Plant Biotechnology
Online ISSN : 1347-6114
Print ISSN : 1342-4580
ISSN-L : 1342-4580
Volume 21 , Issue 3
Showing 1-11 articles out of 11 articles from the selected issue
Original Paper
  • Takeshi FUKUMOTO, Tatsuo NAKAMURA, Masashi SUZUKI, Shinjiro OGITA, Tet ...
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 177-182
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    Effects of a wide range of concentrations of four salts (NaCl, KCl, MgCl2, CaCl2) and different pHs (pH 4.5, 5.0, 5.7, 6.2) on colony formation, were investigated in protoplast culture of mangrove, Bruguiera sexangula, suspension cells. The results were compared to those obtained with protoplasts of tobacco BY-2 cells and leaf protoplasts of Populus alba. A 96-multiwell culture plate method was used and only 250 to 2500 protoplasts in 55 μl medium were sufficient to test the effect of each treatment. The effects of four salts were always found to inhibit colony formation of Populus and tobacco protoplasts at pH 5.7. In contrast, MgCl2 and CaCl2 stimulated further development of B. sexangula protoplasts, while KCl had an inhibitory effect. The highest number of colony formation was obtained at pH 5.7 without salt additions. However, at lower pHs, some stimulatory effects were found at low concentrations of all four salts tested. Depending on the pHs, different patterns of stimulation and inhibition of four salts were obtained in B. sexangula protoplasts.
    Download PDF (790K)
  • Xiaoge FENG, Kaoru T. YOSHIDA
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 183-189
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    Phytic acid (myo-inositol hexakisphosphate) is the storage form of phosphorus in plant seeds. Reduction of phytic acid levels in seeds leads to both an increase in the availability of phosphorus and a reduction in the environmental load. Myo-inositol-1-phosphate (Ins(3)P1) synthase (EC 5.5.1.4) catalyzes the first step in phytic acid biosynthesis. We attempted to reduce the phytic acid content of seeds through manipulation of the expression of the Ins(3)P1 synthase gene. A rice Ins(3)P1 synthase gene, RINO1, was transformed into rice plants in the antisense or sense orientation under the control of the CaMV 35S promoter or the RINO1 promoter. Some T1 seeds that transformed both with RINO1 promoter::antisense RINO1 gene and with 35S promoter::sense RINO1 gene increased the amount of inorganic phosphates, as compared to those of non-transgenic plants. This result suggested a molar-equivalent decrease in phytic acid. We also examined RINO1 promoter activity using a β-glucuronidase (GUS) reporter gene. Finally, we discuss the strategy of molecular breeding to reduce phytic acid levels in seeds.
    Download PDF (1664K)
  • Shigeyuki NAGASHIMA, Aya OKAMOTO, Hideyuki SUZUKI, Yoshihisa ASADA, To ...
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 191-195
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    The UDP-galactose: anthocyanin 3-O-galactosyltransferase (ACGaT) cDNA was cloned from cell-suspension cultures of Aralia cordata Thunb. (Araliaceae). The cDNA was isolated from a cDNA library using a galactosyltransferase cDNA from Vigna mungo. The cDNA contained an open reading frame encoding 452 amino acids with a calculated molecular mass of 50.0 kDa. The deduced amino acid sequence of ACGaT cDNA included a plant secondary product glycosyltransferase signature sequence and was similar to the flavonoid 3-O-glycosyltransferases from petunia and grape. The enzymatic activity of the recombinant ACGaT expressed in Escherichia coli was detected toward anthocyanins and flavonols as an aglycon and UDP-galactose as a sugar donor. The reaction product for quercetin and UDP-galactose catalyzed by the recombinant ACGaT was identified as quercetin 3-O-β-galactoside using nuclear magnetic resonance spectroscopy.
    Download PDF (681K)
  • Vijitha R. M. VIDHANAARACHCHI, Shigeyuki BABA, Seiichi MURAYAMA
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 197-203
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    In vitro somatic embryogenesis of Castanopsis cuspidata var. sieboldii was achieved from immature embryo-derived callus and the morphological course of events during embryo development was evaluated by scanning electron microscopy technique (SEM). Embryogenic callus could be initiated from immature embryos and optimum induction of callus was observed on Murashige and Skoog (MS) medium supplemented with 10 μM 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 1 μM benzyl‐aminopurine (BAP). Somatic embryo development was occurred on half-strength basal MS medium supplemented with 2 μM BAP, 0.25 μM naphthaleneacetic acid (NAA). Somatic embryo maturation was accomplished using 1 μM zeatin, 0.25 μM indolebutyric acid (IBA). SEM observations indicated development of an extracellular material at an early stage of differentiation and a course of differentiation leading to development of somatic embryos.
