Tropaeolum Tops Tobacco - Simple and Efficient Transgene Expression in the Order Brassicales

Abstract

Transient expression systems are valuable tools in molecular biology. Agrobacterial infiltration of leaves is wellestablished in tobacco, but has led to limited success in the model plant Arabidopsis thaliana. An efficient expression system combining the advantages of Arabidopsis (well-characterised) and the simplicity of leaf infiltration is desirable. Here, I describe Agrobacterium tumefaciens-mediated transformation of Tropaeolum majus (nasturtium, order Brassicales) as a remarkably simple, cheap and highly efficient transient expression system. It provides the Arabidopsis community with a tool to study subcellular localisation, protein-protein interactions and reporter gene activities (e.g. luciferase, β-glucuronidase) in a genetic background that is closely related to their primary model organism. Unlike Arabidopsis, Tropaeolum is capable of engaging in endomycorrhizal associations and is therefore relevant also to symbiosis research. RNAi-based approaches are more likely to succeed than in the distantly-related Nicotiana transformation system. Tropaeolum majus was voted the "medicinal plant of the year 2013". Conquering this plant for genetic manipulations harbours potential for biotechnological and pharmacological applications. © 2013 Pitzschke et al.