The occurrence of mycosporine-like amino acids in the gametophytic and sporophytic stages of Bangia (Bangiales, Rhodophyta)

Abstract

C. Boedeker and U. Karsten. 2005. The occurrence of mycosporine-like amino acids in the gametophytic and sporophytic stages of Bangia (Bangiales, Rhodophyta). Phycologia 44: 403–408.Ultraviolet-absorbing mycosporine-like amino acids (MAAs) were identified and quantified in both the gametophytic and sporophytic life stages of the cosmopolitan intertidal genus Bangia. Field samples were compared with culture material originating from different biogeographic regions, including freshwater populations. All cultures were kept for a long time under low-irradiance conditions prior to MAA analysis. Within all isolates investigated, four distinct compounds were found which were identified as shinorine, porphyra-334, asterina-330 and palythine. Gametophytic filaments always exhibited high concentrations of MAAs, with porphyra-334 being the dominant compound. Field and culture material did not differ in the amount of MAAs, indicating that Bangia does not adjust the amount of sunscreens to environmental conditions. Freshwater isolates contained lower amounts of MAAs compared to marine strains. However, a biogeographical trend in MAA contents reflecting the origin of the samples from habitats with different climate and insolation was not observed. Even the shell-boring sporophytic conchocelis stage contained significant amounts of MAAs, but in lower concentrations than the gametophytes, raising the possibility of MAAs fulfiling different functions in the two life stages.