The Vigna Genome Project

Genus Vigna consists of legume crops such as azuki bean as well as a number of wild species.  One of the most attractive features of the genus Vigna is the great adaptability of the wild species to severe environmental conditions including high salt (∼400mM NaCl), acid (∼pH3) or alkaline (∼pH10) soil, and drought (deprived of water for 1 month). By figuring out the mechanisms of how they adapt to such environments, it would be possible to generate novel crops tolerant to the stress conditions. However, there is few research basis of the genus Vigna established to date. Thus as a first step, we sequenced the genome of azuki bean to construct the reference genome sequence. We adopted three sequencing platforms, Roche GS FLX, Illumina HiSeq2000, and PacBio RS and obtained 140Gbp in total. Genome assembly consists of 8,910 scaffolds spanning 505Mbp (N50=612kb), which covers 92% of the azuki genome. We are constructing the genetic map using F₂ population derived by crossing azuki bean with its close relative to anchor the scaffolds on azuki’s 11 chromosomes. Meanwhile we carry out the genome annotation primarily based on the RNA-Seq and CAGE (Cap Analysis Gene Expression) data derived from 8 tissues and predicted 32,024 genes. In total genomes of 15 wild species will be sequenced and compared each other. All the data including genome and gene sequences, annotation, and comparative analysis, will be integrated into the Vigna genome database and opened to the public.