%0 Journal Article
%T Presence and absence of light-independent chlorophyll biosynthesis among Chlamydomonas green algae in an ice-covered Antarctic lake
%A David Roy Smith
%A Marina Cvetkovska
%A Norman P. A. H¨¹ner
%A Rachael Morgan-Kiss
%J Communicative & Integrative Biology
%D 2019
%R https://doi.org/10.1080/19420889.2019.1676611
%X ABSTRACT The cold, permanently ice-covered waters of Lake Bonney, Antarctica, may seem like an uninviting place for an alga, but they are home to a diversity of photosynthetic life, including Chlamydomonas sp. UWO241, a psychrophile residing in the deep photic zone. Recently, we found that UWO241 has lost the genes responsible for light-independent chlorophyll biosynthesis, which is surprising given that this green alga comes from a light-limited environment and experiences extended periods of darkness during the Antarctic winter. Why discard such a process? We argued that it might be linked to the very high dissolved oxygen concentration of Lake Bonney at the depth at which UWO241 is found. Oxygen is the Achilles¡¯ heel of the key enzyme involved in light-independent chlorophyll biosynthesis: DPOR. If this hypothesis is true, then other algae in Lake Bonney should also be susceptible to losing DPOR, such as Chlamydomonas sp. ICE-MDV, which predominantly resides in the chemocline, a depth with an even higher oxygen concentration than that where UWO241 exists. Here, we report that, contrary to our earlier prediction, ICE-MDV has maintained the genes encoding DPOR. We briefly discuss the implications of this finding in relation to the loss of light-independent chlorophyll synthesis in UWO241
%U https://www.tandfonline.com/doi/full/10.1080/19420889.2019.1676611