Not sure how long ago you posted this or if you are still looking for an
My humble guess would be that the cells of the plant are unable to take up
the beta estradiol because the method of transport is active and ATP is
needed to do so. The sucrose supplies the energy needed to do this. Beta
estradiol is a steriod and steroids usually pass through cell membranes
easily. Like dissolves like. Perhaps because you are experimenting with a
plant cell which is surrounded by a cell wall maybe diffusion is prevented
or compromised unless it is actively pumped by the cell. Perhaps beta
estradiol is absorbed minimally through the small openings in the cell wall
but not enough to be perceived by your instruments.
Another guess would be that the steroid is too big and needs to be
transported in a vesicle? Is ATP needed to create a vesicle?... I'm not
If I am too late in responding and you all ready have a hypothesis I would
appreciate if you tell me what you finaly concluded.