Plant Genome Bolts Beyond Human Draft

MADISON, WISCONSIN--As champagne corks popped today in Washington, D.C., over news that the human genome has been almost completely sequenced, researchers here quietly learned that their favorite plant's genome is even further along.

The wispy, ankle-high mustard plant called Arabidopsis serves as a model system for plant biologists. As of Saturday, 108 million of the plant's 120 million nucleic bases had been sequenced and made publicly available, announced Athanasios Theologis of the University of California, Berkeley, at the International Conference on Arabidopsis Research. With some 90% of the sequence already finished, in polished form, the five international groups involved aim to have the whole thing completed by the end of July, well ahead of the original 2004 target date.

Funders and sequencers boast that the Arabidopsis genome is extremely accurate, with only 1 error for every 20,000 bases, says Theologis. Unlike the current drafts of the human, fruit fly, and other genomes, the Arabidopsis genome contains few gaps. Says Theologis, "it's probably the best done of all genomes."

Although Arabidopsis's five chromosomes are a fraction of the human set, the completed sequence will represent another scientific milestone as the first detailed genetic record of a plant. But as John Quakenbush, a researcher with the Arabidopsis group at The Institute for Genomic Research in Rockville, Maryland, puts it, "nobody eats Arabidopsis." The practical payoff will come as its sequence is used as a template for sequencing the four times larger rice genome, he says, which is expected to be completed in the next 3 years.