel function of GSTs in regulating the physical interaction of floral organs for macroscopic morphogenesis of the corolla..
2. Shuzo Iwanishi, Shohei Zaitsu, Hiroki Shibata, Eiji Nitasaka, An albino mutant of the Japanese rat snake (Elaphe climacophora) carries a nonsense mutation in the tyrosinase gene, Genes and Genetic Systems, 10.1266/ggs.18-00021, 93, 4, 163-167, 2018.01, The Japanese rat snake (Elaphe climacophora) is a common species in Japan and is widely distributed across the Japanese islands. An albino mutant of the Japanese rat snake (“pet trade” albino) has been bred and traded by hobbyists for around two decades because of its remarkable light-yellowish coloration with red eyes, attributable to a lack of melanin. Another albino Japanese rat snake mutant found in a natural population of the Japanese rat snake at high frequency in Iwakuni City, Yamaguchi Prefecture is known as “Iwakuni no Shirohebi”. It has been conserved by the government as a natural monument. The Iwakuni albino also lacks melanin, having light-yellowish body coloration and red eyes. Albino mutants of several organisms have been studied, and mutation of the tyrosinase gene (TYR) is responsible for this phenotype. By determining the sequence of the TYR coding region of the pet trade albino, we identified a nonsense mutation in the second exon. Furthermore, RT-PCR revealed that TYR transcripts were not detected in this snake. These findings suggest that mutation of TYR is responsible for the albino phenotype of the pet trade line of the Japanese rat snake. However, the Iwakuni albino did not share this TYR mutation; thus, these two albino lines differ in their origins..
3. Kyeung Il Park, Eiji Nitasaka, Atsushi Hoshino, Anthocyanin mutants of japanese and common morning glories exhibit normal proanthocyanidin accumulation in seed coats, Plant Biotechnology, 10.5511/plantbiotechnology.18.0613a, 35, 3, 259-266, 2018.01, Anthocyanin and proanthocyanidin biosynthesis pathways are believed to overlap. This study examined proanthocyanidin accumulation in seed coats of morning glories (Ipomoea nil and I. purpurea) carrying mutations in CHS-D, CHI, and ANS genes encoding chalcone synthase, chalcone isomerase, and anthocyanidin synthase, respectively. Chemical staining revealed that mutants accumulate proanthocyanidin normally. Thus, the tested genes are not essential to proanthocyanidin biosynthesis, but are essential to anthocyanin biosynthesis in flowers and stems. Based on the results and the I. nil draft genome sequence, the genes involved in proanthocyanidin biosynthesis, including a new copy of the flavanone 3-hydroxylase gene could be predicted. Moreover, the genome has no homologs for known enzymes involved in producing flavan-3-ols, the starter and extension units of proanthocyanidin. These results suggested that I. nil produces flavan-3-ols through an undiscovered biosynthesis pathway. To characterize proanthocyanidin pigmentation further, we conducted mutant screening using a large I. nil population. We discovered that the brown mutant lines (exhibiting brown seeds and normal anthocyanin pigmentation) do not accumulate proanthocyanidin in their seed coats. Thus, the brown mutation should be useful for further investigations into the various mechanisms controlling anthocyanin and proanthocyanidin pathways..
