PHOTOMOVEMENT RESPONSES OF PORPHYRIDIUM PURPUREUM

Sylvia A. Hill, Leslie R. Towill, Milton R. Sommerfeld

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

The influence of light quality on positive phototopotaxis by the gliding, unicellular red alga Porphyridium purpureum was obtained using interference filters. Cells exposed to 3 × 10−7 mol · m2· s−1 of various wavelengths for 72 h showed maximum topotaxis at 420 and 440 nm. The lower threshold for positive, movement was approximately 5 × 10−8 mol · m−2· s−1. Random movement occurred at nonactinic wavelengths, and no movement occurred in the dark. Cell motility appeared to be unaffected by light polarity, suggesting that the photoreceptor(s) for topotaxis and photokinesis are randomly oriented.

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Keywords

  • action spectrum
  • gliding movement
  • phototaxis
  • Porphyridium
  • Rhodophyta

ASJC Scopus subject areas

  • Aquatic Science
  • Plant Science

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