Monoterpenes have a wide applications ranging from food and cosmetic industries to advanced biofuels.Compared with sesquiterpenes,microbial production of monoterpene is still lagging in Saccharomyces cerevisiae due to the shortage in precursor geranyl diphosphate (GPP) and its toxicity to cell.In this study,monoterpene geraniol,a valuable acyclic monoterpene alcohol,was employed as an indicator in response to the availability of engineered pathway.First,three geraniol synthases were evaluated three geraniol synthases in S.cerevisiae,and the geraniol synthase without a plastid-targeting peptide from Valeriana officinalis (t VoGES),had a highest enzyme activity for geraniol production.To improve precursor GPP synthesis,three specific GPP synthase genes derived from different plants and two endogenous farnesyl diphosphate (FPP) synthase genes variants ERG20K197G and ERG20F96W-N127W with higher GPP synthase activity than FPP synthase,were compared,and ERG20F96W-N127W significantly improved geraniol production by co-overexpressing two rate-limiting genes,IDIland tHMGl,and a global transcription factor UPC2-1.In addition,we designed Erg20p (F96W-N 127W)-t VoGES fusion protein to increase the flux from GPP to geraniol.Furthermore,as a key regulated branch point,we explored dynamic control of ERG20 expression to redistribute the precursor GPP flux and achieved a 3.4-fold increase in geraniol production after optimizing carbon source feeding.Given that geraniol could be endogenous metabolized by intracellular non-specificity reaction,we deleted OYE2 (encoding an NADPH oxidoreductase) or ATF1 (encoding an alcohol acetyltransferase) both involving endogenous conversion of geraniol to other terpenoids,and improved geraniol production by 1.7-fold or 1.6-fold in batch fermentation,respectively.Finally,the combination of dynamic control of ERG20 expression and OYE2 deletion in LEU2 prototrophic strain increased geraniol production up to 1.69 g/L with pure ethanol feeding in fed-batch fermentation,which is the highest reported production in engineered yeast.Our study provides a convenient yeast host for developing the production of more complex geraniol-derived monoterpene indole alkaloids (MIAs),many of which have medicinal properties.