Transposon Ds-Mediated Insertional Mutagenesis in Rice (Oryza sativa)

Abstract

Rice (Oryza sativa) is the most important consumed staple food for a large and diverse population worldwide. Since databases of genomic sequences became available, functional genomics and genetic manipulations have been widely practiced in rice research communities. Insertional mutants are the most common genetic materials utilized to analyze gene function. To mutagenize rice genomes, we exploited the transpositional activity of an Activator/Dissociation (Ac/Ds) system in rice. To mobilize Ds in rice genomes, a maize Ac cDNA was expressed under the CaMV35S promoter, and a gene trap Ds was utilized to detect expression of host genes via the reporter gene GUS. Conventional transposon-mediated gene-tagging systems rely on genetic crossing and selection markers. Furthermore, the activities of transposases have to be monitored. By taking advantage of the fact that Ds becomes highly active during tissue culture, a plant regeneration system employing tissue culture was employed to generate a large Ds transposant population in rice. This system overcomes the requirement for markers and the monitoring of Ac activity. In the regenerated populations, more than 70% of the plant lines contained independent Ds insertions and 12% expressed GUS at seedling stages. This protocol describes the method for producing a Ds-mediated insertional population via tissue culture regeneration systems. © 2016 by John Wiley & Sons, Inc.