Rice is the most important staple food crop which feeds over half of the world population. It also has emerged as a reference plant for monocotyledonous species including many cereals due to its desirable attributes as a model crop: relatively compact genome size, well annotated genome, abundant functional genomics data, and well-established methods for genetic transformation. In addition, genome-scale libraries of targeted loss-of-function or gain-of-function mutants have enabled functional analysis of rice genes.