Credit: Roy Kaltschmidt

Soybean is the most recent addition to the rapidly growing list of crops for which a high-quality draft genome is now available. Writing in Nature, Schmutz et al.1 report that the 1.1-gigabase soybean genome—the largest shotgun-sequenced plant genome—is predicted to encode 46,000 genes. Two genome duplication events are likely to account for the observation that ∼75% of these genes are found in multiple copies. Although the importance of soybean as a source of protein and oil alone testifies to the potential implications of understanding its genetic makeup, this genome will also serve as the reference for ∼20,000 leguminous species that play a critical ecological role through their unique ability to fix nitrogen with the help of rhizobial bacteria. Availability of the genome should accelerate the association of quantitative trait loci of nutritional, economic and ecologically important traits with the causal DNA sequences from soybean in the near future. In the longer term, the genome will likely also be leveraged to improve the way in which a range of leguminous subsistence crops are used to both replenish soil nitrogen through crop rotation and meet the expanding needs of developing nations for protein and energy.