Towards a genetic model organism: an efficient method for stable genetic transformation of Eschscholzia californica (Ranunculales)

Abstract

California poppy (Eschscholzia californica) is a member of the Ranunculales, the sister order to all other eudicots and as such in a phylogenetically highly informative position. Ranunculales are known for their diverse floral morphologies and biosynthesis of many pharmaceutically relevant alkaloids. E. californica it is widely used as model system to study the conservation of flower developmental control genes. However, within the Ranunculales, options for stable genetic manipulations are rare and genetic model systems are thus difficult to establish. Here, we present a method for the efficient and stable genetic transformation via Agrobacterium tumefaciens-mediated transformation, somatic embryo induction, and regeneration of E. californica. Further, we provide a rapid method for protoplast isolation and transformation. This allows the study of gene functions in a single-cell and full plant context to enable gene function analysis and modification of alkaloid biosynthesis pathways by e.g., genome editing techniques providing important resources for the genetic model organism E. californica.