<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Popson, Devon</style></author><author><style face="normal" font="default" size="100%">D’Silva, Susanna</style></author><author><style face="normal" font="default" size="100%">Wheeless, Kaylie</style></author><author><style face="normal" font="default" size="100%">Rachael M. Morgan-Kiss</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Permanent stress adaptation and unexpected high light tolerance in the shade-adapted &lt;i&gt;Chlamydomonas priscui&lt;/i&gt;</style></title><secondary-title><style face="normal" font="default" size="100%">Plants</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cyclic electron flow</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental change</style></keyword><keyword><style  face="normal" font="default" size="100%">extremophile</style></keyword><keyword><style  face="normal" font="default" size="100%">photo-acclimation</style></keyword><keyword><style  face="normal" font="default" size="100%">photoinhibition</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2024</style></year><pub-dates><date><style  face="normal" font="default" size="100%">08/2024</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.mdpi.com/2223-7747/13/16/2254</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">13</style></volume><pages><style face="normal" font="default" size="100%">2254</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The Antarctic photopsychrophile, &lt;i&gt;Chlamydomonas priscui&lt;/i&gt; 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.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">16</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kalra, Isha</style></author><author><style face="normal" font="default" size="100%">Wang, Xin</style></author><author><style face="normal" font="default" size="100%">Zhang, Ru</style></author><author><style face="normal" font="default" size="100%">Rachael M. Morgan-Kiss</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">High salt-induced PSI-supercomplex is associated with high CEF and attenuation of state transitions</style></title><secondary-title><style face="normal" font="default" size="100%">Photosynthesis Research</style></secondary-title><short-title><style face="normal" font="default" size="100%">Photosynth Res</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acclimation</style></keyword><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">Chlamydomonas</style></keyword><keyword><style  face="normal" font="default" size="100%">Cyclic electron flow</style></keyword><keyword><style  face="normal" font="default" size="100%">PSI-supercomplex</style></keyword><keyword><style  face="normal" font="default" size="100%">salinity</style></keyword><keyword><style  face="normal" font="default" size="100%">state transitions</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2023</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2023</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://link.springer.com/10.1007/s11120-023-01032-y</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">157</style></volume><pages><style face="normal" font="default" size="100%">65 - 84</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;While PSI-driven cyclic electron flow (CEF) and assembly of thylakoid supercomplexes have been described in model organisms like &lt;i&gt;Chlamydomonas reinhardtii&lt;/i&gt;, open questions remain regarding their contributions to survival under long-term stress. The Antarctic halophyte, &lt;i&gt;C. priscuii UWO241&lt;/i&gt; (UWO241), possesses constitutive high CEF rates and a stable PSI-supercomplex as a consequence of adaptation to permanent low temperatures and high salinity. To understand whether CEF represents a broader acclimation strategy to short- and long-term stress, we compared high salt acclimation between the halotolerant UWO241, the salt-sensitive model, &lt;i&gt;C. reinhardtii&lt;/i&gt;, and a moderately halotolerant Antarctic green alga, &lt;i&gt;C.&lt;/i&gt; sp. ICE-MDV (ICE-MDV). CEF was activated under high salt and associated with increased non-photochemical quenching in all three &lt;i&gt;Chlamydomonas&lt;/i&gt; species. Furthermore, high salt-acclimated cells of either strain formed a PSI-supercomplex, while state transition capacity was attenuated. How the CEF-associated PSI-supercomplex interferes with state transition response is not yet known. We present a model for interaction between PSI-supercomplex formation, state transitions, and the important role of CEF for survival during long-term exposure to high salt.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stahl-Rommel, Sarah</style></author><author><style face="normal" font="default" size="100%">Kalra, Isha</style></author><author><style face="normal" font="default" size="100%">D'Silva, Susanna</style></author><author><style face="normal" font="default" size="100%">Hahn, Mark M.