It goes well with beans, rolls tightly around sushi and is a fluffy grain that soaks up the sauce from Brazilian, Asian and Indian dishes.
Rice has been a staple for more than 10,000 years, feeding millions of people all over the world, particularly in Asia and Africa. Now, teams of scientists from around the globe, including the University of Arizona, have unlocked the plant’s secret of life — mapping and sequencing its genome.
The accomplishment was announced in today’s publication of the scientific journal Nature. It marks the first step in a coordinated humanitarian effort by scientists in 10 nations to learn more about rice and its relatives, such as corn and wheat, so they can develop crops that endure harsh weather conditions, yield more grain and feed more people.
The development also is the first time that the genome — the genetic blueprint — of a crop plant has been fully mapped and sequenced. Previously, scientists had only drafts of the plant’s makeup that gave them a rough idea of what it might look like.
Scientists at 32 institutions taking part in the massive, seven-year effort focused first on rice and not other grains because it is widely eaten in countries such as India and China, where 80 percent of the world’s rice is grown and where the population is rising at an astounding rate.
Agricultural experts monitoring the population growth worry that farmers eventually won’t be able to keep pace, leaving some people at risk of starvation or disease.
"The poorest of the poor are the ones who depend on rice the most," said Rod Wing, a UA plant scientist who led a team at the university in its part of the project.
Worldwide rice production must increase 30 percent in 20 years to feed more than 4.5 billion rice consumers, analysts project.
"We’ll have to do it with less land, less water and poorer soil," Wing said.
Wing and his team laid the groundwork to sequence the genome of the rice species, Oryza sativa, an Asian type that is quite common.
The UA team broke the rice genome into fragments and then cloned them, Wing said. The team shared the clones with other participants in the international consortium, which sequenced them, identifying chromosomes.
Researchers from Britain to Taiwan pitched in. The joint effort revealed the rice genome has 12 chromosomes with about 37,500 genes — nearly 7,500 more than the human genome.
Wing said finding those chromosomes is "almost like finding the scrolls in the desert and translating and making them into a book."
Scientists want to figure out which genes control certain traits of the plant. For example, they hope to find the gene in an African species of rice that helps the plant survive drought. They’ll achieve this by experimenting with the plant’s genetic makeup.
Soon, researchers will begin to breed or genetically engineer the rice plants to improve resilience, boost productivity and strengthen their nutritional value.
Critics have complained that few genetic advancements in crops are available to poor countries that could stand to benefit. Those countries do not have the money to cover costly licensing fees that would pay for use of the patented technology.
Wing said the international consortium, led by Japan, was set up to clear that hurdle. The group aims to make its developments publicly available, so that all nations — poor and developed — can benefit. The research is supported by the Rockefeller Foundation, a philanthropic organization endowed by John D. Rockefeller.
Some companies that own the rights to genetic advancements are helping with the effort. Syngenta, a major company in crop development, donated drafts of the rice genome in 2002, which helped speed up the sequencing.
Scientists will focus next on completing the genome of corn, and later, its distant relatives: Wheat, barley, oats and sorghum — all staple foods related to rice.