B1 Corn as GMO Essay Example | Topics and Well Written Essays - 1000 words

B1 Corn as GMO - Essay Example This cDNA strand is then isolated and cloned or duplicated for the purpose of transformation into another species and this transformation process is made possible with the help of the bacterium known as Agrobacterium tumefaciens (Peel, 2001). This particular bacterium infects specific woody dicotyledonous plant species, where certain parts of the Agrobacterium circular DNA known as Ti plasmid can insert themselves into the host plant’s cell (Peel, 2001). The host plant, which is the corn plant in this particular experiment, then expresses the Bt gene (Peel, 2001). If this particular transformation process is not opted for, then the gene gun can be utilized. The other transformation process is the use of gold particles and coating them with target genes, such as Bt genes in our example (Peel, 2001). Using a gene gun, the genes are shot into the single cells of the corn plant without the help of the Agrobacterium in a process known as particle acceleration (Peel, 2001). Now that the Bt genes are already incorporated into the corn plant, a series of tests should confirm the potency of the bacterial gene. Plant tissue culture is the next step. Individual cells of the corn plant are obtained for culture and are subjected to the transformation process, which basically involves the elimination of non-transformed cells using a method that involves the use of selectable marker genes (Peel, 2001). The cultured corn plant cells are then treated with herbicide or antibiotic, and whole corn plants called Bt corn plants are then grown from the seeds of those cultured cells that eventually survive (Peel, 2001). If the Bt corn plant expresses the trait even after several generations using laboratory techniques, then it is believed to be stable and can now be bred using conventional agricultural methods and the final test would be for it to be able to stand environmental conditions (Peel, 2001). The process of transformation of the corn gene into the Bt corn gene involve s a crucial intermediate step where, before the Bt gene is inserted into the corn plant, it is first modified with promoters that would later on be recognized by the corn plant itself (Peel, 2001). This step and particularly these promoters is most crucial to the development of the toxic properties of the Bt corn plant. Because of these promoters, Bt corn â€Å"encodes crystalline proteins from the bacteria that are responsible for larvae toxicity† (Peel, 2001). Upon the Bt corn being eaten, these crystalline proteins, or Cry proteins, will bind to the insect’s midgut and cause a water imbalance that will eventually burst the cells and kill the pest (Peel, 2001). There are currently two types of promoters used in developing the Bt corn plant – the CaMV35S promoter and the PEP carboxylase promoter. The former expresses the toxicity of the Cry proteins in all plant tissues including the photosynthetic parts as well as the ears, roots and tassels, thus killing all insects that subsist on any part of the plant (Peel, 2001). On the other hand, the PEP carboxylase promoter, due to its exclusive affinity to cells that actively manufacture photosynthetic proteins, expresses the toxic properties of the crystalline proteins only in the photosyntheti