GENTECH archive


Fw: Bt toxins

I received this reply from Prof Joe Cummins:
Turning to your question, all cells of the crop contain the gene for Bt
toxin, in virtually all of the cases, the gene is driven by the
cauliflower mosaic virus promoter. The amount of toxin in each tissue
varies but some is present in all. There is a plant promoter being
developed to replace cauliflower mosaic virus promoter, the plant
promoter is mainly active in the plants vascular tissue, but that
promoter is not yet commercial. Sounds like the claims above are for a
promoter that isn't used yet! standard PR stuff in biotech! Joe
Clive Elwell
-----Original Message-----
From: Clive Elwell <>
To: gentech <>
Date: Thursday, 26 November 1998 16:41
Subject: Bt toxins

Hi Everyone
I read this claim recently:
> Toxins used in transgenic food crops are plant-produced Bt
> toxins called cry" toxins and they can be modified for specific
> results, such as to kill only unwanted insects. Also, these Bt
> toxins are only present in plant foliage, not the grain
I have heard the opposite claimed, that the toxins are present in all parts of the plant. I have heard that "every mouthful of Bt potato contains a dose of Bt pesticide"
Where does the truth lie?
Clive Elwell