@article {4997, title = {Permanent stress adaptation and unexpected high light tolerance in the shade-adapted Chlamydomonas priscui}, journal = {Plants}, volume = {13}, year = {2024}, month = {08/2024}, pages = {2254}, abstract = {

The Antarctic photopsychrophile, Chlamydomonas priscui UWO241, is adapted to extreme environmental conditions, including permanent low temperatures, high salt, and shade. During long-term exposure to this extreme habitat, UWO241 appears to have lost several short-term mechanisms in favor of constitutive protection against environmental stress. This study investigated the physiological and growth responses of UWO241 to high-light conditions, evaluating the impacts of long-term acclimation to high light, low temperature, and high salinity on its ability to manage short-term photoinhibition. We found that UWO241 significantly increased its growth rate and photosynthetic activity at growth irradiances far exceeding native light conditions. Furthermore, UWO241 exhibited robust protection against short-term photoinhibition, particularly in photosystem I. Lastly, pre-acclimation to high light or low temperatures, but not high salinity, enhanced photoinhibition tolerance. These findings extend our understanding of stress tolerance in extremophilic algae. In the past 2 decades, climate change-related increasing glacial stream flow has perturbed long-term stable conditions, which has been associated with lake level rise, the thinning of ice covers, and the expansion of ice-free perimeters, leading to perturbations in light and salinity conditions. Our findings have implications for phytoplankton survival and the response to change scenarios in the light-limited environment of Antarctic ice-covered lakes.

}, keywords = {LTER-MCM, Cyclic electron flow, environmental change, extremophile, photo-acclimation, photoinhibition}, doi = {10.3390/plants13162254}, url = {https://www.mdpi.com/2223-7747/13/16/2254}, author = {Popson, Devon and D{\textquoteright}Silva, Susanna and Wheeless, Kaylie and Rachael M. Morgan-Kiss} }