<?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%">Hüner, Norman P. A.</style></author><author><style face="normal" font="default" size="100%">Smith, David R.</style></author><author><style face="normal" font="default" size="100%">Cvetkovska, Marina</style></author><author><style face="normal" font="default" size="100%">Zhang, Xi</style></author><author><style face="normal" font="default" size="100%">Alexander G. Ivanov</style></author><author><style face="normal" font="default" size="100%">Szyszka-Mroz, Beth</style></author><author><style face="normal" font="default" size="100%">Kalra, Isha</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%">Photosynthetic adaptation to polar life: Energy balance, photoprotection and genetic redundancy</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Plant Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">genomic redundancy</style></keyword><keyword><style  face="normal" font="default" size="100%">light</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">photopsychrophily</style></keyword><keyword><style  face="normal" font="default" size="100%">photopsychrotolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">temperature</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%">01/2022</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.sciencedirect.com/science/article/pii/S0176161721001966</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">268</style></volume><pages><style face="normal" font="default" size="100%">153557</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 persistent low temperature that characterize polar habitats combined with the requirement for light for all photoautotrophs creates a conundrum. The absorption of too much light at low temperature can cause an energy imbalance that decreases photosynthetic performance that has a negative impact on growth and can affect long-term survival. The goal of this review is to survey the mechanism(s) by which polar photoautotrophs maintain cellular energy balance, that is, photostasis to overcome the potential for cellular energy imbalance in their low temperature environments. Photopsychrophiles are photosynthetic organisms that are obligately adapted to low temperature (0-15 &amp;deg;C) but usually die at higher temperatures (&amp;ge;20 &amp;deg;C). In contrast, photopsychrotolerant species can usually tolerate and survive a broad range of temperatures (5-40 &amp;deg;C). First, we summarize the basic concepts of excess excitation energy, energy balance, photoprotection and photostasis and their importance to survival in polar habitats. Second, we compare the photoprotective mechanisms that underlie photostasis and survival in aquatic cyanobacteria and green algae as well as terrestrial Antarctic and Arctic plants. We show that polar photopsychrophilic and photopsychrotolerant organisms attain energy balance at low temperature either through a regulated reduction in the efficiency of light absorption or through enhanced capacity to consume photosynthetic electrons by the induction of O&lt;sub&gt;2&lt;/sub&gt;&amp;nbsp;as an alternative electron acceptor. Finally, we compare the published genomes of three photopsychrophilic and one photopsychrotolerant alga with five mesophilic green algae including the model green alga, &lt;em&gt;Chlamydomonas reinhardtii&lt;/em&gt;. We relate our genomic analyses to photoprotective mechanisms that contribute to the potential attainment of photostasis. Finally, we discuss how the observed genomic redundancy in photopsychrophilic genomes may confer energy balance, photoprotection and resilience to their harsh polar environment. Primary production in aquatic, Antarctic and Arctic environments is dependent on diverse algal and cyanobacterial communities. Although mosses and lichens dominate the Antarctic terrestrial landscape, only two extant angiosperms exist in the Antarctic. The identification of a single &amp;lsquo;molecular key&amp;rsquo; to unravel adaptation of photopsychrophily and photopsychrotolerance remains elusive. Since these photoautotrophs represent excellent biomarkers to assess the impact of global warming on polar ecosystems, increased study of these polar photoautotrophs remains essential.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>32</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kalra, Isha</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Rachael M. Morgan-Kiss</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Role of cyclic electron flow (CEF) and photosystem I (PSI) supercomplex formation during acclimation to long-term salinity stress in green algae: A comparative study</style></title><secondary-title><style face="normal" font="default" size="100%">Microbiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acclimation</style></keyword><keyword><style  face="normal" font="default" size="100%">CEF</style></keyword><keyword><style  face="normal" font="default" size="100%">extremophile</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">salinity stress</style></keyword><keyword><style  face="normal" font="default" size="100%">supercomplex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.proquest.com/docview/2572560585</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Miami University</style></publisher><pub-location><style face="normal" font="default" size="100%">Oxford, OH</style></pub-location><volume><style face="normal" font="default" size="100%">PhD</style></volume><pages><style face="normal" font="default" size="100%">236</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Photosynthesis is one of the most important processes on Earth by which organisms convert solar energy into usable forms of energy. Linear electron flow (LEF) and cyclic electron flow (CEF) constitute two major pathways in photosynthesis. While LEF leads to production of both ATP and NADPH, CEF only produces ATP that helps balance the ATP:NADPH ratio required for carbon fixation. CEF also plays a major role during acclimation to several environmental stressors. However, the regulation and mechanism by which CEF operates is still not clearly understood. Recent studies have shown that formation of a protein supercomplex with PSI appears to be essential for induction of CEF in several model organisms. However, both supercomplex formation and CEF induction have been mainly studied under short-term, transitory stress conditions. In addition, the role and mechanism by which organisms may rely on CEF to survive in their natural habitat and acclimate to stress over a long period of time has not been considered. In this study we compared how three photosynthetic organisms (one model alga, &lt;i&gt;Chlamydomonas reinhardtii&lt;/i&gt;; two extremophiles, &lt;i&gt;C.&lt;/i&gt; sp. UWO241 and &lt;i&gt;C.&lt;/i&gt; sp. ICE-MDV) utilize CEF to cope with their natural environment and adapt to steady-state environmental stress. To that end, the objectives of this thesis were i) to elucidate the role of CEF in long-term salinity acclimation ii) to understand the downstream changes associated with increased CEF, and iii) to identify whether PSI-supercomplexes are associated with increased CEF during salinity acclimation. We hypothesized that a stable PSI-supercomplex is required for high CEF, which in turn supports strong carbon fixation capacity for production of downstream metabolic products important for long-term acclimation to salinity stress. We showed for the first time, that increased CEF in UWO241 leads to excess ATP production and rewiring of downstream metabolism under high salinity. Next, we showed that a laboratory evolved salinity-tolerant strain of model &lt;i&gt;C. reinhardtii&lt;/i&gt; uses constitutive upregulation of CEF to deal with salinity stress, which is in-turn associated with increased non-photochemical quenching and rewired carbon metabolism. Last, we show that CEF is involved in salinity acclimation in all three &lt;i&gt;Chlamydomonas&lt;/i&gt; species, regardless of their salinity tolerance. We also show that PSI-supercomplexes are associated with increased CEF in these species. Characterization of high-salt supercomplex of &lt;i&gt;C. reinhardtii&lt;/i&gt; revealed that it shares many similarities with the extensively described state 2 supercomplex, and that supercomplex composition might be species dependent rather than stress dependent.</style></abstract><work-type><style face="normal" font="default" size="100%">Doctoral</style></work-type></record></records></xml>