Photoelectric responses in phototactic flagellated algae measured in cell suspension

O. A. Sineshchekov, E. G. Govorunova, A. Dér, L. Keszthelyi, W. Nultsch

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

A new method for the investigation of electric responses involved in the light reception in microorganisms has been developed. It is based on the detection of photoelectric signals in suspensions of cells (instead of a single cell) by two different techniques: (a) by unilateral excitation of non-oriented cells and (b) after preorientation of the cells (e.g. by gravitaxis or weak, phototactically active light). The method was applied to the flagellated green algae Haematococcus and Chlamydomonas (and several of its mutants). Three main components of the electric signal, which differs in their origin and the mechanisms underlying that registration, were identified. Fast (microsecond) responses reflect charge separation in reaction centres of photosynthesis and are due to the classical light gradient effect on unilateral flash excitation. The later components of the electric signal are involved in photoreception and represent the photoreceptor potential of phototaxis and the calcium-dependent regenerative response. They are measured because of the directional sensitivity of the photoreceptor antenna and the asymmetry of localization of the electric currents involved in the sensory transduction chain. A general similarity between the electric responses in both organisms shows that the sensory transduction chain of photomovements in Chlamydomonas is similar to that described previously for Haematococcus. The advantages of the proposed method are discussed.

Original languageEnglish
Pages (from-to)119-134
Number of pages16
JournalJournal of Photochemistry and Photobiology, B: Biology
Volume13
Issue number2
DOIs
Publication statusPublished - Apr 30 1992

Fingerprint

algae
Algae
cell suspension culture
Suspensions
Haematococcus
Chlamydomonas
photoreceptors
cells
Light
Photosynthesis
Electric currents
geotaxis
Microorganisms
phototaxis
electric current
Chlorophyta
photosynthesis
Calcium
microorganisms
polarization (charge separation)

Keywords

  • charge separation
  • Chlamydomonas
  • flagellated algae
  • Haematococcus
  • ion current
  • light gradient
  • mutants
  • Photoelectric response
  • photophobic response
  • phototaxis
  • receptor potential
  • regenerative response
  • sensory transduction

ASJC Scopus subject areas

  • Plant Science
  • Bioengineering
  • Physical and Theoretical Chemistry

Cite this

Photoelectric responses in phototactic flagellated algae measured in cell suspension. / Sineshchekov, O. A.; Govorunova, E. G.; Dér, A.; Keszthelyi, L.; Nultsch, W.

In: Journal of Photochemistry and Photobiology, B: Biology, Vol. 13, No. 2, 30.04.1992, p. 119-134.

Research output: Contribution to journalArticle

Sineshchekov, O. A. ; Govorunova, E. G. ; Dér, A. ; Keszthelyi, L. ; Nultsch, W. / Photoelectric responses in phototactic flagellated algae measured in cell suspension. In: Journal of Photochemistry and Photobiology, B: Biology. 1992 ; Vol. 13, No. 2. pp. 119-134.
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