Effect of light on sodium and chloride influxes in partly illuminatedNitella flexiliscells

摘要

Influx of sodium ion inNitella flexiliscell was stimulated two- to three-fold by light. This effect of light depended on the season as well as the conditions under which the plant was kept and disappeared on storage in the laboratory. Influx of chloride ion was also stimulated ten- to twenty-fold by light. The light effect on Cl influx was more stable, in comparison with that on Na influx. These light effects seem to be linked with photosynthesis based on the similarity between the action spectra of Na and Cl influxes and that of photosynthesis.In a partly illuminated cell, the accelerating effect of light on Na influx was not limited to the cellular part which was illuminated directly, but propagated to other parts of the cell which were not illuminated. On the other hand, the stimulating effect of light on Cl influx was limited to the directly illuminated cellular part.