Introduction To grow straight and upright, plants need to control actively their posture through tropic movements. Gravitropism has long been considered as a major feature of this postural control. However, mathematical modeling approaches demonstrated that the dynamics of the tropic movement and the final shape of the plants organs are actually the result of a conflicting control by (1) graviperception, that tends to curve the plants organ toward the vertical, and (2) proprioception (the sensing by the plant of its local curvatures), that tends to counteract this curving-up movement and straighten the organ [1, 2, 3, 4, 5]. Methods Here, we will describe original experimental devices developed in our laboratory, which we use in combination with image analysis and model-associated phenotyping [6]. Results They allow us to (1) quantify graviperceptive and proprioceptive sensitivities, and (2) identify as yet uncharacterized proprioceptive structures and cellular motors driving straightening movements. By detailing the example of the gravitropic response of Arabidopsis floral stem – which involves differential growth- and of poplar stem – which involves the formation of tension wood - to tilting we will show how such approaches can lead to new and original knowledge in plant biology. Moreover, we will explain how such approaches can benefit from space experiments.