02098nas a2200265   4500008004100000022001400041245010400055210006900159260001200228300001200240490000800252520131200260653001601572653001501588653001801603653002501621653002101646653001301667653002201680100001601702700001401718700001401732700002901746856005701775       2023                        eng d  a0166-859500aHigh salt-induced PSI-supercomplex is associated with high CEF and attenuation of state transitions0 aHigh saltinduced PSIsupercomplex is associated with high CEF and  c09/2023  a65 - 840 v1573 a<p>While PSI-driven cyclic electron flow (CEF) and assembly of thylakoid supercomplexes have been described in model organisms like <i>Chlamydomonas reinhardtii</i>, open questions remain regarding their contributions to survival under long-term stress. The Antarctic halophyte, <i>C. priscuii UWO241</i> (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, <i>C. reinhardtii</i>, and a moderately halotolerant Antarctic green alga, <i>C.</i> sp. ICE-MDV (ICE-MDV). CEF was activated under high salt and associated with increased non-photochemical quenching in all three <i>Chlamydomonas</i> 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.</p>10aacclimation10aAntarctica10aChlamydomonas10aCyclic electron flow10aPSI-supercomplex10asalinity10astate transitions1 aKalra, Isha1 aWang, Xin1 aZhang, Ru1 aMorgan-Kiss, Rachael, M.  uhttps://link.springer.com/10.1007/s11120-023-01032-y02435nas a2200277   4500008004100000245011000041210006900151260001200220300000700232490000700239520155100246653001501797653002601812653002401838653001301862653003001875100001901905700002401924700002101948700002401969700002101993700002302014700002202037700003302059856006502092       2022                        eng d00aLimits to the three domains of life: Lessons from community assembly along an Antarctic salinity gradient0 aLimits to the three domains of life Lessons from community assem  c04/2022  a150 v263 a<p>Extremophiles exist among all three domains of life; however, physiological mechanisms for surviving harsh environmental conditions differ among Bacteria, Archaea and Eukarya. Consequently, we expect that domain-specific variation of diversity and community assembly patterns exist along environmental gradients in extreme environments. We investigated inter-domain community compositional differences along a high-elevation salinity gradient in the McMurdo Dry Valleys, Antarctica. Conductivity for 24 soil samples collected along the gradient ranged widely from 50 to 8355 &micro;S cm<sup>-1</sup>. Taxonomic richness varied among domains, with a total of 359 bacterial, 2 archaeal, 56 fungal, and 69 non-fungal eukaryotic operational taxonomic units (OTUs). Richness for bacteria, archaea, fungi, and non-fungal eukaryotes declined with increasing conductivity (all <em>P</em>&thinsp;&lt;&thinsp;0.05). Principal coordinate ordination analysis (PCoA) revealed significant (ANOSIM <em>R</em>&thinsp;=&thinsp;0.97) groupings of low/high salinity bacterial OTUs, while OTUs from other domains were not significantly clustered. Bacterial beta diversity was unimodally distributed along the gradient and had a nested structure driven by species losses, whereas in fungi and non-fungal eukaryotes beta diversity declined monotonically without strong evidence of nestedness. Thus, while increased salinity acts as a stressor in all domains, the mechanisms driving community assembly along the gradient differ substantially between the domains.</p>10aAntarctica10ainter-domain response10aMcMurdo Dry Valleys10asalinity10aspecies richness patterns1 aJiang, Xiaoben1 aVan Horn, David, J.1 aOkie, Jordan, G.1 aBuelow, Heather, N.1 aSchwartz, Egbert1 aColman, Daniel, R.1 aFeeser, Kelli, L.1 aTakacs-Vesbach, Cristina, D.  uhttps://link.springer.com/article/10.1007/s00792-022-01262-302939nas a2200241   4500008004100000245010800041210006900149260001200218300001100230490000800241520220100249653000902450653001602459653003202475653001302507653001302520100001602533700001802549700001402567700001502581700002902596856007202625       2019                        eng d00aCommunity response of microbial primary producers to salinity is primarily driven by nutrients in lakes0 aCommunity response of microbial primary producers to salinity is  c12/2019  a1340010 v6963 a<p>Higher microbial diversity was frequently observed in saline than fresh waters, but the underlying mechanisms remains unknown, particularly in microbial primary producers (MPP). MPP abundance and activity are notably constrained by high salinity, but facilitated by high nutrients. It remains to be ascertained whether and how nutrients regulate the salinity constraints on MPP abundance and community structure. Here we investigated the impact of nutrients on salinity constraints on MPP abundance and diversity in undisturbed lakes with a wide salinity range on the Tibetan Plateau. MPP community was explored using quantitative PCR, terminal restriction fragment length polymorphism and sequencing of cloning libraries targeting form IC cbbL gene. The MPP community structure was sorted by salinity into freshwater (salinity&lt;1&permil;), saline (1&permil; &lt; salinity&lt;29&permil;) and hypersaline (salinity&gt;29&permil;) lakes. Furthermore, while MPP abundance, diversity and richness were significantly constrained with increasing salinity, these constraints were mitigated by enhancing total organic carbon (TOC) and total nitrogen (TN) contents in freshwater and saline lakes. In contrast, the MPP diversity increased significantly with the salinity in hypersaline lakes, due to the mitigation of enhancing TOC and TN contents and salt-tolerant MPP taxa. The mitigating effect of nutrients was more pronounced in saline than in freshwater and hypersaline lakes. The MPP compositions varied along salinity, with <em>Betaproteobacteria</em> dominating both the freshwater and saline lakes and <em>Gammaproteobacteria</em> dominating the hypersaline lakes. We concluded that high nutrients could mitigate the salinity constraining effects on MPP abundance, community richness and diversity. Our findings offer a novel insight into the salinity effects on primary producers and highlight the interactive effects of salinity and nutrients on MPP in lakes. These findings can be used as a baseline to illuminate the effects of increased anthropogenic activities altering nutrient dynamics on the global hydrological cycle and the subsequent responses thereof by MPP communities.</p>10acbbL10alake waters10amicrobial primary producers10anutrient10asalinity1 aYue, Linyan1 aKong, Weidong1 aJi, Mukan1 aLiu, Jinbo1 aMorgan-Kiss, Rachael, M.  uhttps://www.sciencedirect.com/science/article/pii/S0048969719339786