Plant Biotechnology
Online ISSN : 1347-6114
Print ISSN : 1342-4580
ISSN-L : 1342-4580
21 巻, 5 号
選択された号の論文の15件中1~15を表示しています
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Review
Original Papers
  • Ikumi Watase, Hiroshi Sudo, Mami Yamazaki, Kazuki Saito
    2004 年 21 巻 5 号 p. 337-342
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    Camptothecin derivatives are clinically used as anti-tumor alkaloids that are currently obtained by extraction from intact plants. Seeking for the alternative sources for commercial production and for fundamental study, cell and tissue cultures have been investigated. In the present study, we developed a method for regeneration of Ophiorrhiza pumila plant from hairy roots transformed with Agrobacterium rhizogenes. The regeneration frequency was over 83%. Integration of a rol B gene from T-DNA of A. rhizogenes was confirmed by polymerase chain reaction in both of the hairy roots and the regenerated plants. The transformed plants accumulated camptothecin in amounts of 66–111% compared with that in the wild-type plants.
  • Shigeyuki Nagashima, Satoko Tomo, Yutaka Orihara, Takafumi Yoshikawa
    2004 年 21 巻 5 号 p. 343-348
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    The Eucalyptus perriniana cultured cells are widely used to biotransform a variety of compounds. The glucosyltransferase activity of a crude protein extract of E. perriniana cultured cells was maximized when cell growth was in the pre-logarithmic to logarithmic phase. We cloned a cDNA encoding glucosyltransferase (EPGT) from E. perriniana cultured cells by RT-PCR using a degenerated primer and RACE-PCR. The cDNA contained an open reading frame encoding 467 amino acids with a calculated molecular mass of 51.6 kDa. The consensus sequence of the plant glucosyltransferases was included in the deduced amino acid sequence. The amino acid sequence of EPGT showed a high identity to glucosyltransferases from tobacco and petunia. The recombinant EPGT was expressed in Escherichia coli and its substrate specificity was examined using UDP-[U-14C] glucose. Cinnamic acid was the best sugar acceptor in the compounds tested.
  • Masataka Kajikawa, Katsuyuki T. Yamato, Yoshito Kohzu, Ryoko Sakata, H ...
    2004 年 21 巻 5 号 p. 349-353
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    We report generation of 9,301 expressed sequence tags (ESTs) derived from callus cells of Euphorbia tirucalli in search of candidate genes involved in the triterpenoid and sterol biosyntheses. After assembling 4,342 redundant ESTs into 1,252 clusters, a total of 6,211 non-redundant sequences were obtained. Database search revealed that 4,449 out of the 6,211 sequences shared significant similarities to known nucleotide or amino acid sequences, while the remaining 1,762 showed no significant matches and appear to represent novel genes in E. tirucalli. The annotations assigned to the hit database entries suggest that 48 of the unique sequences are involved in triterpenoid and sterol biosyntheses. Although functions of genes tagged by the 48 sequences are yet to be determined, the EST resource described here should contribute to identification of genes participating in the triterpenoid and sterol biosyntheses in E. tirucalli.
  • Hirobumi Yamamoto, Hiroki Kuribayashi, Yasuharu Seshima, Ping Zhao, Is ...
    2004 年 21 巻 5 号 p. 355-359
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    Cultured cells of Sophora flavescens produce (2S)-naringenin-derived prenylated flavanone sophoraflavanone G and liquiritigenin-derived trifolirhizin 6′-O-malonate. The regulation of flavonoid biosynthesis was examined by analyzing the metabolites produced in the cultured cells fed (2RS)-naringenin. The amount of sophoraflavanone G in cells fed 0.1 or 0.3 mM (2RS)-naringenin was two-fold that in control cells, although the conversion ratio was only 5 to 10% of the administered (2S)-naringenin. On the other hand, (2R)-naringenin, which does not occur naturally, was efficiently converted into its 4′,7-di-O-β-D-glucoside. (2S)-Naringenin prenylation activity was higher at the logarithmic growth stage. The cells fed (2RS)-naringenin at a lower concentration (below 0.1 mM), accumulated sophoraflavanone G as the main prenylated flavanone. In contrast, cells fed 0.3 mM (2RS)-naringenin accumulated 8-prenylnaringenin and leachianone G, intermediates of sophoraflavanone G in large amounts. Accumulation of trifolirhizin 6′-O-malonate was suppressed by the addition of naringenin.