4. Hiroki Shibata, Shuichi Sakata, Yuzo Hirano, Eiji Nitasaka, Ai Sakabe, Facultative parthenogenesis validated by DNA analyses in the green anaconda (Eunectes murinus), PLoS One, 10.1371/journal.pone.0189654, 12, 12, 2017.12, In reptiles, the mode of reproduction is typically sexual. However, facultative parthenogenesis occurs in some Squamata, such as Komodo dragon (Varanus komodoensis) and Burmese python (Python bivittatus). Here, we report facultative parthenogenesis in the green anaconda (Eunectes murinus). We found two fully developed female neonates and 17 undeveloped eggs in the oviduct of a female anaconda isolated from other individuals for eight years and two months at Ueno Zoo, Japan. To clarify the zygosity of the neonates, we analyzed 18 microsatellite markers of which 16 were informative. We observed only maternal alleles and no paternal alleles for all 16 markers. To examine the possibility of the long-term sperm storage, we estimated allele frequencies in a putative parental stock by genotyping five unrelated founders. If all founders, including the mother, are originated from a single Mendelian population, then the probability that the neonates were produced by sexual reproduction with an unrelated male via long-term sperm storage was infinitesimally small (2.31E-32 per clutch). We also examined samples from two additional offspring that the mother delivered eight years before her death. We consistently observed paternal alleles in these elder offspring, indicating that the mother had switched from sexual reproduction to asexual reproduction during the eight years of isolation. This is the first case of parthenogenesis in Eunectes to be validated by DNA analysis, and suggests that facultative parthenogenesis is widespread in the Boidae..
5. Atsushi Hoshino, Vasanthan Jayakumar, Eiji Nitasaka, Atsushi Toyoda, Hideki Noguchi, Takehiko Itoh, Tadasu Shin, Yohei Minakuchi, Yuki Koda, Atsushi J. Nagano, Masaki Yasugi, Mie N. Honjo, Hiroshi Kudoh, Motoaki Seki, Asako Kamiya, Toshiyuki Shiraki, Piero Carninci, Erika Asamizu, Hiroyo Nishide, Sachiko Tanaka, Kyeung Il Park, Yasumasa Morita, Kohei Yokoyama, Ikuo Uchiyama, Yoshikazu Tanaka, Satoshi Tabata, Kazuo Shinozaki, Yoshihide Hayashizaki, Yuji Kohara, Yutaka Suzuki, Sumio Sugano, Asao Fujiyama, Shigeru Iida, Yasubumi Sakakibara, Genome sequence and analysis of the Japanese morning glory Ipomoea nil, Nature communications, 10.1038/ncomms13295, 7, 2016.11, Ipomoea is the largest genus in the family Convolvulaceae. Ipomoea nil (Japanese morning glory) has been utilized as a model plant to study the genetic basis of floricultural traits, with over 1,500 mutant lines. In the present study, we have utilized second- and third-generation-sequencing platforms, and have reported a draft genome of I. nil with a scaffold N50 of 2.88 Mb (contig N50 of 1.87 Mb), covering 98% of the 750 Mb genome. Scaffolds covering 91.42% of the assembly are anchored to 15 pseudo-chromosomes. The draft genome has enabled the identification and cataloguing of the Tpn1 family transposons, known as the major mutagen of I. nil, and analysing the dwarf gene, CONTRACTED, located on the genetic map published in 1956. Comparative genomics has suggested that a whole genome duplication in Convolvulaceae, distinct from the recent Solanaceae event, has occurred after the divergence of the two sister families..
6. 石黒 弘樹, 仁田坂 英二, 大谷 基泰, An efficient plant regeneration through embryogenic callus formation and direct somatic embryogenesis via immature embryo culture in Ipomoea purpurea and I. tricolor., Plant Biotechnology, 31, 179-183, 2014.08.
7. 森田 裕将, 仁田坂 英二, A chalcone isomerase-like protein enhances flavonoid production and flower pigmentation., Plant J., 10.1111/tpj.12469, 29, 2014.02.
8. Hiroki Ishikuro, Eiji Nitasaka, Motoyasu Otani, An efficient plant regeneration through embryogenic callus formation and direct somatic embryogenesis via immature embryo culture in Ipomoea purpurea and I. tricolor, Plant Biotechnology, 10.5511/plantbiotechnology.14.0216a, 31, 2, 179-183, 2014.01, We established an efficient plant regeneration system to form embryogenic calli in common morning glory (Ipomoea purpurea) and blue morning glory (I. tricolor). Immature embryos of both morning glories cultured on media containing 1 mg l-1 4-fluorophenoxyacetic acid (4FA) and 6% sucrose formed many embryogenic calli. The frequency of embryogenic callus formation was highest in I. purpurea strain Q74 (42.5%) and in I. tricolor cultivar 'Flying Saucers' (36.7%). Embryogenic callus formation differed with the genotypes in both morning glories. Numerous somatic embryos were formed from the embryogenic calli when the calli were transferred onto plant growth regulator-free medium..
