Decreased folate synthesis explained the lifespan increase caused by the aroD mutant. A) Schematic of the shikimic acid and folate synthesis pathways. Solid arrows represent single enzymatic steps. Dashed arrows represent multiple steps. PEP, phosphoenolpyruvate; SHK, shikimic acid; PABA, para-aminobenzoic acid. B) Shikimic acid and PABA reverse the lifespan increase caused by the aroD mutation. glp-4(bn2) animals were raised on the aroD mutant until L4 (15°C) and then transferred to the aroD mutant (n = 116), wild type control (n = 116), aroD + SHK (n = 86), aroD + PABA (n = 76), (25°C). All supplements at 40 μg/ml. aroD + PABA vs aroD, P = < 0.0001; aroD + SHK vs aroD, P = < 0.0001. C) Levels of formylTHFGlu3 as detected by LC-MS are decreased in the aroD mutant compared to the wild type HT115(DE3). Data from two biological replicates.