|Leblond, Jeffrey - MIDDLE TN STATE UNIV|
Submitted to: International Conference on Harmful Algae Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 21, 2002
Publication Date: October 1, 2004
Citation: Evens, T.J., Leblond, J.D. 2004. Photophysiology of the Florida Red Tide Dinoflagellate, Karenia brevis: modifications in Thylakoid Lipid Composition in response to environmental conditions. In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo, G.A., editors. Harmful Algae 2002. St. Petersburg, Florida. USA:Florida Fish and Wildlike Conservation Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of UNESCO. p. 414-416. Technical Abstract: The marine dinoflagellate, Karenia brevis, has been recognized for decades as the source of large toxic blooms in the waters off of the west coast of Florida (USA), and is responsible for massive fish kills and myriad public health concerns. K. brevis thrives in the oligotrophic surface waters of the Gulf of Mexico, and is exposed there to highly variable levels of irradiance, UV radiation, temperature and nutrients. Many algae respond to stressful environmental conditions, such as extremes in temperature, by modulating the fatty acid composition of their thylakoid membranes, driven by the need to maintain the optimal fluidity/permeability necessary for efficient photosynthesis. Thylakoid membrane fluidity affects virtually all aspects of the light reactions of photosynthesis: the movement of the electron transport chain, the intra-and inter-orientations of the photo systems, and the maintenance of pH gradient (necessary for ATP production and the functioning of the xanthophyll cycle) are all heavily influenced. However, it is clearly not known how K. brevis modifies its thylakoid membrane composition in response to high fluxes of irradiance, temperature and/or nutrient stresses. The work presented herein will discuss the results of preliminary studies on how changes in environmental conditions affect the thylakoid membrane composition of K. brevis. The results will provide a better understanding of how this alga can survive and thrive in the surface waters of the Florida Gulf Coast.