As I am going to be doing an internship in crop genetics next week, I thought I would explain a little about the further work on creating a genetically modified organism using data similar to what I will be collecting in summer. This is an extract of an essay I have previously written on the subject.
We know very little about the genes required to enhance yield, have tolerance to drought, flooding and other stresses.
Simply identifying the gene required is not enough, research must be undertaken to understand the interaction between genes, such as the multiple genes with several changes that are required for crops to be able to withstand global warming. This discovery needs to take place before any GM methods can be implemented.
Once the desired gene has been isolated, and cloned into a suitable bacterial vector then, a promoter sequence needs to be added to the gene of interest to ensure that it will be correctly expressed in the right place and then recognised by the rest of the sequence.
The method that makes transgenic plants, is the most commonly used, Agrobacterium-mediated transformations, and involve taking the Ti plasmid from an Agrobacterium tumefaciens bacterium that has a large TDNA section, named because it transfers its DNA into the host, which is cut with a restriction enzyme. This cut Ti plasmid is then incubated with the allele of interest that has complimentary “sticky ends” to the restriction site. This then forms a recombinant Ti plasmid, it is this which is introduced to the plant cells in a culture and the plant grows with this new feature from the allele.
Another method of gene transformation into plants is the micro injection method using a “gene gun” that injects the cells with DNA particles coated with the desired gene and bombarding the cells with this. The plant chromosomes are then integrated with the desired genes and the cells multiply to form a plant with the new features.
Intern Rachel 