摘要Terpenes are the largest and most diverse class of plant specialized metabolites.Ses-terterpenes(C25),which are derived from the plastid methylerythritol phosphate pathway,were recently characterized in plants.In Arabi-dopsis thaliana,four genes encoding ger-anylfarnesyl diphosphate synthase(GFPPS)(AtGFPPS1 to 4)are responsible for the pro-duction of GFPP,which is the common pre-cursor for sesterterpene biosynthesis.However,the interplay between sesterterpenes and other known terpenes remain elusive.Here,we first provide genetic evidence to demonstrate that GFPPSs are responsible for sesterterpene pro-duction in Arabidopsis.Blockage of the sesterterpene pathway at the GFPPS step in-creased the production of geranylgeranyl di-phosphate(GGPP)-derived terpenes.Interest-ingly,co-expression of sesterTPSs in GFPPS-OE(overexpression)plants rescued the pheno-typic changes of GFPPS-OE plants by restoring the endogenous GGPP.We further demon-strated that,in addition to precursor(DMAPP/IPP)competition by GFPPS and GGPP synthase(GGPPS)in plastids,GFPPS directly decreased the activity of GGPPS through protein-protein interaction,ultimately leading to GGPP defi-ciency in planta.Our study provides a new regulatory mechanism of the plastidial terpe-noid network in plant cells.