Figure 4.

Mo17 ZmTps21 encodes a functional β-selinene synthase. A, Mo17 ZmTps21 was heterologously expressed in E. coli, and the resulting protein extract was incubated with (E,E)-FPP. Mo17 ZmTps21 products were collected using solid-phase microextraction (SPME) and analyzed by GC-MS, revealing β-selinene (2) as the dominant product, with lower yet detectable levels of β-elemene (germacrene A rearrangement product); (1) and α-selinene (3). B, Celery (Apium graveolens) fruit essential oil was used as a natural product standard for β-selinene:α-selinene (9:1). TIC, Total ion chromatograms.