
Scientists Find Evidence of a
Common Genetic Key to Aluminum Tolerance in PlantsBy Hank Becker June 1, 2000Millions of acres of nonproductive land
may someday be transformed into amber waves of grain based on new genetic
research by Agricultural Research
Service scientists. That's because the scientists have found a gene in barley that makes plants
more able to withstand aluminum. A major component of soil clay, aluminum is
the third most abundant element in the Earth's crust. At neutral or alkaline
pH, it's not a problem for plants. However, in acid soils, the main form of
aluminum is highly toxic to plants. Aluminum toxicity can limit crop production on acid soils that cover well
over half the world's 8 billion acres of potentially arable land, including
about 86 million acres in the United States. When soils become acid, the toxic
aluminum damages plant root systems, greatly reducing yields on these soils.
One approach to reducing aluminum toxicity is to develop crop varieties with
increased genetic resistance to aluminum. ARS plant molecular biologist David
F. Garvin--working with plant physiologist Leon V. Kochian at the
U.S. Plant, Soil and Nutrition
Laboratory in Ithaca, N.Y.--identified genetic markers for a single gene in
barley that enhances aluminum tolerance. These markers can be used in breeding
programs to rapidly shuttle aluminum tolerance genes from aluminum-tolerant
barley varieties to aluminum-sensitive ones. Furthermore, the results of their study suggest that aluminum tolerance in
barley and its close relative, wheat, is due to the action of different forms
of the same gene. Since wheat possesses superior aluminum tolerance to barley,
it may be possible to genetically engineer increased aluminum tolerance in
barley by introducing a wheat aluminum tolerance gene. This research could provide insights into how some important grain
species--including wheat, corn and sorghum--can tolerate high levels of
aluminum in acid soils. Their findings are published in the May-June 2000 issue
of Crop
Science. ARS is U.S. Department of
Agriculture's chief research agency. Scientific contact: David F. Garvin, ARS U.S. Plant, Soil and
Nutrition Laboratory, Ithaca, N.Y., phone (607) 255-7308, fax (607) 255-1132,
[email protected]. U.S. Department of Agriculture |