Efficient insertional mutagenesis in rice using the maize <i>En</i>/<i>Spm</i> elements

<jats:title>Summary</jats:title><jats:p>We have developed a novel system for insertional mutagenesis in rice (<jats:italic>Oryza sativa</jats:italic>) based on the maize (<jats:italic>Zea mays</jats:italic>) enhancer/suppressor mutator (<jats:italic>En/Spm</jats:italic>) element. In this system, a single T‐DNA construct with <jats:italic>Spm</jats:italic>‐transposase and the non‐autonomous defective suppressor mutator (<jats:italic>dSpm</jats:italic>) element is used in conjunction with green fluorescent protein (GFP) and <jats:italic>Discosoma sp.</jats:italic> Red Fluorescence Protein (DsRed) fluorescent markers to select unlinked stable transpositions of <jats:italic>dSpm</jats:italic>. Using this system, we could demonstrate high frequencies of unlinked germinal transposition of <jats:italic>dSpm</jats:italic> in rice. Analysis of <jats:italic>dSpm</jats:italic> flanking sequences from 353 stable insertion lines revealed that the <jats:italic>dSpm</jats:italic> insertions appear to be widely distributed on rice chromosomes with a preference for genic regions (70%). The <jats:italic>dSpm</jats:italic> insertions appear to differ from Activator‐Dissociation (<jats:italic>Ac‐Ds</jats:italic>) elements in genomic distribution and exhibit a greater fraction of unlinked transpositions when compared with <jats:italic>Ds</jats:italic> elements. The results obtained in this study demonstrate that the maize <jats:italic>En/Spm</jats:italic> element can be used as an effective tool for functional genomics in rice and can complement efforts using other insertional mutagens. Further, the efficacy of the non‐invasive fluorescence‐based selection system is promising for its application to other crops.</jats:p>