  • Noboru Hiraoka, Indra Dutt Bhatt, Yuko Sakurai, Jung-In Chang
    2004 年 21 巻 5 号 p. 361-366
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    Somatic embryos of Corydalis ambigua (Papaveraceae), which were cultured in liquid Linsmaier and Skoog medium supplemented with 0.1 µM IAA and 3% sucrose, produced two tetrahydroprotoberberine alkaloids, corydaline (0.03% of dry cell weight) and cavidine (1.09%). Among various plant growth regulators tested, two phenylurea derivatives, thidiazuron and N-(2-chloro-4-pyridyl)-N′-phenylurea enhanced the alkaloid production. Addition of 1 µM thidiazuron to the medium gave the maximum alkaloid content, 0.12% corydaline and 1.91% cavidine, after 21 days incubation. These results were compared with those from callus cultures and various intact organs. Corydaline and cavidine were accumulated in leaf, tuber and somatic embryos, whereas corybulbine was detected only in tubers. Callus cultures and immature seeds, which lack embryos, contained only trace amounts of these alkaloids, suggesting the necessity for organ differentiation for alkaloid production in C. ambigua.
  • Jun Ogata, Yoshio Itoh, Madoka Ishida, Hiroyuki Yoshida, Yoshihiro Oze ...
    2004 年 21 巻 5 号 p. 367-375
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    Yellow petals of carnations contain chalcone 2′-O-glucoside. The glucosylation occurs after the p-coumaroyl CoA and malonyl-CoA condensation reaction by chalcone synthase (CHS), but the enzyme(s) transferring glucose from UDP-glucose to the 2′-OH position of chalcone has not been identified. The full-length cDNA clones for 18 glucosyltransferase (GT) genes were isolated from petal tissue of carnation (Dianthus caryophyllus) bearing various flower colors. The 18 GTs encoded in the cDNAs were enzymatically characterized in an E. coli expression system using chalcone, flavanone, flavone, flavonol and anthocyanidin as substrates. Three of the 18 were characterized as 3-GT possessing different substrate specificities for flavonoids and anthocyanidin and another two GTs catalyzed the transfer of glucose to the 2′-hydroxyl group of chalcone. In addition, these two enzymes glucosylated flavonol (3-OH and 7-OH), flavanone (7-OH), flavone (7-OH) and anthocyanidin (3-OH and 7-OH).
  • Shinzo Tsuda, Yuko Fukui, Noriko Nakamura, Yukihisa Katsumoto, Keiko Y ...
    2004 年 21 巻 5 号 p. 377-386
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    Petunia flower colors are mainly due to flavonoids. The flower color of commercial varieties of Petunia hybrida was successfully modified by the suppression of endogenous flavonoid biosynthetic genes, the expression of a hetelorogous flavonoid biosynthetic gene, and the combination of both. Flower color changed from purple to almost white or from purple to red by the suppression of the endogenous gene expression, from red to orange by the down-regulation of the flavonoid 3′-hydroxylase gene and the expression of the rose dihydroflavonol 4-reductase gene, and from violet to pale violet by the expression of the flavonol synthase or flavone synthase gene. These results clearly indicate the usefulness of metabolic engineering of the flavonoid biosynthetic pathway to modify flower color. Only a few of the transgenic petunia exhibited phenotypic stability. For commercialisation, it is necessary to generate many independent transgenic lines, select elite lines with stable phenotypes and maintain them in tissue culture.
  • Fumie Betsui, Norie Tanaka-Nishikawa, Koichiro Shimomura
    2004 年 21 巻 5 号 p. 387-391
    発行日: 2004年
    公開日: 2005/06/03
    ジャーナル フリー
    The adventitious roots of Raphanus sativus L. cv. Peking Koushin were established by culturing root segments of in vitro seedlings in 1/2 Murashige and Skoog (MS) liquid medium supplemented with 0.5 mg/l IBA. The adventitious roots cultured in 1/2 MS liquid medium supplemented with 0.5 mg/l IBA produced anthocyanin in the dark. When cultured under the 14 h/day light condition, the adventitious roots cultured with 0.5 mg/l IBA produced more anthocyanin than those cultured with 0.1 or 0.5 mg/l NAA. The acid hydrolysis of the extract prepared from the adventitious roots revealed that the main anthocyanidin was pelargonidin. In addition, the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of the adventitious root extract was comparable to that of roots of the intact plant grown in the field.
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