(3E,5E,7S)-5,7-dimethyl-2-oxonona-3,5-dienyl-[ACP] + 4 malonyl-CoA + AH2 + S-adenosyl-L-methionine + 3 H(+) = 6-[(3E,5E,7S)-5,7-dimethyl-2-oxonona-3,5-dienyl]-2,4-dihydroxy-3-methylbenzaldehyde + holo-[ACP] + A + S-adenosyl-L-homocysteine + 4 CO2 + 4 CoA + H2O — reaction