Insertion into crop plants

Figure 3. Examples of desirable genes to be inserted into crop plants. A. Unrelated organisms may have genes beneficial to crop plants. B. Suggested extension of a biochemical pathway in plants. Bacteria produces desired molecule E by enzymatic steps Ej to E4 plant pathway stops at intermediate C. Introduction of bacterial genes for steps E3 and E4 causes plant cell to produce E.

By genetic engineering, a soil bacterium Bacillus thuringienis or BT) has been modified to produce pesticides that are more toxic than natural ones. The modified genes have then been inserted into crop plants to create crops that synthesize their own pesticides. There is Bt corn with a toxin that destroys the European corn borer and other pests, and there is Bt cotton protected against the cotton bollworm and the budworm. 

Transgenic plants are those plants in which functional genes have been inserted in their genomes. With advances in recombinant DNA methods and transformation procedures, it is possible to transfer genes into crop plants from... 

The advent of new capabilities in biotechnology forecasts another quantum leap as the capability grows to insert genes into crop plants The present prominence of Bacillus thuringiensis (BT) might suggest that the natural products chemist can be dispensed with, but it can be anticipated that pests will develop resistance to BT sooner or later Therefore, the biotechnologist apparently will have to rely on the chemist to identify other systems to express It thus appears that there is a future for the natural products chemist ... 

For example, in the case of Bt-corn, a gene from a naturally occurring soil bacterium. Bacillus thuring-ensis, was inserted into corn to provide resistance to the corn borer. The gene from the bacterium produces a protein, Bt delta endotoxin, which kills the European and southwestern com borer larvae. Bt-com eliminates the need to spray insecticides to control com borers. Although planting these crops reduces the amount of pesticides released into the environment, the long-term effects of Bt-com on human health and the environment are not known. 

In April 1982, before crops were planted, the drill rig was used to collect water samples from spots directly beneath the growing area of Field 5. A 30-cm metal well point with stainless-steel screen welded to the end of a section of hollow-stem auger was drilled to various depths below treated areas. Water samples were withdrawn through Teflon tubing inserted down the hollow stem into the point using the peristaltic pump. Sediment-free samples were bottled and stored for analysis as previously described. 

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