So, going by the rest of your response, even a seed is 'intelligent'.
It senses heat,light,nutrient,water, and as you have justly defended, gravity.
Gravity detection may be(or is) the leading sensation used by the seed until it reaches the surface. Does it remain the leading 'sense' after that?
A seed is capable of carrying out a biological program of expressing particular genes, devoting resources, and detecting directionality such that the cotyledons grow “up” because the start statholites settled “down”.
Directionality is established by the starch particles. Up and down are opposite sides of the same coin. If a plant can detect ‘down’ then the program has established (by which I mean “know”) which direction is ‘up’.
Gravitropism is just used to grow the cotyledons ‘up’ as far as I know, but like I said - one botany class, long ago; used to skip it sometimes for a midafternoon break with my girlfriend who didn't have class at that time.... pretty little thing.