This might be a big boost for the biotechnology sector. According to a Science Daily news article (http://www.sciencedaily.com/releases/2007/08/070827163025.htm), a team of Cornell University researchers have been able to clone a unique gene in sorghum responsible for making the plant aluminum-tolerant. This will be able to allow scientists to develop genetically engineered sorghum and other related crop species as early as next year that can tolerate aluminum ions in acidic soil that otherwise will make it impossible for ordinary plants to grow.
Soils that are too acidic make it possible for the element aluminum to dissolve into the soil and become electrically charged particles called ions. This makes it virtually impossible for plants to grow naturally. Aluminum toxicity in soil has limited the production of crops in as much as half of the world’s arable land. Aluminum toxicity is especially a problem mostly in countries such as Asia, Africa and South America.
For this reason Cornell researchers targeted cloning the gene in sorghum since it is an important food crop in different countries found in South Asia, Central America and Africa. Sorghum is also the fifth most important cereal crop in the world. The research done by the team of Cornell scientists headed by Leon Kochian, a professor of plant biology and director of the US Department of Agriculture–Agriculture Research Service (USDA-ARS) Plant, Soil and Nutrition Laboratory at Cornell, showed that aluminum tolerant varieties of sorghum make use of special protein in the root tip to release citric acid into the soil when exposed to aluminum in acidic soils. The citric acid binds effectively into aluminum ions and prevents the toxic metal from entering into the roots of the plant.
The team of Cornell researchers used genetic mapping to identify a single gene that encodes a certain membrane-transporter protein that is responsible for the release of citric acid on the root tips of the sorghum plant. The gene that they were able to identify is only activated in the special protein and release citric acid when it detects aluminum ions in the surrounding soil.
The researchers have initially used the newly discovered sorghum gene in genetically modifying wheat plants and also develop an aluminum tolerant small mustard plant species in the process of the research. The map-based cloning of this important gene in sorghum would help scientists in making the said plant a model for further discovering other mechanisms of aluminum tolerance in plants as well as find new ways of improving crop yields.
The research would also help a number of third world countries to someday improve crop yields on marginal lands that may highly acidic, making it difficult for current plant varieties to thrive. The research can also help someday improve food production worldwide by making best use of land by using genetically engineered plant crops to improve harvests.