Genetically Modified Canola

Canola (or rapeseed), Brassica napus, is an oilseed crop used in many foods such as margarines and cooking oil and seed meal (the fibrous material left after the oil pressing process), has a high protein content making it highly desirable as a stock feed.



Canola (Brassica napus)

Why is canola genetically modified?

the main purpose of genetically modifying canola plants is weed
control. Two genetically modified (GM) canola varieties have been developed in Australia, Roundup Ready® and InVigor®. These varieties of canola plants are resistant to specific herbicides. therefore increasing quantity and quality of the grain produced.

 

 

How is canola genetically

The technique used to produce the herbicide resistant crops is DNA recombination. GM canola line contains the cp4 epsps gene which causes the plant to have herbicide tolerance in the GM canola plants. The gene is derived from bacteria (Agrobacterium tumefaciens strain) CP4 and encodes 5-enol-pyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme of the shikimic acid pathway which is involved in the biosynthesis of plant phenolics.
In short, the GM canola plant contains a gene which will cause it  to be resistant to a specific herbicide from a bacteria. And this gene (cp4 epsps )will allow the plant to produce a protein (enzyme) and become resistant to a specific herbicide.

figure 1

How is the gene inserted into the plant? by DNA recombination where a restriction enzyme cuts out a desirable DNA fragment from the bacterias DNA (where the desirable gene is located in this case) and the same restriction is used to cut open a plasmid (as seen in figure 1), to ensure that the complementary sticky ends exist on the plasmid and DNA fragment. In GM canola, the gene for herbicide resistance is known as a transgene since its a gene that's been transferred from one organism (bacteria) to another organism (the canola plant). similarly to figure 1 the gene from the bacteria chromosome is inserted into a plasmid. the new gene is then transferred to a canola plant cells by the plasmid. Plasmids are used as they are able to pass through cell membranes. Promoters are DNA sequences that are required in order to allow RNA polymerase to bind and initiate correct transcription. The expression of cp4 epsps (the gene for herbicide tolerance)  in the GM canola line is under the control of a chimeric constitutive promoter. And once the gene is inserted the plant is able to produce the enzyme which will allow it to be resistant to herbicides

Bibliography:
http://www.ogtr.gov.au/internet/ogtr/publishing.nsf/Content/dir105rarmp-toc~dir105rarmp-ch1~dir105rarmp-ch1-s5
 http://www.dpi.vic.gov.au/agriculture/innovation-and-research/biotechnology/genetically-modified-crops/gm-canola
http://www.afaa.com.au/resource_guides/Resource_Canola.pdf