Photoelectric responses in phototactic flagellated algae measured in cell suspensionстатья
Информация о цитировании статьи получена из
Scopus,
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация: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.