Impact of Massive mPing Transposition on Gene Expression Under Cold Stress

Transposable elements (TEs) are ubiquitous in the eukaryotic genomes, but their roles in the host genomes are largely unknown. MITEs are the predominant TEs associated with the non-coding regions of the genes of flowering plants. A group of Tourist-like MITE, named mPing, was found to transpose actively and reached high copy number in some rice cultivar strains. Previous studies have suggested that the sudden burst of mPing transposition in these strains has modest impact on host through targeting mechanisms to minimize impact on host gene expression. We tested this hypothesis with new data generated from next-generation sequencing technologies. We resequenced the high copy mPing strain HEG4 and its progenitor EG4 to identify mPing insertions and to compared to the genome of Nipponbare (NB), which has moderate copy numbers of mPing. We also explored the changes and differences of expression profiles in leaf transcriptiome upon cold stress of these strains by RNA-seq analysis. The impact of mPing transposition on host gene expression will be evaluated based on our new data.