Figure 1.
Putative STL biosynthetic pathway in chicory. The biosynthetic pathway of chicory STLs has been partly elucidated. Enzymes catalyzing the conversion of FPP to kauniolide have been previously characterized. The chicory lactucin synthase CiLCS converts 8-deoxylactucin to lactucin (this work). Dashed arrows indicate uncharacterized enzymatic conversions. FPP—farnesyl pyrophosphate, CiGAS—germacrene A synthase, CiGAO—germacrene A oxidase, CiCOS—costunolide synthase, CiKLS—kauniolide synthase, and CiLCS—lactucin synthase.