Genome Sequence of Castor Bean

Abstract

Castor bean (Ricinus communis) was the first plant species with its genome sequenced in the spurge family which also includes cassava, rubber tree, and physic nut. Castor bean is a unique plant species because the seeds are a primary source for the natural product castor oil that contains an unusual fatty acid of economic interest, as well as ricin, the world’s deadliest toxin to humans. A draft version of the castor bean genome has been produced using a conventional clone-based and paired-end sequencing approach that reached a sequence coverage of 4.6-fold. Based on the genome sequence assembly, members of the ricin gene family and key oil synthesis genes were identified in a comprehensive manner, representing an important resource for future trait improvement. Importantly, comparative genomics analysis of the castor bean genome with other dicotyledonous plant genomes supported the presence of a conserved ancient hexaploidization event shared throughout the dicot lineage.