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Evidence Regarding the Possible Role of c ‐Phycoerythrin in Ultraviolet‐B Tolerance in a Thermophilic Cyanobacterium *
Author(s) -
Wingard Christopher E.,
Schiller Jonathan R.,
Castenholz Richard W.
Publication year - 1997
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1997.tb01931.x
Subject(s) - phycoerythrin , cyanobacteria , strain (injury) , biology , phycobiliprotein , photosynthesis , botany , chromatic adaptation , pigment , photosynthetic pigment , thermophile , wild type , chemistry , genetics , mutant , bacteria , gene , anatomy , flow cytometry , physics , organic chemistry , optics
— It was recently reported that a strain of Nostoc spongiaeforme (cyanobacteria) with the photopigment c ‐phycoerythrin ( c ‐PE) may be more tolerant of the adverse effects of UVB radiation than the same strain lacking c ‐PE due to chromatic adaptation (CA) (Tyagi et al., Photochem. Photobiol. 55,401–407, 1992). It was proposed that this increased UVB tolerance may be due to the presence of c ‐PE, perhaps as a function of the ability of strains with c ‐PE to chromatically adapt. We tested the role of c ‐PE in UVB tolerance by comparing the short‐and long‐term effects of UVB exposure on photosynthesis, pigmentation and the protein contents of four experimental cultures of the thermophilic cyanobacterium Os‐cillatoria cf. amphigranulata. These cultures consisted of a wild‐type strain that produces c ‐PE, a green pigment variant (subcloned from the parent wild‐type strain) incapable of producing c ‐PE and two chromatically adapted color forms of the wild‐type strain that varied with regard to their total c ‐PE content. There were no significant results suggesting a role for c ‐PE in UVB tolerance. It is concluded that the photopigment c ‐PE does not confer enhanced resistance to the deleterious effects of UVB radiation on photosynthesis in this cyanobacterium.