A real-time visualized TRSV-based gene silencing method using trichome as a selected marker in cucumber

Cucumber (Cucumis sativus. L) is economically valuable vegetable crop worldwide. Although cucumber genomic sequence has been completed, the functions of most genes have not yet been characterized. Virus-induced gene silencing (VIGS) is an efficient system for investigating gene function in plants, however, detection of VIGS efficiency by PCR is a time-consuming method. In this study, a vacuum-agroinfiltrated Tobacco ringspot virus (TRSV)-based gene silencing method was developed in cucumber, and CsGLABROUS3 (CsGL3), which functions in initiation of trichome, was cloned into pTRSV2 vector to develop a TRSV-CsGL3 system. Gene silenced cucumbers were visible using trichome as a selected marker, and their glabrous phenotype exhibited throughout the life cycle in TRSV-CsGL3 system. Thereafter, a flower morphogenesis gene (UNUSUAL FLORAL ORGANS, CsUFO) was selected to silence by the TRSV-CsGL3 system, and CsUFO silenced cucumbers produced the flower defect phenotype as expected. In summary, TRSV-CsGL3 is a real-time visualized VIGS system using trichome as a selected marker, which simplify the VIGS identification procedure, and it can be used to investigate gene function throughout the life cycle in cucumber.