Q: inducible promoters for plants
ashendel at aclcb.purdue.edu
Thu Feb 6 10:33:34 EST 1997
On Mon, 03 Feb 1997 08:09:33 +0100,
Dr. K. Eimert <eimert at geisenheim.fa.fh-wiesbaden.de> wrote:
>I am in need of an inducible promoter for plant transformation. It is
>important that this promoter would not "leak" if not induced, e.g., the
>hs-promoter would not work for us.
We are just starting a project with this, and have chosen to start
with the tet-derepression system from Christine Gatz, Univ. Bielefeld.
See Meths. Cell Biol. 50:411-424, 1995. I can't report on its
leakiness, but she claims 500-fold induction
My experience with inducible systems in is mammalian cells, where
the tet repressible system seems to be king in terms of tight
regulation. In general with inducible systems, the amount of basal
expression is related to the amount of induced expression. Zero basal
expression is essentially impossible. However, the fold-induction
varies with the systems and the specific stable line that is produced.
Most of the time, for stably transfected cells, 100-fold induction at
the mRNA level is very good, and much above 200-fold is rare. If you
need a low basal level, select a clone that has the level you desire.
It sounds a bit stange, but it really is a relative thing and
completely up to the investigator (and the relative toxicity of the
gene product to the cell).
Purdue University, West Lafayette, IN
ashendel at purdue.edu
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