摘要：SummaryBergamotenes are bicyclo[3.1.1]heptane sesquiterpenes found abundantly in plants and fungi. Known bergamotene derivatives all possess (2S,6S)-bergamotene backbone. In this study, two (+)-α-trans-bergamotene derivatives (1and2) with unusual (2R,6R) configuration were isolated and elucidated from marine fungusNectriasp. HLS206.The first (+)-α-trans-bergamotene synthase NsBERS was characterized using genome mining and heterologous expression-based strategies. Based on homology search, we characterized another (+)-α-trans-bergamotene synthase LsBERS fromLachnellula suecicaand an (+)-α-bisabolol synthase BcBOS fromBotrytis cinerea. We proposed that the cyclization mechanism of (+)-α-trans-bergamotene involvedendo-anticyclization of left-handed helix farnesyl pyrophosphate by (6R)-bisabolyl cation, which was supported by molecular docking. The biosynthesis-based volatiles (3–6) produced by heterologous fungal expression systems elicited significant electroantennographic responses ofHelicoverpa armigeraandSpodoptera frugiperda, respectively, suggesting their potential in biocontrol of these pests. This work enriches diversity of sesquiterpenoids and fungal sesquiterpene synthases, providing insight into the enzymatic mechanism of formation of enantiomeric sesquiterpenes.Graphical abstractDisplay OmittedHighlights•Bergamotene derivatives with unusual (2R,6R) configurations from marine fungus•(+)-α-trans-bergamotene synthase NsBERS as a gateway to identify LsBERS and BcBOS•Theendo-anticyclization of left-handed helix FPP involving (6R)-bisabolyl cation•Volatiles elicited significant EAG responses suggesting their biocontrol potentialBiosynthesis; Mycology
