TY - JOUR A1 - Huwe, Björn A1 - Fiedler, Annelie A1 - Moritz, Sophie A1 - Rabbow, Elke A1 - de Vera, Jean-Pierre Paul A1 - Joshi, Jasmin Radha T1 - Mosses in Low Earth Orbit BT - Implications for the Limits of Life and the Habitability of Mars JF - Astrobiology N2 - As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of abiotic space- and Mars-like conditions were performed to analyze the resistance of a range of model organisms. The simulated abiotic space- and Mars-stressors were extreme temperatures, vacuum, and Mars-like surface ultraviolet (UV) irradiation in different atmospheres. We present for the first time simulated space exposure data of mosses using plantlets of the bryophyte genus Grimmia, which is adapted to high altitudinal extreme abiotic conditions at the Swiss Alps. Our preflight tests showed that severe UVR200-400nm irradiation with the maximal dose of 5 and 6.8 x 10(5) kJ center dot m(-2), respectively, was the only stressor with a negative impact on the vitality with a 37% (terrestrial atmosphere) or 36% reduction (space- and Mars-like atmospheres) in photosynthetic activity. With every exposure to UVR200-400nm 10(5) kJ center dot m(-2), the vitality of the bryophytes dropped by 6%. No effect was found, however, by any other stressor. As the mosses were still vital after doses of ultraviolet radiation (UVR) expected during the EXPOSE-R2 mission on ISS, we show that this earliest extant lineage of land plants is highly resistant to extreme abiotic conditions. KW - Extremotolerant KW - Bryophyte KW - Plant performance KW - Grimmia sp KW - Irradiation KW - UV irradiation Y1 - 2019 U6 - https://doi.org/10.1089/ast.2018.1889 SN - 1531-1074 SN - 1557-8070 VL - 19 IS - 2 SP - 221 EP - 232 PB - Liebert CY - New Rochelle ER - TY - JOUR A1 - Schwarzer, Christian A1 - Joshi, Jasmin Radha T1 - Parallel adaptive responses to abiotic but not biotic conditions after cryptic speciation in European peat moss Sphagnum magellanicum Brid JF - Perspectives in plant ecology, evolution and systematics N2 - Sphagnum magellanicum Brid. is a worldwide distributed peat moss and an ecosystem-engineer in temperate and boreal bog ecosystems suggesting a great adaptive potential to different environmental conditions. Phenotypes of S. magellanicum have been described as one species so far, although this has been questioned by the detection of several genetic groups in a recent global study. Concordant with morphological uniformity, our analyses of Mid-to Northern European plants revealed only minimal variation in nuclear nrITS and plastid rps4 sequences. However, we detected two distinct genetic groups within Europe by analyzing microsatellite data of 298 individuals from 27 populations. Plants formed an Eastern and a Western European cluster, with overlapping areas in northern Germany and southern Sweden where plants of both clusters coexist within populations but show no signs of admixture. These two cryptic taxa seem therefore to be reproductively isolated. Bayesian analyses indicated that reproductive isolation occurred before the end of the late Pleistocene glaciations. After the meltdown of the glaciers, both clusters colonized northern and central Europe from glacial refugia in the West and possibly from Euro-Siberian populations. To test for divergent adaptation to environmental conditions, we exposed plants of both clusters to experimental climate warming treatments at two different plant-diversity levels (monocultures vs. mixtures) for two years. Despite their different evolutionary history, plants of both genetic clusters responded equally to climate treatments in our southern common garden near Potsdam, Germany. However, only eastern cluster populations benefited from plant-community diversity and increased their biomass in mixtures. These differences in their ecological niche match the diverging microhabitat preferences observed in situ and may effectively hamper genetic exchange if distances between microhabitats are too large for Sphagnum sperm movement. (C) 2017 Elsevier GmbH. All rights reserved. KW - Bryophyte KW - Global change KW - Adaptation KW - Allopatric/sympatric speciation KW - Biodiversity KW - Post glacial colonization Y1 - 2017 U6 - https://doi.org/10.1016/j.ppees.2017.03.001 SN - 1433-8319 VL - 26 SP - 14 EP - 27 PB - Elsevier CY - Jena ER -