A complex photoreceptive structure in the cyanobacterium Leptolyngbya sp.
Among the terrestrial epilithic cyanobacteria isolated from Roman hypogea at extremely low light intensity, a non-heterocystous strain, belonging to the genus Leptolyngbya, showed a marked photobehavior. These red cyanobacteria possess an orange spot at the tip of the apical cell. Micro-spectrophotometric analysis of this tip showed an absorption spectrum with two bands, centered at 456 and 504 nm, respectively. Experiments on photo-orientation impairment of these cells, and micro-spectrophotometric analysis of the tip of impaired trichomes showed that a rhodopsin-like protein might be present in this structure. All these data could support the hypothesis of the presence of a complex photoreceptive system in this prokaryote.
Albertano
P
P
Dipartimento di Biologia, Università di Roma Tor Vergata, Italy.
Barsanti
L
L
Passarelli
V
V
Gualtieri
P
P
D001426:Bacterial Proteins / Q000032:analysis; D000458:Cyanobacteria / Q000502:physiology* / Q000648:ultrastructure*; D008027:Light; D015591:Microspectrophotometry; D020283:Photoreceptors, Microbial / Q000737:chemistry*
D001426:Bacterial Proteins; D020283:Photoreceptors, Microbial