Table 1. Overview on major features of Tropaeolum majus agroinfiltration as transient expression system.

Taxonomic aspects	T . majus belongs in the order Brassicales, as does Arabidopsis . RNAi-based gene silencing with Arabidopsis -derived DNA constructs is more likely to succeed in Tropaeolum than in Nicotiana.
Experimental aspects	Plant growth
	Modest space requirements
	Multiple plants grown in the same pot can be bound to the site (long flexible stems).
	Climate-controlled growth cabinet not required
	Transformation procedure
	simple and inexpensive
	Expanded leaves are equally suitable, no leaf-to-leaf variation observed.
	Infiltration requires some empirically acquired know-how. The infiltration liquid moves slowly, but gradually (30 sec/8 qcm).
	Transgene expression and kinetics
	Transformation efficiency is reproducibly high. > 80% of cells in the infiltrated area express the transgene (here tested for YFP, GUS, Luciferase).
	Expression detectable 4 days-post-infiltration (dpi), observed >10 dpi, (transient, kinetics comparable to Nicotiana ).
	Multiple gene transfer possible, e.g. for effector/reporter gene studies; interaction studies (here tested via BiFC assay).
	Limitations
	“Lotus effect”: Treatment with liquid effector substances (e.g. elicitors in stress research) may have to be applied by infiltration.
Perspectives for basic and applied research	Relevant tool for basic research, e.g.
	Endomycorrhizal interactions
	Biosynthesis and metabolism of glucosinolates and oleates
	Pharma industry and biotechnology
	May facilitate isolation of key components in biosynthesis of health-promoting substances (for transfer into other species; for in vitro synthesis etc.)
	Transgenic T . majus cell cultures may be established for large-scale production of desired substances and phyto-pharmaceuticals.