02006nas a2200133 4500008004100000245016300041210006900204260003900273490000900312520143800321100001501759700002901774856006901803 2018 eng d00aAntarctic Chlamydomonas strains C. sp. UWO241 and ICE-MDV exhibit differential restructuring of the photosynthetic apparatus in response to iron0 aAntarctic iChlamydomonasi strains iCi sp UWO241 and ICEMDV exhib aOxford, OHbMiami Universityc20180 vM.S.3 a

As an integral cofactor for many redox-associated processes, iron (Fe) homeostasis is crucial in order to produce sufficient energy for the organism. Fe limitation, or excess, can cause major alterations in the function and structure of the photosynthetic apparatus. Photosynthetic psychrophiles grown under permanent low temperatures exhibit novel adaptations in their photosynthetic apparatus to deal with this permanent stress. The ice-covered lakes of the McMurdo Dry Valleys harbor many species of cold-adapted algae, including Chlamydomonas sp. UWO241 (UWO241). As a consequence of adaptation to multiple permanent extreme conditions, UWO241 exhibits a remodeled photosynthetic apparatus for maintaining redox poise. One unusual characteristic of UWO241 is the absence of a PSI-associated 77K fluorescence emission under a wide range of growth conditions. This phenotype resembles Fe deficiency in other model organisms such as C. reinhardtii. We hypothesized that adaptation to permanent iron deficiency in its native environment may contribute to this unusual phenotype. We compared the effect of Fe availability on the physiology and photobiology of UWO241 with the model C. reinhardtii as well as a second psychrophilic alga, Chlamydomonas sp. ICE-MDV (ICE). The impacts of a restructured photosynthetic apparatus on the unique Fe-associated phenotype in UWO241 will be discussed.

1 aCook, Greg1 aMorgan-Kiss, Rachael, M. uhttp://rave.ohiolink.edu/etdc/view?acc_num=miami1525455621778836