https://doi.org/10.1093/jxb/erz027
In this paper, we study the plant gravitropic response to transient inclinations at the organ scale and the associated motion of statoliths at the cellular level. Unlike previous observations in microgravity, the response appears to be independent of the level of gravity, with a response time much longer than the duration of statolith sedimentation. This observation implies the existence of a memory process in the gravitropic signalling pathway, independent of statolith dynamics. By combining this memory process with statolith motion, a mathematical model is built that unifies the different laws found in the literature and that predicts the early bending response of shoots to arbitrary gravi-stimulations.