    Download PDF (2787K)
  • Yasuko ITO, Naohito TOKUNAGA, Yasushi SATO, Hiroo FUKUDA
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 205-213
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    In order to understand cell-cell interactions involved in xylem differentiation, we studied intercellular molecules in an in vitro Zinnia xylogenic culture system, where single mesophyll cells transdifferentiate into tracheary elements (TEs) and xylem parenchyma cells. We found that UV-absorbing substances accumulated predominantly in xylogenesis-inducing medium and kept increasing even after the TEs died. This accumulation was inhibited by L-α-aminooxy-β-phenylpropionic acid (AOPP), an inhibitor of phenylalanine ammonia-lyase, and also by brefeldin A, an inhibitor of vesicle transport. These results indicated that living non-TE cells, probably xylem parenchyma cells, secrete some kinds of phenylpropanoids via a vesicle transport system. Further experiment showed that inhibition of brassinosteroid biosynthesis by uniconazole suppressed TE differentiation, but not the secretion of UV-absorbing substances into the medium, implying that differentiation of xylem parenchyma cells might not be strongly affected by the depletion of endogenous brassinosteroids.
    Download PDF (1819K)
  • Toshihiko OKABE, Keita SUTOH, Takashi OKAMOTO, Takao MINAMIKAWA, Daisu ...
    Type: Original Paper
    2004 Volume 21 Issue 3 Pages 215-223
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    Pod storage protein (PSP) accumulates in both developing pods and wounded leaves of common bean (Phaseolus vulgaris). Since jasmonic acid (JA) is known to be involved in wound responses, we examined hormonal regulation of PSP expression. Methyl jasmonate (MeJA)-induced expression of PSP was blocked by both salicylic acid (SA) and ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). The PSP promoter fused to β-glucuronidase (GUS) coding region was introduced into Arabidoposis thaliana using Agrobacterium infection. No MeJA-inducible GUS expression was found in the transformants. The chimeric gene was then introduced into stems of common bean using particle bombardment. Exogenously applied MeJA enhanced GUS activity, and this was prevented by both SA and ACC. Deletion analysis of the promoter indicated that the region between positions-747 and-555 included cis-regulatory elements for JA induction and ethylene suppression, and that cis-elements for SA-suppression were located in the region downstream of position-86.
    Download PDF (1565K)
Short Communication
Note
  • Indra Dutt BHATT, Jung-In CHANG, Noboru HIRAOKA
    Type: Note
    2004 Volume 21 Issue 3 Pages 237-241
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    Brugmansia versicolor Lagerheim of the family Solanaceae was propagated through shoot tip culture and shoots were cold-stored in vitro at 5, 10 or 15°C under light or dark condition. All the shoots died after cold storage for 6 months at 5°C irrespective of light condition. When shoots were stored for 12 months at 15°C under light illumination, the best 100% survival rate was obtained. The plants regenerated from shoots stored for 6 or 12 months retained the ability to accumulate scopolamine as much as the control plants which were raised from shoots maintained under normal culture condition without cold-storage. These findings show that slow growth storage of in vitro B. versicolor shoots at 15°C can be used as a germplasm conservation system for short-or medium-term duration without deterioration of the ability to accumulate the secondary metabolites.
    Download PDF (642K)
  • Yoshihiro NAKANO, Satoshi OKAWA, Takayoshi YAMAUCHI, Yukio KOIZUMI, Ji ...
    Type: Note
    2004 Volume 21 Issue 3 Pages 243-246
    Published: 2004
    Released: April 28, 2005
    JOURNALS FREE ACCESS
    In radish (Raphanus sativus L.) cotyledons, γ-glutamyltransferase (GGT, EC 2.3.2.2) activity was detected in both fractions extracted with grinding buffer alone (low ionic strength buffer) and the same buffer supplemented with 1 M NaCl (high ionic strength buffer). The former was referred to as soluble GGT and the latter, as bound GGT. Bound GGT was not solubilized by 1% Triton X-100. The activities of both soluble and bound GGTs were inhibited by acivicin, an inhibitor of mammalian and Escherichia coli GGTs. The activity of GGT extracted with the high ionic strength buffer disappeared when protoplasts were prepared, indicating the localization of bound GGT to cell walls. These results strongly indicate the occurrence of two forms of GGTs, soluble and bound ones. The two forms of GGTs were also found in Arabidopsis thaliana, cabbage, pea, soybean, maize and rice among the eight plants tested, in addition to radish.
    Download PDF (564K)
feedback
Top