2 Genetic modification of plant cells
Your answers to Activity 1 will have revealed that the initial development of commercial GM crops has focused on the introduction of two traits: herbicide tolerance and insect resistance. However, many other traits have been introduced into crops that have yet to be grown commercially on any scale. These traits include characteristics such as resistance to viral, bacterial and fungal infections, stress tolerance (for example to high levels of salt in the soil), changes to flower pigmentation, and modification of plant nutritional content. You will explore the current global state of play in an activity at the end of this unit, and it may be revealing to discover which, if any, of these traits have become commercially significant since this topic was written (2006).
At this point we will begin to explore how these transformations are carried out. Techniques that have been developed to modify E. coli cells to produce insulin can be built on, but transformation of plant cells provides unique challenges, as they are much more resistant to accepting foreign genetic material. Luckily, a naturally occurring soil bacterium, Agrobacterium tumefaciens, has evolved that overcome these challenges.