BEIJING, TOKYO, AND WASHINGTON, D.C.--Two groups published their versions of the genome of rice today. One sequence comes from the rice consumed in China and most of Asia (the indica subspecies); the other is derived from the rice eaten in Japan and in temperate countries (the japonica subspecies). Heralded as a landmark achievement for agricultural sciences, these two efforts come from groups who are relative late-comers to rice sequencing. Yet they have pulled ahead of an international rice genome consortium.
Currently, the genome of just one plant, a laboratory favorite called Arabidopsis, has been fully sequenced. But during the past decade, researchers have become ever more interested in sequencing rice--in part because it is a staple food for half the world's population and in part because it can help plant scientists find genes in other cereals with larger genomes. The rice genome is about 4 times the size of the Arabidopsis genome, but many times smaller than the genomes of either maize or wheat.
In the 5 April issue of Science, Yang Huanming of the Beijing Genomics Institute (BGI) and colleagues describe a draft sequence of the indica subspecies, and Steven Goff from the Switzerland-based agrobiotechnology giant Syngenta and his team report a similar achievement for japonica. Both were able to complete these versions at lightning speeds because they used a sequencing method called whole-genome shotgun. In this approach, all the DNA is cut into small bits that are sequenced and then pieced together with supercomputers.