Science Authors Sequence Rice; Offer Hope for Relief of Hunger

Every day, 24,000 people die from hunger and related causes, and 800 million people go to bed hungry. As the human population expands and farmland shrinks, food shortages--brought on by drought, political unrest, poverty or other complex reasons--are expected to become increasingly acute.

With the sequencing of two strains of rice, published in Science on 5 April, two groups of researchers -- one from the United States and one from China -- offer renewed hope for answering the growing demand for rice, a staple crop for more than half the world’s population.

The genetic code behind rice, "will speed improvements in nutritional quality, crop yield and sustainable agriculture to meet the world's growing needs," said Donald Kennedy, editor-in-chief of the journal, Science, published by the American Association for the Advancement of Science (AAAS).

Surprisingly, rice may be far more complex than scientists ever guessed, densely populated with many small genes--perhaps even more genes than the human genome. The rice genome may also provide a low-cost roadmap for investigating similar cereal crops such as maize, wheat and barley.

Rice, known scientifically as Oryza sativa ("or-EYE-za sah-TEE-va"), is the principle source of calories for over a third of the world's population. The rice strain, indica, sequenced by Jun Yu of the Beijing Genomics Institute and the University of Washington Genome Center, with colleagues at 11 Chinese institutions, is a major subspecies in China and other Asian-Pacific regions. Crossing the indica strain with another variety produces a super-hybrid with a 20- to 30-percent higher yield per hectare than other rice crops.

A second team, led by Stephen Goff and colleagues at Syngenta, studied the japonica, or Nipponbare subspecies, prevalent in more arid regions. Rice with higher vitamin content may result from the Syngenta research, Goff said: The japonica genome should reveal the gene responsible for Beta-carotene biosynthetic pathways, which facilitates Vitamin A production. Genetic information about rice may also set the stage for hardier, more pest-resistant crops, and help improve the cereal's usefulness for brick construction, water filtration and various other uses, he added.

The indica sequence, accessible at GenBank, and the japonica sequence, accessible through Syngenta and in escrow with Science, will help scientists further genomics research and, ultimately, improve the global food supply. A new AAAS agreement, Electronic Information For Libraries (EIFL), will make information published in Science freely available to regions where it is likely to do the most good. Under the EIFL agreement, non-profit organizations in 41 of the world's poorest nations will receive free access to papers published in Science.

For more information on the sequencing of the rice genome, see related articles on the indica sequence and on the japonica sequence.

--Lisa Onaga