Question
How does Roundup kill weeds, and how does GMO corn survive Roundup?
How does Roundup kill weeds, and how does GMO corn survive when Roundup is applied?
Submitted by: Flyboy
Answer
Expert response from Community Manager
Wednesday, 11/03/2015 17:53
Many questions on Roundup® have been answered in great detail on this site already, and if you would like to explore these in more detail, I have included additional links at the end of this response. Similarly, I invite you to the new Monsanto Company website dedicated to Roundup® and glyphosate.
Glyphosate specifically inhibits an enzyme, EPSPS (most growing plants produce this protein) that is essential to plant growth; this enzyme is not found in humans or animals. When sprayed with Roundup® - or any herbicide that contains glyphosate as the active ingredient- these plants will not synthesize certain aromatic amino acids required for growth. The end result is that these plants will die and thus not compete for the resources on a farmer’s field with crops. Plants that are tolerant to glyphosate contain a gene that codes for a version of this EPSPS protein that allows the plant to synthesize these amino acids resulting in normal plant growth.
Here are the basic steps describing the process of GMO corn:
1. Identify a gene that will provide resistance to the herbicide (CP4 EPSPS).
2. Based on the sequence of the resistant gene, make a corn gene that contains a promoter to turn on the gene, the resistance gene, and a sequence to stop gene transcription.
3. Transform the plant in tissue culture to incorporate the resistant gene.
4. Screen for plants that have successfully incorporated the resistant gene, in fact tolerant to glyphosate and contain no apparent unintended effects.
A very good detailed description of the process is already available here.
Here are other questions and responses on Roundup® and Roundup Ready® products:
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