Journal of Plant Research

, Volume 110, Issue 3, pp 363–370

Phytochrome-mediated branch formation in protonemata of the mossCeratodon purpureus

  • Takatoshi Kagawa
  • Tilman Lamparter
  • Elmar Hartman
  • Masamitsu Wada
Original Articles

DOI: 10.1007/BF02524935

Cite this article as:
Kagawa, T., Lamparter, T., Hartman, E. et al. J. Plant Res. (1997) 110: 363. doi:10.1007/BF02524935

Abstract

We have analyzed light induction of side-branch formation and chloroplast re-arrangement in protonemata of the mossCeratodon purpureus. After 12 hr of dark adaptation, the rate of branch formation was as low as 5%. A red light treatment induced formation of side branches up to 75% of the dark-adapted protonema. The frequency of light induced branch formation differed between cells of different ages, the highest frequency being found in the 5th cell, the most distal cell studied from the apex. We examined the effect of polarized light given parallel to the direction of filament growth. The position of branching within the cell depended on the vibration plane of polarized red light. Branch formation was highest when the electric vector of polarized light vibrates parallel to the cell surface and is fluence rate dependent. The positional effect of polarized red light could be nullified to some extent by simultaneous irradiation with polarized far-red light. An aphototropic mutant,ptr116, shows characteristics of deficiency in biosynthesis of the phytochrome chromophore and exhibits no red-light induced branch formation. Biliverdin, a precursor of the phytochrome chromophore, rescued the red-light induced branching when added to the medium, supporting the conclusion that phytochrome acts as photoreceptor for red light induced branch formation. The light effect on chloroplast re-arrangement was also analyzed in this study. We found that polarized blue light induced chloroplast re-arrangement in wild-type cells, whereas polarized red light was inactive. This result suggests that chloroplast re-arrangement is only controlled by a blue light photoreceptor, not by phytochrome inCeratodon.

Key words

Blue light photoreceptor Branching Ceratodon purpureus Chloroplast movement Phytochrome (action dichroism) 

Abbreviations

B

blue light

F

flanking position

FR

far-red light

H

pol. light, horizontally-vibrating polarized light

I

intermediate position

IR

infra-red

R

red light

T

top-or-bottom position

V

pol. light, vertically-vibrating polarized light

wt

wild type

Copyright information

© The Botanical Society of Japan 1997

Authors and Affiliations

  • Takatoshi Kagawa
    • 1
  • Tilman Lamparter
    • 2
  • Elmar Hartman
    • 2
  • Masamitsu Wada
    • 3
  1. 1.Laboratory for Photoperception and Signal TransductionFRP, RIKEN InstituteSaitamaJapan
  2. 2.Institute for Plant Physiology and MicrobiologyBerlin Free UniversityBerlinGermany
  3. 3.Department of Biology, Faculty of ScienceTokyo Metropolitan UniversityTokyoJapan

Personalised recommendations