Cutting Edge Technologies (1984) / Chapter Skim
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Biotechnology and Agricultural Research for Crop Improvement
Biotechnology and Agricultural Research for Crop Improvement
Pages 52-61
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From page 52... ...
During the last 50 years a better understanding of basic genetics and crop physiology has paved the way to dramatic increases in productivity of agricultural crop commodities via improved genetic and cultural practices (hybrid seeds, improved fertilizers, pesticides, and so forth)
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From page 53... ...
Location of DNA Within the Plant Cell The genetic information of a plant resides in three different locations within the plant cell. Figure 1 shows in a stylized way what an individual leaf cell might look like in a crop plant.
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From page 54... ...
CHOOSING A TARGET FOR BIOENGINEERING EFFORTS IN CROP IMPROVEMENT As was indicated earlier, plant cells contain tens of thousands of genes, each of which controls or influences a physiological process in the plant. At our present stage of research in molecular biology, we usually must deal only with one of these genes at a time.
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From page 55... ...
Another approach could entail finding the target site for a molecule that affects or regulates a specific metabolic pathway. Once we identify a key enzyme or target site, we can begin the process of using the tools of genetic engineering to change it.
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From page 56... ...
Advances in this aspect of biotechnology are needed and are certainly expected in the near future. BIOENGINEERING FOR HERBICIDE RESISTANCE: ONE EXAMPLE OF GENETIC ENGINEERING STRATEGIES Figure 2 delineated the general steps necessary for planning crop improvement via genetic engineering.
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From page 57... ...
into chemical intermediates involves many steps, each of which entails the movement of electrons along a chain of electron carriers (proteins with special functional cofactors) that are housed in the chloroplast membranes.
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From page 58... ...
Molecular Basis of Triazine Herbicide Resistance When atrazine-resistant weeds were discovered, several laboratories began investigating why the weeds did not die when this herbicide was applied. It was found that atrazine entered the new weed biotypes and was metabolized at low rates (unlike in the corn plants)
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From page 59... ...
The work is the result of a novel breeding program conducted by university scientists at Guelph, Ontario. The Guelph scientists had identified a new triazine-resistant biotype of the weed Brassica campestris (commonly called bird's rape)
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From page 60... ...
I anticipate the same success in the near future with potato and tomato and perhaps some other related crop plants. GENE TRANSFER VIA MOLECULAR TECHNIQUES The strategies for gene transfer outlined above (reciprocal crossing between cross-fertile weed and crop, and cell fusion to deliver weed chloroplast to crop plant cells)
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From page 61... ...
CONCLUSION It should be emphasized, in closing, that plant genetic engineering via biotechnology is a new and developing science that is going to supplement traditional agriculture. It will not replace standard methodologies for crop improvements, but it will add new facets.
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