August 30, 2007

Aluminum tolerant sorghum seen to boost crop yields

Researchers in Cornell University in New York successfully cloned an aluminum-tolerance gene in sorghum which is seen to improve crop yields in developing countries that have problems with acidic soils.

Aluminum locks up in clay minerals and dissolves into soil as toxic in acidic soils, thus, making it difficult for crops to grow. Aluminum toxicity in acidic soils limits crop production in as much as half the world's arable land, mostly in developing countries in Africa, Asia and South America, the researchers said.

Cornell's research shows that in aluminum-tolerant sorghum varieties, special proteins in the root tip release citric acid into the soil in response to aluminum exposure. Citric acid binds aluminum ions very effectively, preventing the toxic metal from entering the roots.

Sorghum is an important food crop in Africa, Central America and South Asia and is the world's fifth most important cereal crop.

The cloned aluminum-tolerant gene in sorghum is expected to have new genetically-engineered aluminum-tolerant sorghum lines by next year.

The research, to be published in the September issue of Nature Genetics, provides information on how specialized proteins in the root tips of some cultivars of sorghum and other crops like wheat and corn can boost aluminum tolerance in crops.