Identification of the pleiotropic function of TOUSLED kinase in tomato (Solanum lycopersicum L.) using a Cucumber mosaic virus-based vector

Abstract

TOUSLED (TSL) is a nuclear serine/threonine kinase highly conserved in plants and animals, including humans. In Arabidopsis thaliana, TSL participates in leaf and flower morphogenesis, cell-cycle regulation, and maintenance of transcriptional gene silencing. To identify the functions of TSL in tomato, we conducted TSL gene silencing using a reassortant Gn-CMV vector. Two parts of the tomato TSL gene, the 3' proximal and middle regions of the TSL ORF (termed tsl-4 and tsl-9), were amplified and cloned into the Y-R2A1 vector. Tomato plants inoculated with the Gn-tsl4 and Gn-tsl9 vectors showed pleiotropic effects, such as changes in leaf color, formation of thick stems, reduction of genome size, and extreme bud outgrowth. The mechanisms of bud outgrowth have been well studied in various plant species, but this is the first report of a function for TSL in bud outgrowth of tomato. In addition, our results showed that the reassortant Gn-CMV vector can be successfully applied for virus-induced gene silencing to study functional genomics in tomato.