Date: Mon, 23 Nov 1998 08:38:03 -0500 From: "Mellard, David" <dam7@cdc.gov> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3690$foo@default> Subject: RE: genetics
> > factors, that is, other genes that can influence the color of a pitcher
> or
> > flower, and whether or not that comes into play when it comes to
> anthocyanin
> > production. My impression is that it is a factor because of the varying
> > degree of anthocyanin production (that is, the variation in the redness
> of a
> > plant) in plants.
>
>
> Dear David,
>
> Perhaps because there is more than one type of anthocynin produced
>in most plants? So that to create a antho-free plant you need two
>broken genes from both parents that would have coded for a chemical
>needed to create any anthocynins. Other plants may have genes which
>do code for this, but don't have genes that code for all the possible
>anthocynins and there for show less red.
My head is starting to spin, too, on this one since I'm dealing at this
point with conjecture based on a few basic genetic principles learned a
really long time ago.
The permutations seem dizzying. I wish I could remember in more detail the
recent article in one of the cp magazines about anthocyanins. My guess is
yes there are different anthocyanin compounds made and more than likely they
share part of the anthocyanin pathway together. It seems reasonable to
assume that a mutation early enough in the pathway will stop production of
all anthocyanins and that a mutation later in the pathway after it has split
to form a particular anthocyanin will stop production of that anthocyanin
but not all anthocyanin. That may account for the various shades of red
that one sees. I have the feeling, though, that it's more complicated than
that. Another explanation for the shading could be the amount of
chlorophyll that's produced remembering that in deciduous trees we only see
color after the chlorophyll vanishes in fall.
> Infact I think I just realized this is why some S.leucophylla
>have red in the leaves, but yet have yellow flowers. In normal
>plants, the flower don't get as many anthocynins (This is most likely
>true, since all the flowers on S.leucophlylla I have seen are *not*
>the same color red as what seen on the leaves. The petals often appear
>orange-red, while the leaves are a much darker red, where they are red.)
>as the leaves and when one set of the genes which code for anthocynins
>doesn't work, either the whole plant will be less red, or red will be
>missing from one, or some parts of the plant where it is normally found.
I agree, the amount of anthocyanin production is also another explanation
for the degree of redness.
Are there any real plant geneticists out there who can guide us. It's just
not wise to let a mammalian toxicologist muse with abandon on plant
genetics. But, it is a subject I enjoy and just can help musing about in
the lack of a real authority <gr>
David
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