I was thinking about the ions that migrate towards electrodes in solution. Two thoughts occur to me:
1. Will wiring a plant up with the anode on the aerial parts and the cathode in the soil cause an increased amount of negative ions to migrate out of the soil and into (and up) the plant? (Or the other way around if I have this arse-backwards, I haven't done any physics/electronics for years). If this is the case, then the direction of the current would be an important factor and should produce different results if varied, something that could be put to good use. There should be existing research on this and I'll post links as I find them.
2. If you run current through a solution (aqueous obviously) of an alkaloid salt, will the positive ions, in this case the alkaloid, migrate to the cathode? I think they would. If it forms crystals in its freebase form, then it should literally grow on that electrode! Of course in a dirty solution there would be all sorts of other crud attracted. I don't expect that you can throw a couple of wires into some pedro tea and pull them out with glistening crystals attached a few hours later. But I do wonder if it is worth a try. Surely this is something other people have tried before?