Plants are aware of their “body” and endowed with proprioception (coordination of the body). They distinguish the top from the bottom. This constant search for balance creates a kind of spinning dance that makes the plant anything but still. You can see it in time-lapse movies.
Experiments of Darwin, Pfeffer then Israelsson and Johnson at the Lund Institute and carried out in space stations. Plants are aware of their “body” and endowed with proprioception (body coordination).
They distinguish the top from the bottom.
The roots (the last half-millimeter of the tip of the root) are attracted by gravity, natural or artificial (thanks to the statoliths, micro beads which move in the cell according to gravity, the equivalent of our inner ear).
In the stem, it is the endoderm which allows the plant to orientate itself towards the light and not towards gravity.