Editorial: Revisiting the limits of plant life - plant adaptations to extreme terrestrial environments relating to astrobiology and space biology.

This research is all about how we can grow plants on other planets or in space to help us live there. Scientists are trying to understand which types of seeds will do best when they're not around Earth's atmosphere and sunlight, but instead have different conditions like less light from the Sun and a thinner air that doesn't hold heat well. They found out some cool things about how tiny plants (seedlings) start growing in these tough places-it seems their seeds need to be more spread out so they can poke through the ground easier, especially when it gets really cold or dry outside. Also, there are scientists looking for signs of life on other planets that might have different stars than our Sun. They're trying to figure out if tiny green bacteria called cyanobacteria could survive and grow by using the light from these cooler stars-lights we can’t even see with our eyes! This is important because finding life on other planets would be a huge deal for us here.

This Research Topic brings together a collection of studies aimed at understanding plant survival in extreme or extraterrestrial environments. The methodologies employed across these investigations vary but share an underlying goal to enhance our knowledge about how plants can adapt and thrive beyond Earth's protective influence, which is crucial for future space exploration endeavors where humanity seeks to deploy plant life as part of mission-critical functions in deep space. Key findings from the research include insights into seedling emergence under low bulk densities that promote germination and growth-a discovery with potential implications for establishing vegetation on other planets or moons where soil conditions may differ significantly from Earth's. Additionally, studies exploring photosynthesis in cyanobacteria have revealed the possibility of oxygenic photosynthesis under light spectra emitted by faint and cool stars (M-dwarfs), which is different from our Sun that predominantly emits visible and UV spectrum.