9. 小野道之, 仁田坂 英二, Molphological changes in Ipomoea nil using chimeric repressors of Arabidopsis TCP3 and TCP5., Plant biotech. , 29, 457-463, 2013.01.
10. Michiyuki Ono, Satomi Hiyama, Yohei Higuchi, Hiroshi Kamada, Eiji Nitasaka, Tomotsugu Koyama, Nobutaka Mitsuda, Masaru Ohme-Takagi, Kimiyo Sage-Ono, Morphological changes in Ipomoea nil using chimeric repressors of Arabidopsis TCP3 and TCP5, Plant Biotechnology, 10.5511/plantbiotechnology.12.1010a, 29, 5, 457-463, 2012.12, Chimeric REpressor gene-Silencing Technology (CRES-T) is a reverse genetic method that converts transcriptional factors (TFs) to chimeric repressors by fusion with an ethylene-responsive element-binding factor (ERF)- associated amphiphilic repression domain. The plant expressing chimeric repressor is expected to show loss-of-function phenotype of the original TF even in the presence of other functionally redundant TFs. We used the CRES-T system for modification of flower shape in transgenic Ipomoea nil (formally Pharbitis nil). I. nil is emerging as a model plant for ornamental flowers because it has produced a wide variety of historical mutants, and it has been chosen to be a part of the National BioResource Project in Japan. We used cDNAs of TFs of Arabidopsis thaliana with the CRES-T system because A. thaliana TFs are well characterized compared with I. nil TFs. For this study, we selected two TCP (TEOSINTE BRANCHED1, CYCLOIDEA, and PCF) TFs, TCP3 and TCP5, because overexpression of these chimeric repressors TCP3SRDX and TCP5SRDX causes severe morphological alterations in A. thaliana. We found that these chimeric repressors cause morphological alterations, an undeveloped corolla and wavy petals in I. nil. In addition, the sympetalous corolla was easily disrupted to form choripetalous corolla. Although several TCP3SRDX transgenic ornamental flowers were reported, typical sympetalous flowers like I. nil have not yet been presented..
11. 久保山勉, 仁田坂 英二, Development of EST-SSR markers of Ipomoea nil., Breed Sci., 62, 99-104, 2012.05.
12. Tong Ly, Hiroyuki Fukuoka, Asami Otaka, Atsushi Hoshino, Shigeru Iida, Eiji Nitasaka, Nobuyoshi Watanabe, Tsutomu Kuboyama, Development of EST-SSR markers of Ipomoea nil, Breeding Science, 10.1270/jsbbs.62.99, 62, 1, 99-104, 2012.03, Although Japanese morning glory (Ipomoea nil (L.) Roth.) has been used intensively for genetic studies, DNA markers have not been developed in Ipomoea nil sufficient to cover all chromosomes. Therefore, we conducted microsatellite (simple sequence repeats, SSR) marker development in I. nil for future genetic studies. From 92,662 expressed sequence tag (EST) sequences, 514 unique microsatellite-containing ESTs were identified. Primer pairs were designed automatically in 326 SSRs. Of 150 SSRs examined, 75 showed polymorphisms among strains. A phenogram based on the SSR genotypes revealed the genetic relation among seven Japanese morning glories from five different regions of the world and an ivyleaf morning glory (I. hederacea Jacq.). The developed SSR markers might be applicable for genetic studies of morning glories and their relatives..
13. Kurata N, Satoh H, Kitano H, Nagato Y, Endo T, Sato K, Akashi R, Ezura H, Kusaba M, Kobayashi M, Nitasaka E, Kasai F, Yamazaki Y and Yoshimura A, NBRP, National Bioresource Project of Japan and Plant Bioresource Management., Breed. Sci., 60, 2010.12.
