January 28, 2009

Scientists Sequence Genome Of Biofuel Crop Sorghum

Researchers at Rutgers University have deciphered the genetic make-up of sorghum, a drought-tolerant crop and important food and biofuel source, Reuter's reports.

Scientists believe such a breakthrough could eventually help produce better food crops for arid regions with rapidly expanding human populations, such as West Africa.

Capable of thriving in hot and dry conditions, sorghum is one of the world's leading cereals, along with corn, wheat, oats and barley.

The plant's genome, which includes about 30,000 genes, was mapped entirely by an international scientific team that published the finding in the journal Nature on Wednesday.

The researchers are hopeful that the results might lead to ways of creating even more drought-tolerant types while providing a blueprint for developing, through breeding or genetic engineering, improved forms of other crops such as corn.

Last year, Molecular biologist Joachim Messing of Rutgers University, told Reuters of the amazing ability of Sorghum to thrive in the oppressive, drought-ridden soil at a farm in Mozambique.

"You should have seen the maize (corn) growing there, how poorly it did, and then see sorghum just across from it standing tall and green and resistant to disease and drought."

The researchers said that transferring some of sorghum's traits to corn could improve its value as a food and biofuel crop, as the plant is so closely related to corn.

In parts of Africa and India, a variety called grain sorghum is a common food source, and a separate variety called sweet sorghum has a stem similar to sugar cane.

The Food and Agriculture Organization of the United Nations has introduced sweet sorghum in China because of the country's interest in having a biofuel crop and its ability to grow in areas where corn would not.

Brazil's extensive biofuel economy is based on sugar cane and is regarded as the most productive biofuel crop in the world.

Experts say sorghum is a superior biofuel source to corn considering the entire plant can be used, rather than just the grain. Grain sorghum uses a third less water than corn to produce the same amount of ethanol per bushel.

"We now will have a better idea of how many properties of the grasses, such as drought resistance, sugar in the stem, or grain productivity are encrypted in their genes," Messing said.

"Knowing this may enable us to laterally move these genes around among these crop species, to customize them based on the needs of geographic location and climate."

Anna Palmisano, the U.S. Department of Energy's associate director of science for biological and environmental research, called the new discovery an important step on the road to the development of cost-effective biofuels made from non-food plant fiber.

"Sorghum is an excellent candidate for biofuels production, with its ability to withstand drought and prosper on more marginal land," she said.

She believes the fully sequenced genome would be an indispensable tool for researchers seeking to develop plant variants that maximize these benefits.

Around 60 million tons of sorghum is produced annually, far less than the other major cereal crops.


Image Caption: Bicolor sorghum also known as grain sorghum. Credit: Mississippi Genome Exploration Laboratory


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