Scientists from the University of Nottingham and Shanghai Jiao Tong University have made significant strides in understanding how the plant hormone auxin directs root growth towards gravity, a process known as gravitropism. Their research demonstrates that auxin activates a specific gene that reinforces cell walls on the lower side of roots, inhibiting growth in that area while allowing cells on the upper side to expand. This differential growth results in the bending of roots downward. The findings, published in Science Advances, also build on previous work linking auxin's role to the hormone abscisic acid, which affects root angles during drought conditions. This comprehensive understanding of auxin's mechanisms opens avenues for engineering crops that can better withstand environmental stresses.