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Old 17-02-2004, 02:42 AM
J Fortuna
 
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Default wild to cultivated changes?

Pat,

Thanks for this info. I have been following this thread closely, though I
only understand some of it, but I wish I understood all!

One thought occurred to me after reading your statement:
If there is a protein that is in all flowers and only in flower tissue, we

could find
the gene associated with this protein and all flowering plants would have
this gene in their DNA. Problem is a non flowering plant could also have
this gene, but never turn it on.

So does this mean that there could be a plant somewhere out there that is
currently a non-flowering, purely-leafy plant, but if a descendent of this
plant turned on the flowering gene it might actually flower, and we might
get a completely new orchid species? I think I read somewhere that orchids
are mainly or only identifiable as orchids because of the flowers, and so I
am thinking that there could be a plant species out there that would be an
orchid if only it did flower but it never does.

Does this make sense, or should I just go back to open-mouthed lurker status
on the continuation of this fascinating thread?

Thanks,
Joanna

"Pat Brennan" wrote in message
...
Al, I hope the head ache is a little better and this does not make it much
worst. If this does, just remember I'm a farmer who is out of date (while
writing this I am referring to a book coauthered by Watson) and has
forgotten most of what I learned about this sort of stuff.

That being said, I think you are thinking on much to simple of terms. I
think it is a mistake to think in terms of flower templates just as I

would
not call a complex computer program a template. The making of a flower is
more a process with genes being turned on and off at different times and

the
various proteins produced interacting with each other.

A gene is a template for a protein. There is DNA transcription to RNA

which
is translated into a protein or an enzyme (which is itself a proteins).

At
the underclass level each gene is a template for a unique protein. If

there
is a protein that is in all flowers and only in flower tissue, we could

find
the gene associated with this protein and all flowering plants would have
this gene in their DNA. Problem is a non flowering plant could also have
this gene, but never turn it on.

A flower is probably composed of 100's of proteins (50 to 1000 is a good
guess, I do not know if counts have been made). To make a flower these
proteins must be made at the right time, in the right mix, and at the

right
place. I do not think anyone really has a grasp on how this is all
controlled, but I think people have played with gene precursors to affect
the number of petals produced on a flower.

When you are working in the lab with a piece of undifferentiated tissue,

one
hormone will cause it to grow into a plant while another will cause it to
grow into a flower. I think this fits into this discussion, but I am not
sure how or why.


Pat B