Plants can grow in space
It is possible to grow plants in the absence of gravity
Gravity is determinant for the development of plants, which are as they are thanks to it: with the roots underground and the stem up. But is it possible to grow plants in the absence of gravity? The answer is yes, but the biological keys that make it possible are not yet known.
In recent years, several experiments have succeeded in growing different species in space.
In 2016, NASA introduced the first flower -zinnias- grown on the International Space Station (ISS) and in August 2015 the American astronauts Scott Kelly and Kjell Lindgren and the Japanese Kimiya Yui tasted a “space lettuce”.
Within the “Seedling Growth” project, in 2013 and 2014 thousands of “Arabidopsis thaliana” seeds arrived in the ISS, a model plant most used in biology laboratories and with which this year we want to advance experimentation.
Thus, on June 1, 1,748 seeds of this plant will be sent to the ISS, within the SpaceX-11 mission.
This experiment (Seeding Growth-3) is the third and last of a series begun in 2013 to determine the effects of weightlessness on plants, and is the result of collaboration of scientists Europeans and Americans, told Efe Javier Medina, Of the Center for Biological Research and co-director of the project.
“Arabidopsis thaliana” is an herb with no apparent human interest and evolutionarily related to cabbage, turnip, radish or mustard, Medina said.
It is used in research as the laboratory mouse in biomedicine and many data are known about it, as its complete genome; is easy to handle and cultivate.
Of the 1,748 Arabidopsis seeds that will reach the ISS in June, 420 will grow in zero gravity – microgravity – another 420 in gravity 1 (Earth’s) and 908 in gravity 0.3 (Mars).
The seeds will hydrate in the Station and germinate giving rise to small plants (seedlings) that will grow during six days. Later they will stop their growth and will be preserved to analyze them on land, approximately one month later.
Evolutionarily, plants originated in the sea so the most important problem they had to solve to “colonize the mainland” was to develop rigid structures that would withstand the force of gravity without collapsing; In addition, the terrestrial plants “learned” to use the gravitational stimulus to establish the direction of its growth, Medina said.
But the plants also grow without gravity and now the goal is to understand how, although the first experiments with “Arabidopsis thaliana” already point to a possible explanation.
There is an adaptation process of which, although its biological mechanisms are not yet known, causes the stimulus of gravity to be replaced by another one of “equal power”.
“Our hypothesis is that light and particularly red light can contribute decisively to this process, but we need to know how and when it is triggered and adaptation occurs.”
What researchers already know is that plants grown in space show important changes at the cellular and molecular level in the early stages of development.
In an experiment carried out at the “Cervantes mission” at the ISS by the astronaut Pedro Duque, it was shown, for example, that the proliferating root cells, on which the plant development program is based, were strongly altered in As well as the time it took to complete each cycle of cell division.
Medina stressed that the absence of gravity also represents for plants a stress comparable to that caused by drought, salinity, cold or heat: the experimental approach of our research has many points in contact with studies on the response of plants to Climate change.
“We are not studying climate change, but our research can help us learn more about the mechanisms of plant response and adaptation to stress conditions in general,” said the researcher, who also recalls that cultivating without gravity is essential. Support of human space exploration and to sustain human presence on Mars.