Effects of Ultraviolet Radiation (UVA+UVB) on Young Gametophytes of Gelidium floridanum: Growth Rate, Photosynthetic Pigments, Carotenoids, Photosynthetic Performance, and Ultrastructure
Carmen Simioni, Éder C. Schmidt, Marthiellen R. de L. Felix, Luz Karime Polo, Ticiane Rover, Marianne Kreusch, Debora T. Pereira, Fungyi Chow, Fernanda Ramlov, Marcelo Maraschin and Zenilda L. Bouzon
Article first published online: 23 JUN 2014 | DOI: 10.1111/php.12296
The radiation (PAR+UVA+UVB) on the young gametophytes of Gelidium floridanum affected the structure and resulted in depigmentation of the thallus and growth rate reduction. PAR+UVA+UVB promoted increase in cell wall thickness, increased of carotenoids compounds, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin, suffered significant reduction in concentration after exposure to PAR+UVA+UVB. This result agrees with the decrease in photosynthetic performance observed after exposing to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR).