Long periods in space can be detrimental to human biology, but it wasn’t exactly known how the lack of gravity affected plants. A new study suggests that space doesn’t seem to affect certain aspects of root growth.
The scientists published their findings in the journal BMC Plant Biology. In 2010, researchers sent petri dishes loaded with seeds to the International Space Station, where astronauts tended growth experiments on the plants. The first involved monitoring root development. The researchers measured how roots “waved” (how the root tip wandered through a small circle over the course of a 24-hour period) and “skewed” (began growing at an angle when it touched a surface) every 6 hours during the first 15 days of growth. The plants were two strains of Arabidopsis.
Previously, earthbound studies suggested that these traits were genetically determined, but that gravity also played a major role in waving and skewing. The new findings reveal otherwise. In general, seedlings grown in orbit were smaller but they exhibited the same degree of waving in strains grown on Earth. The root tips of space-grown plants showed a tendency to skew a bit more than the ones that grew on Earth when they encountered an object. This was mostly due to the larger number of cells.
Reference: “Plant growth strategies are remodeled by spaceflight” by Anna-Lisa Paul, Claire E Amalfitano and Robert J Ferl, 7 December 2012, BMC Plant Biology.