Mechanism of Bioactive Substances Involved in Tropisms of Higher Plants

DOI

Bibliographic Information

Other Title
  • 植物の屈性現象に関わる生理活性物質の機能解明

Description

<p>The phenomenon involving the curvature of plant seedlings toward light is called "phototropism", while the bending of the organs of a plant toward or away from the earth is called “gravitropism”. We have hitherto reported evidence that the differential flank growth that causes phototoropic curvature is regulated by a local gradient induced at the site of illumination, of blue light-induced growth inhibitors interfering with the action of evenly distributed auxin (Bruinsma-Hasegawa theory). We have already found that different plant species turn out to produce different and very specific growth inhibitors as candidates for phototropism-regulating and gravitropism-regulating substances. In this study, we report mechanisms of the growth inhibitors involved in the phototropism and gravitropism of higher plants.</p><p> We have already isolated two growth inhibitory substances involved in phototropism, MTBI and Raphanusanin from radish (Raphanus sativus) hypocotyls. To elucidate the mechanism of growth inhibition by MTBI and Raphanusanin, chemical and physiological methods have been performed. At first, we synthesized MTBG, a precursor of MTBI, and MTBI and Raphanusanin. The results of biological activities of these compounds revealed that MTBI and Raphanusanin were contributed to their growth inhibitory activity by promoting H2O2 production and subsequent lignification, which could increase the stiffness at the primary cell-wall level. </p><p>On the other hand, we found that two growth inhibitors, DIMBOA and MBOA, of which content in maize (Zea mays L.) coleoptiles were increased by the gravitropic stimulation. The results of biological activities of DIMBOA and MBOA indicated that they were contributed to their growth inhibitory activity by promoting H2O2 production and subsequent lignification, which could increase the stiffness as well as the manner of radish hypocotyls. These results suggest that gravitropic stimulation suppresses the growth rate of upper side of maize coleoptiles by increasing the content of DIMBOA and MBOA, causing a gravitropic response.</p>

Journal

Details 詳細情報について

  • CRID
    1390845713004335360
  • NII Article ID
    130007494654
  • DOI
    10.24496/tennenyuki.57.0_posterp49
  • ISSN
    24331856
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

Report a problem

Back to top