title: Effects of Light and Salinity Stresses in Production of Mycosporine-Like Amino Acids by Gymnodinium catenatum (Dinophyceae).
abstract: Mycosporine-like amino acids (MAAs) were analyzed in a Portuguese Gymnodinium catenatum strain when transferred to high salinity and high light conditions. Total MAA concentrations increased progressively between 30 and 36 psu, attaining at 36 psu 2.9-fold the 30 psu treatment. When abruptly transferred to solar light in an outdoor shadowed location, MAA concentration increased steadily along the day for most compounds. After 8 h, mycosporine-glycine, palythene and M-319 attained or surpassed 25-fold their initial concentration, while M-370 only attained 4-fold concentration. When transferred from halogen to fluorescent light, polar MAAs such as shinorine and porphyra-334, increased until day two and then declined, while M-370 increase slowly, becoming the dominant compound from the profile after 1 week. These experiments put into evidence the relation of palythene with M-319, which was further identified as its acid degradation product, palythine. Acid degradation of M-370 originated M-324, while M-311 seems to be the precursor of M-370. Under high salinity and high light conditions chain formation was altered toward shorter chains or solitary cells. This alteration can represent a morphological stress sign, which in the natural environment could affect average population speed during daily vertical migrations.
authors.affiliation: Departamento do Mar e Recursos Marinhos, Instituto Português do Mar e da Atmosfera, I.P. (IPMA), Lisbon, Portugal.
authors.forename: Paulo
authors.identifier: http://orcid.org/0000-0002-2524-4453
authors.initials: P
authors.lastname: Vale
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis*; D004141:Dinoflagellida / Q000502:physiology* / Q000528:radiation effects*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D008027:Light; D054712:Salinity; D013312:Stress, Physiological
chemical_list: C569122:1050-Da MAA; D000596:Amino Acids