Scientists have revealed that moss spores have survived long journeys into space. The spores spent nine months outside the International Space Station (ISS) before returning to our planet, and more than 80% of the spores were still able to reproduce when they returned to Earth.
The discovery improves our understanding of how plant species survive in extreme conditions, the researchers wrote in their findings published Thursday (Nov. 20) in the journal Nature. iscience,
Previous experiments have shown how plants can cope in space, but until now, they have focused on larger organisms Like bacteria or plant crops. Now, researchers have shown samples of moss Physcomitrium patents ,P, patent) can not only survive but also thrive in space.
First, the researchers tested three types of cells. P. patens From different stages of the reproductive cycle of moss. They found that sporophytes – the cell structures that surround the spores – showed the greatest stress tolerance when exposed to ultraviolet (UV) light, cold and heat.
The sporophyte samples were then placed outside the ISS in a special exposure feature Attached to Japan’s Kibo module, where the samples remained for about nine months in 2022. After this time, the samples were returned to Earth.
“Surprisingly, more than 80% of the spores survived and many germinated normally,” said the study’s lead author. Tomomichi Fujitaa professor of plant biology at Hokkaido University in Japan told Live Science in an email. From this study, Fujita and his team developed a model that suggests that algae spores could actually survive in space for up to 5,600 days, or about 15 years.
Back on Earth, the team found that most conditions – including the vacuum of space, microgravity and extreme temperature fluctuations – had limited effect on the algal spores. However, samples that were exposed to light, particularly high-energy wavelengths of UV light, fared less well. Levels of pigment used by moss photosynthesisSuch as chlorophyll a, were significantly reduced as a result of light damage, which subsequently affected the growth of algae.
Even though some samples of moss suffered damage from the conditions of outer space, P. patens Still fared much better than other plant species that had previously been tested under similar conditions. Fujita believes that the protective, spongy covering around the spores may help protect against UV light and dehydration.
“This protective role may have evolved early in the history of terrestrial plants to help mosses colonize terrestrial habitats,” he said.
While it may seem like an exercise in testing the limits of a single species, “the success of spores in space could offer a biological stepping stone to building ecosystems beyond our planet,” Fujita said. In the future, they hope to test other species and better understand how these resilient cells survive under such stressful conditions.
<a href