14. Nori Kurata, Hikaru Satoh, Hidemi Kitano, Yasuo Nagato, Takashi Endo, Kazuhiro Sato, Ryo Akashi, Hiroshi Ezura, Makoto Kusaba, Masatomo Kobayashi, Eiji Nitasaka, Fumie Kasai, Yukiko Yamazaki, Atsushi Yoshimura, NBRP, national bioresource project of Japan and plant bioresource management, Breeding Science, 10.1270/jsbbs.60.461, 60, 5, 461-468, 2010.12, The National BioResource Project has been organized and established to promote research activities using valuable bioresources. A total of twenty-eight bioresources for ten animals, nine plants and nine microorganisms/ cell lines developed or collected in Japan were selected for the project. Resources are categorized into several different groups in the project; genetic resources, germplasm, genome resources and their information. Choices of how many resources must be preserved and maintained and in which categories are dependent on the status of the research community of each organism. These resources, if utilized systematically and intelligently, are powerful means for leading new scientific discoveries. Some examples can be seen in this paper. This paper reviews plant bioresources with the main focus on rice resource activities within the project..
15. Yamazaki Y et al. 他32名、21番目, NBRP databases: Databases of biological resources in Japan., Nucleic Acids Res., 38, 26-32, 2010.05.
16. Yukiko Yamazaki, Ryo Akashi, Yutaka Banno, Takashi Endo, Hiroshi Ezura, Kaoru Fukami-Kobayashi, Kazuo Inaba, Tadashi Isa, Katsuhiko Kamei, Fumie Kasai, Masatomo Kobayashi, Nori Kurata, Makoto Kusaba, Tetsuro Matuzawa, Shohei Mitani, Taro Nakamura, Yukio Nakamura, Norio Nakatsuji, Kiyoshi Naruse, Hironori Niki, Eiji Nitasaka, Yuichi Obata, Hitoshi Okamoto, Moriya Okuma, Kazuhiro Sato, Tadao Serikawa, Toshihiko Shiroishi, Hideaki Sugawara, Hideko Urushibara, Masatoshi Yamamoto, Yoshio Yaoita, Atsushi Yoshiki, Yuji Kohara, NBRP databases
Databases of biological resources in Japan, Nucleic Acids Research, 10.1093/nar/gkp996, 38, SUPPL.1, 2009.11, The National BioResource Project (NBRP) is a Japanese project that aims to establish a system for collecting, preserving and providing bioresources for use as experimental materials for life science research. It is promoted by 27 core resource facilities, each concerned with a particular group of organisms, and by one information center. The NBRP database is a product of this project. Thirty databases and an integrated database-retrieval system (BioResource World: BRW) have been created and made available through the NBRP home page (http://www.nbrp.jp). The 30 independent databases have individual features which directly reflect the data maintained by each resource facility. The BRW is designed for users who need to search across several resources without moving from one database to another. BRW provides access to a collection of 4.5-million records on bioresources including wild species, inbred lines, mutants, genetically engineered lines, DNA clones and so on. BRW supports summary browsing, keyword searching, and searching by DNA sequences or gene ontology. The results of searches provide links to online requests for distribution of research materials. A circulation system allows users to submit details of papers published on research conducted using NBRP resources..
17. Nitasaka E, Morphological mutants induced by transposable elements in the Japanese morning glory., Gamma Field Symposia, 46, 73-78, 2009.04.
18. Kitazawa D, Miyazawa Y, Fujii N, Hoshino A, Iida S, Nitasaka E, *Takahashi H, The gravity-regulated growth of axillary buds is mediated by a mechanism different from decapitation-induced release, Plant Cel Physiol., 49, 891-900, 2008.12.
19. Kitazawa E, Miyazawa Y, Fujii N, Nitasaka E and *Takahashi H, Characterization of a novel gravitropic mutant of morning glory, weeping2, Adv. Space Res., 42, 1050-1059., 2008.12.
