Corn line MON832 was developed through genetic modification to be tolerant to the glyphosate herbicide.<br>The modified corn line permits farmers to use the herbicide for weed control in the cultivation of corn.<br>A commercial corn line was transformed by particle gun acceleration technology using a DNA solution<br>containing two plasmids, PV-ZMBK07 and PV-ZMGT10. Molecular analysis of the resultant corn line,<br>identified as MON 832, established that the line contains CP4 EPSPS, gox and nptII genes and does not<br>contain the cryIA(b) gene. While the nptII gene was incorporated into the genome of MON 832 corn, it is<br>not expressed in the plant since its bacterial promoter is only active in bacteria. Western blot analyses have<br>confirmed that the nptII protein is not expressed in the modified corn plant. Segregation and stability data<br>were consistent with a single active site of insertion into the genomic DNA of line MON 832.<br>The CP4 EPSPS gene was derived from the soil bacterium Agrobacterium sp. strain CP4. The CP4 EPSPS<br>protein produced by this gene is highly tolerant to inhibition by glyphosate, and allows the modified corn<br>plant to be treated with levels of the glyphosate herbicide that control competing weed species.<br>The gox gene was cloned from Achromobacter sp. strain LBAA and was also inserted to provide glyphosate<br>tolerance. The GOX enzyme accelerates the normal degradation of glyphosate into aminomethylphosphonic<br>acid (AMPA) and glyoxylate. This provides an additional mechanism for the modified corn’s tolerance to<br>applications of the glyphosate herbicide.<br>Corn is a cultivated species with a long history of safe food and feed use. Animal feeding is by far the largest<br>use of corn with the majority of annual production fed to cattle, poultry, and swine. Corn is readily<br>consumed by livestock and because of its high starch-low fibre content. Corn does not normally contain<br>toxins or antinutritional factors. A significant quantity of corn is fed to livestock directly or in formulated<br>feeds. In addition to corn grown for grain, a portion of annual corn acreage is utilized as whole plant corn<br>silage with consumption confined almost entirely to ruminants. The low price and ready availability of corn<br>has also resulted in the development of large volume food and industrial uses.<br>Roundup Ready corn line MON 832 differs from its parental counterpart in the insertion of the<br>aforementioned genes, CP4 EPSPS and gox. The proteins encoded by these genes are expressed throughout<br>the plant tissue and throughout the life of the plant.