Fig. 3: Increasing IU pathway flux to improve cell growth.

a Examining the effects of overexpressing ScCKI1 and AtPIK individually or in combination using episomal plasmids, supplemented with 5 g/L prenol. b, c AtIPK, MvIPK, and MtIPK were expressed individually and synergistically with SmDAGK with episomal plasmids in strain IUP1, supplemented with 5 g/L prenol or isoprenol. p = 0.04 between WT and IUP1-4 (isoprenol) compared with OD₆₀₀. d Impact of IU pathway introduction strategy on flux, IU pathway (vector) represents SmDAGK and AtIPK expressed based on episomal plasmids. IU pathway (chromosome) represents SmDAGK and AtIPK expressed based on chromosome integration. The isoprenol concentration was 5 g/L when added. e Differences in the expression levels of the SmDAGK gene and AtIPK gene in different strains. p = 0.0132 between IUP3 and IUP3 (isoprenol) compared with transcription level of SmDAGK. p = 0.0110 between IUP3 and IUP3 (isoprenol) compared with transcription level of AtIPK. f Schematic diagram of different IU introduction strategies. Statistical significance was evaluated by a two-tailed student’s t test (ns represents no significant difference, *p < 0.05, **p < 0.01, ***p < 0.001). Data represent mean value with SD (three independent biological replicates). g Transcriptional analysis of engineered strains. Four groups included the WT group, WT + isoprenol group, IUP3+isoprenol group, and IUP4 + isoprenol group. Source data are provided as a Source Data file.