20. Daisuke Kitazawa, Yutaka Miyazawa, Nobuharu Fujii, Eiji Nitasaka, Hideyuki Takahashi, Characterization of a novel gravitropic mutant of morning glory, weeping2, Advances in Space Research, 10.1016/j.asr.2007.10.029, 42, 6, 1050-1059, 2008.09, In higher plants, gravity is a major environmental cue that governs growth orientation, a phenomenon termed gravitropism. It has been suggested that gravity also affects other aspects of morphogenesis, such as circumnutation and winding movements. Previously, we showed that these aspects of plant growth morphology require amyloplast sedimentation inside gravisensing endodermal cells. However, the molecular mechanism of the graviresponse and its relationship to circumnutation and winding remains obscure. Here, we have characterized a novel shoot gravitropic mutant of morning glory, weeping2 (we2). In the we2 mutant, the gravitropic response of the stem was absent, and hypocotyls exhibited a severely reduced gravitropic response, whereas roots showed normal gravitropism. In agreement with our previous studies, we found that we2 mutant has defects in shoot circumnutation and winding. Histological analysis showed that we2 mutant forms abnormal endodermal cells. We identified a mutation in the morning glory homolog of SHORT-ROOT (PnSHR1) that was genetically linked to the agravitropic phenotype of we2 mutant, and which may underlie the abnormal differentiation of endodermal cells in this plant. These results suggest that the phenotype of we2 mutant is due to a mutation of PnSHR1, and that PnSHR1 regulates gravimorphogenesis, including circumnutation and winding movements, in morning glory..
21. Daisuke Kitazawa, Yutaka Miyazawa, Nobuharu Fujii, Atsushi Hoshino, Shigeru Iida, Eiji Nitasaka, Hideyuki Takahashi, The gravity-regulated growth of axillary buds is mediated by a mechanism different from decapitation-induced release, Plant and Cell Physiology, 10.1093/pcp/pcn063, 49, 6, 891-900, 2008.06, When the upper part of the main shoot of the Japanese morning glory (Pharbitis nil or Ipomoea nil) is bent down, the axillary bud situated on the uppermost node of the bending region is released from apical dominance and elongates. Here, we demonstrate that this release of axillary buds from apical dominance is gravity regulated. We utilized two agravitropic mutants of morning glory defective in gravisensing cell differentiation, weeping (we) and weeping2 (we2). Bending the main shoots of either we or we2 plants resulted in minimal elongation of their axillary buds. This aberration was genetically linked to the agravitropism phenotype of the mutants, which implied that shoot bending-induced release from apical dominance required gravisensing cells. Previous studies have shown that basipetal translocation of auxin from the apical bud inhibits axillary bud growth, whereas cytokinin promotes axillary bud outgrowth. We therefore compared the roles of auxin and cytokinin in bending- or decapitation-induced axillary bud growth. In the wild-type and we plants, decapitation increased cytokinin levels and reduced auxin response. In contrast, shoot bending did not cause significant changes in either cytokinin level or auxin response, suggesting that the mechanisms underlying gravity- and decapitation-regulated release from apical dominance are distinct and unique..
22. Eiji Nitasaka, Morning glory mutants induced by transposable elements in the Edo era, Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 52, 15, 1959-1964, 2007.12.
