Phobic Reactions between two Adjacent Monochromatic Light Fields

Abstract

Trichoms of the blue-green alga Phormidium uncinatum undergo a phobic reaction when they traverse by random movement from a field of photosystem II light (557 nm) to an adjacent field with light of a variable wavelength. According to the electron pool hypothesis, the wavelength dependency curve of organism accumulations resulting from repeated phobic reactions must be regarded as an action spectrum of photosystem I. This action spectrum is compared to one obtained with a double irradiation technique.