Inhibition of Photosynthesis in Certain Algae by Extreme Red Light.
This paper shows that in Porphyridium cruentum and in Chlorella pyrenoidosa (but apparently not in Anacystis nidulans) "extreme red" light (> 720 mmu) can inhibit photosynthesis produced by "far red" light (up to 720 mmu). From the action spectrum of this phenomenon, it appears that an unknown pigment with an absorption band around 745 mmu must be responsible for it.
Govindjee
E
E
Rabinowitch
J B
JB
Thomas