Modify the hardness of cereal grain.
Puroindolines are lipid-binding proteins from wheat flour. Whether wheat is classified as hard or soft is based on the texture of the grain and ultimately determines milling and end-use characteristics. Puroindolines are responsible for much genetic variation in texture.USDA-ARS scientists have developed a way to modify the texture of grain by genetically introducing specific puroindoline protein genes or anti-sense nucleic acid constructs to cereal plants, such as wheat, oats, rye, corn and rice. Grain texture is particularly important when optimizing the quality of end products, such as flour and foodstuffs. Grain texture also dictates differences in taste, water absorption and milling characteristics.
Puroindoline proteins control the hard or soft texture of wheat, which is the only crop that currently can have its grain texture modified through conventional breeding. However, conventional breeding can result in other problems--reproductive incompatibility by the parent plants and the need to use more inputs to produce a hybrid plant. The ARS approach can modify texture in both transgenic and progeny plants.
Adding puroindoline genes to the genome of a cereal plant enables the grain texture to become softer than its parent. Conversely, when puroindoline genes are blocked in wheat, the grain texture becomes harder than the parental plant.
This approach uses standard techniques for cloning, DNA and RNA isolation, amplification and purification. It is a more efficient way to tailor grains for specific end uses, such as pasta, cookies and cakes. Those who could harness this technology: the processing and baking industries, as well as companies engaged in the development of transgenic plants and seed.
Note that the USDA-ARS Western Wheat Quality Laboratory has established a puroindoline genotype database as a service to wheat researchers, breeders and the public. Two tightly linked puroindoline genes, puroindoline a (Pina) and puroindoline b (Pinb), control most of the genetic variation in wheat grain texture.
Further information. Craig Morris, USDA-ARS Wheat Genetics, Quality Physiology and Disease Research, Room E202, Food Science Building, Washington State University, Pullman, WA 99164; phone: 509-335-4062; fax: 509-335-8573; email: morrisc@wsu.edu.
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| Publication: | Emerging Food R&D Report |
|---|---|
| Date: | Jul 1, 2008 |
| Words: | 337 |
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