From: "Randall M. Story" story at caltech.edu> on 2002.06.05 at 18:44:18(8960)|
Thanks for your response. I guess my question is in some sense whether
bulbils are essentially masses of generic "tuber tissue" that form on
leaves. If so, then they could simply grow by "reprogramming" leaf tissue
to form "tuber tissue" so as to form what is more or less a tumor on the
leaf. Some pictures I have seen of bulbils seem to look like this,
superficially at least. Then if such a "tumor" is planted, it might develop
the complete range of cells necessary for growth. Such a simple switch in
cell type is easy to imagine developmentally, much more simple than somehow
creating a "real" tuber (presumably with a range of specialized cells) on
the leaf. Just speculation on my part...
Or maybe cells that will eventually form bulbils have already specialized by
the time other leaf cells have specialized???
Are there any guesses as to whether the common ancestor to Amorphophallus
had a bulbil making ability that was lost in most of the other guys, or
whether it was an "invention" in only a few species? (molecular
phylogeneticists in the audience??). If it was lost in the majority of
species, they may still have some sort of latent ability to do this, even if
it is some sort of specialized structure instead of just some tumor-like
mass of cells.