Genetic Engineering of Plants Agricultural Research Opportunities and Policy Concerns (1984) / Chapter Skim
Currently Skimming:
Applying the Tools of Biotechnology to Agricultural Problems
Applying the Tools of Biotechnology to Agricultural Problems
Pages 40-52
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 40... ...
They are working on increasing the nutritional quality of feed crops. They are also trying to engineer soil microorganisms that can be used to supply nitrogen to crop plants, or else mitigate or combat soil diseases.
|
From page 41... ...
Atrazine resistance arises from a mutation that alters that membrane protein so that it will no longer bind atrazine. The quinone, however, still binds to the altered membrane protein; consequently, electron transport remains undisturbed in the presence of atrazine.
|
From page 42... ...
It's a dramatic success story, and it didn't take one iota of genetic engineering." Unfortunately, an identical approach is not feasible with many crops, as few are cross-fertile with weeds. There are, however, many herbicideresistant weeds that are closely related to—but not cross-fertile with major crop plants.
|
From page 43... ...
Arntzen and others are investigating methods to induce this mutation. The most powerful technique, if it can be mastered, will be to transfer the resistant gene from a weed into a crop plant using recombinant DNA technology.
|
From page 44... ...
The increasing adoption of minimum or no-till farming practices provides an extra incentive for developing effective controls. Both of these practices leave organic debris on the soil surface, which makes the soil both wetter and colder creating a more favorable environment for pathogenic microorganisms.
|
From page 45... ...
Schroth, Department of Plant Pathology, University of California at Berkeley whether the introduction of resistance through gene-splicing would result in the same Toss in yield as does conventional plant breeding. The alternative genetic engineering approach is to harness and improve upon the beneficial microorganisms that inhabit some soils and use them to combat plant disease.
|
From page 46... ...
Finding such bacteria will be difficult, Pseudomonas colonizing the surface of a sugar beet root. This scanning electron micrograph shows chainlike colonies of bacteria against the ribbed background of a sugar beet root (x 3000~.
|
From page 47... ...
1 , . ~ ldentitying and improving rhizo bacteria will require the combined efforts of bacterial ecologists, plant pathologists, biochemists, and genetic engineers.
|
From page 48... ...
Farmers worldwide supplement the available nitrogen with some 60 million metric tons of nitrogen fertilizer annually. By the year 2000, an estimated 160 million metric tons of nitrogen fertilizer may be used each year.
|
From page 50... ...
These infection threads wind throughout the cells in the root nodule, providing a conduit through which bacteria migrate from one cell to another. Once inside the cells, the bacteria convert nitrogen to a chemical form the plant can use.
|
From page 51... ...
When the genetically engineered Agrobacterium infected an alfalfa plant, it induced root nodules and infection threads to form (bottom photograph, magnification x 7601. The genes for nitrogen fixation, however, were not expressed.
|
From page 52... ...
He suggested that molecular biologists work with plant breeders, agronomists, and pomologists in identifying scientifically and economically attractive projects for genetic engineering. "It will not be a simple task to improve productivity per hectare," he said.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.