Research
| Title： | Exposure of cyanobacterium Nostoc sp. to the Mars-like stratosphere environment |
|---|---|
| First author： | Ye, Tong; Wang, Bo; Li, Caiyan; Bian, Po; Chen, Lanzhou; Wang, Gaohong |
| Journal： | JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY |
| Years： | 2021 |
| DOI： | 10.1016/j.jphotobiol.2021.112307 |
| Abstract： | During the HH-19-2 flight mission of the Chinese Scientific Experimental System, dried Nostoc sp. cells were exposed to the stratosphere environment (32,508 m altitude) for 3 h and 22 min. The atmospheric pressure, temperature, relative humidity, and ionizing and non-ionizing radiation levels at that altitude are similar to those on the surface of Mars. Although analyses revealed decreased photosynthetic activity, a decline in auto fluorescence, and damage to the cellular morphology in the flight-exposed sample, the death rate was low (28%). Physiological changes were not obvious after the exposure to the Mars-like vacuum conditions. The ground exposed samples showed a similar trend to the flight-exposed samples, but the damage was relatively slight. RNA-sequencing data revealed a number of affected metabolic pathways: photosynthetic system and CO2 fixation function, activation of antioxidant systems, heat shock protein, DNA repair, and protein synthesis. Results suggest that Nostoc sp. has the potential to survive in a Mars-like environment and that it may be a suitable pioneer species to colonize Mars in the future in closed life-support systems (base) or in localities with relatively suitable conditions for life, such as localities with water available. |
