Exposure to stressful environmental conditions can induce severe metabolic variations in basil (Ocimum
basilicum) aroma. The aromatic profiles of Dark Opal and Red Rubim varieties (in vivo plants, in vitro
shoots, callus, and suspension cultures) were investigated for the first time. The established calli represented
the most interesting miniaturised aromatic plant systems, as they were able to emit many typical
basil volatiles with very low amounts of phenylpropanoids (1–2%). The hydrocarbon monoterpenes and
oxygenated volatiles emitted from calli of both varieties were greatly and conversely affected by UV-C
and UV-B, in comparison with the non-irradiated samples. As calli of both varieties still maintained very
low levels of phenylpropanoids even after UV elicitation, they might be regarded not only as efficient
in vitro plant models to study volatile compounds under UV stress conditions, but also as safe aromatic
biomass in comparison with in vivo basil plants.