Effects of solar radiation on growth and mycosporine-like amino acids content in Thalassiosira sp, an Antarctic diatom

• Published in: Polar biology 2002, Vol.25 (1), p.12-20
• Main Authors: HERNANDO, M, CARRETO, J. I, CARIGNAN, M. O, FERREYRA, G. A, GROSS, C
• Format: Article
• Language: English
• Subjects: Amino acids; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Bacillariophyta; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Marine; Marine biology; mycosporine; Plankton; Plants and fungi; Solar radiation; Thalassiosira; Ultraviolet radiation
• ISSN: 0722-4060; 1432-2056
• DOI: 10.1007/s003000100306

The main objective of this study was to investigate the role of mycosporine-like amino acids (MAAs) in the short-term (hours) and long-term (several days) photoacclimation to solar ultraviolet radiation (UVR) of a marine Antarctic diatom (Thalassiosira sp.). The cultures were exposed to natural solar radiation and grown over 72 h and 6 days under three experimental irradiance treatments: (1) photosynthetic available radiation (PAR) + UVR (280-700 nm), (2) PAR + UVA (315-700 nm), and (3) PAR (400-700 nm). Two MAAs were identified and quantified in the cells: porphyra-334 and shinorine. The cultures showed an initial period of growth inhibition and the rate of synthesis of MAAs (µ) was very high in all treatments in the short-term experiment and during the first 2 days of the long-term experiment. No differences between treatments were observed in the accumulation of these compounds. After 2 days of exposure, however, the MAA content per cell was several times higher than that initially found in all treatments, and the cells exposed to the PAR + UVR treatment displayed the maximum concentration.[PUBLICATION ABSTRACT]