Development of transgenic corn planthopper Peregrinus maidis that express the tetracycline transactivator

The corn planthopper, Peregrinus maidis, is a vector of several maize viruses and is consequently a significant agricultural pest in many tropical and subtropical regions. As P. maidis has developed resistance to insecticides, the aim of this study was to develop transgenic P. maidis strains that could be used for future genetic biocontrol programs. To facilitate the identification of transgenic P. maidis, we isolated and characterized the promoters for the P. maidis ubiquitin-like and profilin genes. Transient expression assays with P. maidis embryos showed that both promoters were active. Transgenic lines were established using piggyBac vectors and fluorescent protein marker genes. The lines carried an auto-regulated tetracycline transactivator (tTA) gene, which has been widely used to establish conditional lethal strains in other insect species. The transgenic lines showed low levels of tTA expression but were viable on diet with or without doxycycline, which inhibits the binding of tTA to DNA. We discuss possible modifications to the tTA overexpression system that could lead to the successful development of conditional lethal strains. To our knowledge, this is the first report of a transgenic Hemiptera. The approach we have taken could potentially be applied to other Hemiptera and, for P. maidis, the technology will facilitate future functional genomics studies.