Figure 3. Headspace analysis of volatiles emitted from agro-infiltrated Nicotiana benthamiana leaves.

A, GC-MS chromatograms are shown for the volatiles emitted from N.benthamiana leaves infiltrated with the indicated genes. Line a is a negative control, line b and c display the different amount of compound 1 (germacrene A) produced by N. benthamiana leaves infiltrated with TpGAS with different targeting signals: mTpGAS, mitochondrial targeting; cTpGAS, cytosolic targeting. Line d shows that compound 1 which is produced upon mTpGAS agro-infiltration disappears upon agro-infiltration with CiGAO. Agro-infiltration with CiGAO alone does not induce any volatile formation (Line e). B, the mass fragmentation patterns of compound 1 (a) and a β-elemene from the Wiley library (b). C, cope rearrangement of germacrene A to β-elemene by heat.