The average grain of rice is just 5.5mm in length and weighs less than half a gram. Yet, this small, unassuming substance feeds half the world’s population. In the next two decades, global consumption of rice is expected to increase by 30% to more than one trillion pounds annually. Maintaining high yields for this crop has proven to be a daunting challenge for some of the world’s poorest farmers, but that may soon change. An international team of researchers has just finished mapping the rice genome, and the first crop to be fully sequenced by genetic researchers may be one of the most important to humanity’s future.
Scientists from Japan, Korea, the U.S. National Science Foundation (NSF), the Institute for Genomic Research (TIGR), and the University of Arizona, to name just a few, took part in the International Rice Genome Sequencing Project (IRGSP.) The project was launched in 1998 but gained momentum in 2002 when two agricultural chemical companies, Monsanto and Syngenta, donated their own rudimentary findings on rice DNA to the project. The completed sequence was published in the journal Nature (August 11, 2005).
“Knowing the sequence of one of the world’s most important crops will be invaluable to plant genomics researchers,” according to NSF Director Arden L. Bernent Jr. “This project will potentially help millions of people around the globe.”
The group used the japonica subspecies of rice, consisting of 37,422 genes and 400 million DNA bases. By comparison, the human genome consists of 3 billion DNA bases but only 25,000 genes. “Much of the Human Genome Project has revolutionized biology. The rice genome promises to inspire new cereal crop research,” says TIGR President Claire Fraser. Researchers hope to use the data to isolate desirable genetic traits in the plant, such as drought tolerance and pest resistance. This, in turn, will allow farmers to grow rice more suited to particular regions and growth conditions.
Scientists will also use the rice genome findings to research the genetic composition of similar crops, such as barley, maize, wheat, rye, sorghum, and sugarcane. “Rice is the Rosetta Stone for crop genomes,” says Robin Buell, lead investigator for TIGR. “We can use the rice genome as a base for genomic studies of cereals.” According to Buell, the rice genome is collinear with various other cereal species, meaning that similar genes should occur in roughly the same order within their various DNA sequences. The new sequence map is one of the most accurate and complete for any multi-cellular organism. -Patrick Tucker
Sources: The National Science Foundation, 4201 Wilson Boulevard, Arlington, Virginia 22230. Telephone 703-292-5111; Web site http://www.nsf.gov.
The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, Maryland 20850. Telephone 301-795-7000; Web site http://www.tigr.org .
Originally published, THE FUTURIST, November-December 2005