23. Mayumi Iwasaki, Eiji Nitasaka, The FEATHERED gene is required for polarity establishment in lateral organs especially flowers of the Japanese morning glory (Ipomoea nil ), Plant Molecular Biology, 10.1007/s11103-006-9066-2, 62, 6, 913-925, 2006.12, Most strains harboring the feathered (fe) mutation in the Japanese morning glory (Ipomoea nil or Pharbitis nil) show deformed phenotypes such as upcurled leaves and separated or tubular petals. These phenotypes seem to be caused by loss of abaxial identity in lateral organs. The FE gene was isolated using the inserted transposon as a tag. An En/Spm-related transposable element, Tpn102, inserted in the fourth intron of the FE gene, was responsible for the fe mutation. FE encodes a GARP transcription factor closely related to Arabidopsis KANADI1 (KAN1), which promotes an abaxial cell fate. Genetic analyses and molecular studies, which showed that all fe mutant strains have the same fe allele despite their phenotypic differences, revealed that fe strains with strong phenotypes have additional mutations enhancing the fe phenotype. These findings and historical records of fe phenotypes suggest that these enhancer mutations were accumulated in the fe background during selection for strong phenotypes. The mutant phenotypes and molecular analysis of fe strains suggest that FE regulates the abaxial identity of lateral organs redundantly with modifier genes, as KAN1 does in Arabidopsis. FE, however, affects flower phenotype even in the single mutant unlike KAN1, moreover, modifier mutations affect flower phenotype only in the fe mutant background, suggesting that FE may play a more crucial role in promotion of abaxial cell fate in flowers of the Japanese morning glory..
24. Morita Y, Saitoh M, Hoshino A, Nitasaka E and Iida S, solation of cDNAs for R2R3-MYB, bHLH, and WDR transcriptional regulators and identification of c and ca mutations conferring white flowers in the Japanese morning glory., Plant Cell Physiol., 47: 457-470, 2006.01.
25. Harada K, Okaura T, Giang le H, Van Huan N, Iwasaki M, Nitasaka E., A novel microsatellite locus isolated from an AFLP fragment in the mangrove species Kandelia obovata, J Plant Res., 10.1007/s10265-004-0187-x, 118, 1, 49-51, 118: 49-51, 2005.01.
26. Cho KH, Shindo T, Kim GT, Nitasaka E, Tsukaya H, Characterization of a member of the AN subfamily, IAN, from Ipomoea nil, Plant Cell Physiol., 10.1093/pcp/pci020, 46, 1, 250-255, 46: 250-255, 2005.01.
27. Morita Y, Hoshino A, Kikuchi Y, Okuhara H, Ono E, Tanaka Y, Fukui Y, Saito N, Nitasaka E, Noguchi H, Iida S, Japanese morning glory dusky mutants displaying reddish-brown or purplish-gray flowers are deficient in a novel glycosylation enzyme for anthocyanin biosynthesis, UDP-glucose:anthocyanidin 3-O-glucoside-2''-O-glucosyltransferase, due to 4-bp insertions in the gene., Plant J., 10.1111/j.1365-313X.2005.02383.x, 42, 3, 353-363, 42: 353-363, 2005.01.
28. Kawasaki S, Nitasaka E., Characterization of Tpn1 family in the Japanese morning glory: En/Spm-related transposable elements capturing host genes, Plant Cell Physiol., 10.1093/pcp/pch109, 45, 7, 933-944, vol 45, 933-944, 2004.01.
29. Suzuki Y, Saso K, Fujioka S, Yoshida S, Nitasaka E, Nagata S, Nagasawa H, Takatsuto S, Yamaguchi I, A dwarf mutant strain of Pharbitis nil, Uzukobito (kobito), has defective brassinosteroid biosynthesis, Plant J., 10.1046/j.1365-313X.2003.01887.x, 36, 3, 401-410, Vol 36, 401-410, 2003.10.
30. Eiji Nitasaka, Insertion of an En/Spm-related transposable element into a floral homeotic gene DUPLICATED causes a double flower phenotype in the Japanese morning glory, Plant J., 10.1046/j.1365-313X.2003.01896.x, 36, 4, 522-531, Vol 36, 522-531, 2003.11.
31. Kim H N, Nitasaka E, Odrzykoski I J, Yamazaki T, The psbA sequence diversity in the liverwort Conocephalum conicum (Conocephalaceae), Gen. Genet. Sys., Vol 76, 279-288, 2001.01.
32. Shiraiwa T, Nitasaka E, Yamazaki T, geko, a novel gene involved in olfaction in Drosophila melanogaster, J. Neurogenet., 10.3109/01677060009083480, 14, 3, 145-+, Vol 14, 145-164, 2000.01.