plastids in pollen

Stephen M Jankalski CEREOID at prodigy.net
Wed Oct 13 13:17:37 EST 1999


I believe you essentially have the scenario backwards. Its the pollen
grains that typically have plastids excluded during their development. For
practical reasons, pollen needs to be light weight and the excess baggage
(plastids and mitochondria) are eliminated during the formation of the
microgametes. The plastids and mitochondria are retained in the
macrogametes.

Kathleen Archer <Kathleen.Archer at trincoll.edu> wrote in article
<3.0.1.32.19991013105816.00698d0c at mail.trincoll.edu>...
> All plant cells contain plastids.  Even epidermal cells, which do not
> contain *chloroplasts* and are not green, do contain plastids.  Plastids
> are essential for far more than just photosynthesis, carrying out a ton
of
> other metabolic activities including amino acid synthesis, lipid
synthesis,
> various steps in the production of secondary products, etc.
> Pollen grains do contain plastids, but there are various mechanisms for
> excluding them from the egg.  I believe that some microgametophytes may
> exclude them from the pollen tube itself, so that sperm nuclei are
> delivered without plastids nearby.  There are other exclusionary
> strategies, but I can't remember the details on how they all work.
> Kathleen Archer
> 



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