Some Observations Related to Red — Far Red Antagonism in Germination of Spores of the Cyanobacterium Anabaena fertilissima

Abstract

Effects of intermittent short duration exposures of red (650 nm) and/or far red (725-750 nm) illuminations on spore germination were studied in Anabaena fertilissima . Spore germination was induced by red light while far red irradiation inhibited it. In reversal experiments, induction of germination by red light was annulled when the spores were subsequently exposed to far red light whereas inhibition due to far red illumination was overcome when spores were subjected to consequent red light treatment. Such antagonistic effects of red - far red irradiations provide evidence for the operation of photoinduction-photoreversal phenomenon mediated by a pigment which seems to be functionally similar to phytochrome of higher plants.