Sequencing the Gene Space of Brassica rapa

Abstract

The Brassicaceae includes some of the world’s most important dicotyledonous crop species, including vegetables, forages, condiments, and oil crops. Among the Brassica crops, Brassica rapa is considered as an excellent model for genomic research on the Brassica species. B. rapa has a relatively compact diploid genome, a large collection of cultivars, and a broad array of available genomic resources. Because of these desirable features, there is growing consensus that B. rapa is an ideal candidate to act as a reference species for Brassica genomic studies. Already, various genomic studies have been conducted, including the construction of a BAC-based physical map, >150,000 expressed sequence tags, and ongoing genome sequencing. Sequencing and comparative analysis of the selected seed BACs have suggested that the triplicated B. rapa genome contains only approximately twice the number of genes in Arabidopsis. The imminent B. rapa genome sequence will offer novel insights into the organization and evolution of Brassica as well as the similarities and differences between the genomes of A. thaliana and other plant model species. In parallel, the transfer of knowledge from B. rapa to other Brassica crops is highly expected.