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  -