In the zero gravity conditions aboard the International Space Station, scientists get to play around with plant growth in ways not possible on Earth. NASA has strongly supported zero-gravity plant research since the beginning, given its crucial importance to any sustainable long-term space exploration.
Recent research from ‘Hydrotropism and Auxin-Inducible Gene expression in Roots Grown Under Microgravity Conditions’, or the HydroTropi experiment, promises to provide new insights into plant growth on a molecular level in response to water (hydrotropism) and gravity (gravitropism). Scientists are growing cucumber seedlings ‘in microgravity’ conditions, providing controlled levels of water to determine the magnitude of root growth responses. They are specifically looking at auxins, a suite of plant growth hormones that, when induced, stimulate cell division at a growing root tip. Understanding how environmental parameters such as water induce auxins in zero gravity will allow scientists to refine their understanding of plant gene expression and how to optimize plant growth in such an alien environment.