I lost the post on GUS expression in pollen, but I would recommend that you
look up Baker, SS, KS Wilhelm & MF Thomashow (1994) The 5'region of
Arabidopsis thaliana cor15a has cis-acting elements that confer cold-,
drought- and ABA-regulated gene expression. Plant Molecular Biology 24:
701-713. Transgenic RLD with a cor15a promoter fragment fused to
GUS gave expression in the pollen, while nontransformed RLD did not.
We didn't check the RNA levels of the endogenous gene in pollen, however
(it wasn't our main interest). I hope this helps, but I do think this control
(of checking nontransgenic plants) really should've been done for the
experiment in question.