Whilst flicking through the news pages of National Geographic’s website, I found this really interesting article about growing plants without gravity.
In 2010 researchers sent Arabidopsis thaliana seeds to the international space station to study how the roots of plants develop in a weightless environment.
Growing plants on the International Space Station. Image taken from http://news.nationalgeographic.com.au/news/2012/121207-plants-grow-space-station-science/ courtesy of NASA.
Based on current knowledge and research it’s thought that gravity has an important effect on root growth, however in this experiment scientists found that gravity wasn’t necessary for the Arabidopsis thaliana plants to flourish. The researchers of this study think that the reason for this may be due to the ability of plants to orientate themselves as they are growing. In the weightless environment, the seeds behaved as they normally would on Earth with gravity; they sprouted roots that grew away from the seed in search of water and nutrients.
For this study, the plants were grown on a nutrient rich gel and as the roots grew, they grew with a ‘skewing’ pattern, which is where the roots slant progressively as they branch out. ‘Skewing’ was originally considered to be the result of gravity influencing how the root tip interacted with the surface it encountered as it was growing. The phenomenon of skewing in a gravity free environment suggests that plants use other cues, like water, nutrients and light to direct roots.
According to plant geneticist Anna-Lisa Paul, the role of gravity on plant growth and development was considered to be “well understood”, however this research showed that the “…features of plant growth we thought were a result of gravity acting on plant cells and organs do not actually require gravity.”
Research like this takes us one step closer to being able to cultivate plants in space, whether or not this is a good thing is yet to be seen.
The full article Plants Grow Fine without Gravity can be viewed on the National Geographic news page and the abstract of the research paper Plant Growth Strategies are Re-modelled by Spaceflight can be viewed on BMC Plant Biology website.