</style></author><author><style face="normal" font="default" size="100%">Popson, Devon</style></author><author><style face="normal" font="default" size="100%">Cvetkovska, Marina</style></author><author><style face="normal" font="default" size="100%">Rachael M. Morgan-Kiss</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, &lt;i&gt;Chlamydomonas&lt;/i&gt; sp. UWO 241 (renamed &lt;i&gt;Chlamydomonas priscuii&lt;/i&gt;)</style></title><secondary-title><style face="normal" font="default" size="100%">Photosynthesis Research</style></secondary-title><short-title><style face="normal" font="default" size="100%">Photosynth Res</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">ascorbate</style></keyword><keyword><style  face="normal" font="default" size="100%">Cyclic electron flow</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosystem I</style></keyword><keyword><style  face="normal" font="default" size="100%">Psychrophile</style></keyword><keyword><style  face="normal" font="default" size="100%">ROS</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2022</style></year><pub-dates><date><style  face="normal" font="default" size="100%">03/2022</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://link.springer.com/article/10.1007/s11120-021-00877-5</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">151</style></volume><pages><style face="normal" font="default" size="100%">235 - 250</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Under environmental stress, plants and algae employ a variety of strategies to protect the photosynthetic apparatus and maintain photostasis. To date, most studies on stress acclimation have focused on model organisms which possess limited to no tolerance to stressful extremes. We studied the ability of the Antarctic alga &lt;i&gt;Chlamydomonas&lt;/i&gt; sp. UWO 241 (UWO 241) to acclimate to low temperature, high salinity or high light. UWO 241 maintained robust growth and photosynthetic activity at levels of temperature (2 &amp;deg;C) and salinity (700 mM NaCl) which were nonpermissive for a mesophilic sister species, &lt;i&gt;Chlamydomonas raudensis&lt;/i&gt; SAG 49.72 (SAG 49.72). Acclimation in the mesophile involved classic mechanisms, including downregulation of light harvesting and shifts in excitation energy between photosystem I and II. In contrast, UWO 241 exhibited high rates of PSI-driven cyclic electron flow (CEF) and a larger capacity for nonphotochemical quenching (NPQ). Furthermore, UWO 241 exhibited constitutively high activity of two key ascorbate cycle enzymes, ascorbate peroxidase and glutathione reductase and maintained a large ascorbate pool. These results matched the ability of the psychrophile to maintain low ROS under short-term photoinhibition conditions. We conclude that tight control over photostasis and ROS levels are essential for photosynthetic life to flourish in a native habitat of permanent photooxidative stress. We propose to rename this organism &lt;i&gt;Chlamydomonas priscuii&lt;/i&gt;.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cook, Greg</style></author><author><style face="normal" font="default" size="100%">Teufel, Amber</style></author><author><style face="normal" font="default" size="100%">Kalra, Isha</style></author><author><style face="normal" font="default" size="100%">Li, Wei</style></author><author><style face="normal" font="default" size="100%">Wang, Xin</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Rachael M. Morgan-Kiss</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The Antarctic psychrophiles &lt;i&gt;Chlamydomonas&lt;/i&gt; spp. UWO241 and ICE-MDV exhibit differential restructuring of photosystem I in response to iron</style></title><secondary-title><style face="normal" font="default" size="100%">Photosynthesis Research</style></secondary-title><short-title><style face="normal" font="default" size="100%">Photosynth Res</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">Cyclic electron flow</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosystem I</style></keyword><keyword><style  face="normal" font="default" size="100%">Psychrophile</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2019</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2019</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://link.springer.com/article/10.1007/s11120-019-00621-0</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">9</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;em&gt;Chlamydomonas &lt;/em&gt;sp. UWO241 is a psychrophilic alga isolated from the deep photic zone of a perennially ice-covered Antarctic lake (east lobe Lake Bonney, ELB). Past studies have shown that &lt;em&gt;C&lt;/em&gt;. sp. UWO241 exhibits constitutive downregulation of photosystem I (PSI) and high rates of PSI-associated cyclic electron flow (CEF). Iron levels in ELB are in the nanomolar range leading us to hypothesize that the unusual PSI phenotype of &lt;em&gt;C&lt;/em&gt;. sp. UWO241 could be a response to chronic Fe-deficiency. We studied the impact of Fe availability in &lt;em&gt;C&lt;/em&gt;. sp. UWO241, a mesophile, C. &lt;em&gt;reinhardtii&lt;/em&gt; SAG11-32c, as well as a psychrophile isolated from the shallow photic zone of ELB, &lt;em&gt;Chlamydomonas&lt;/em&gt; sp. ICE-MDV. Under Fe-deficiency, PsaA abundance and levels of photooxidizable P700 (ΔA&lt;sub&gt;820&lt;/sub&gt;/A&lt;sub&gt;820&lt;/sub&gt;) were reduced in both psychrophiles relative to the mesophile. Upon increasing Fe, &lt;em&gt;C&lt;/em&gt;. sp. ICE-MDV and C. &lt;em&gt;reinhardtii&lt;/em&gt; exhibited restoration of PSI function, while &lt;em&gt;C&lt;/em&gt;. sp. UWO241 exhibited only moderate changes in PSI activity and lacked almost all LHCI proteins. Relative to Fe-excess conditions (200 μM Fe&lt;sup&gt;2+&lt;/sup&gt;), &lt;em&gt;C&lt;/em&gt;. sp. UWO241 grown in 18 μM Fe&lt;sup&gt;2+&lt;/sup&gt; exhibited downregulation of light harvesting and photosystem core proteins, as well as upregulation of a bestrophin-like anion channel protein and two CEF-associated proteins (NdsS, PGL1). Key enzymes of starch synthesis and shikimate biosynthesis were also upregulated. We conclude that in response to variable Fe availability, the psychrophile &lt;em&gt;C&lt;/em&gt;. sp. UWO241 exhibits physiological plasticity which includes restructuring of the photo-chemical apparatus, increased PSI-associated CEF, and shifts in downstream carbon metabolism toward storage carbon and secondary stress metabolites.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue></record></records></xml>