Virus-Induced Gene Silencing of the Alkaloid-Producing Basal Eudicot Model Plant Eschscholzia californica (California Poppy)

Eschscholzia californica (California poppy), a member of the basal eudicot family of the Papaveraceae, is an important species to study alkaloid biosynthesis and the effect of alkaloids on plant metabolism. More recently, it has also been developed as a model system to study the evolution of plant morphogenesis. While progress has been made towards establishing methods for generating genetically modified cell culture lines, transcriptome data and gene expression analysis, the stable transformation and subsequent regeneration of transgenic plants has proven extremely time consuming and difficult. Here, we describe in detail a method to transiently down regulate expression of a target gene by virus-induced gene silencing (VIGS) and the subsequent analysis of the VIGS treated plants. VIGS in E . californica allows for the study of gene function within 2 to 3 weeks after inoculation, and the method proves very efficient, enabling the rapid analysis of gene functions.