Methyl jasmonate induces ganoderic acid biosynthesis in the basidiomycetous fungus Ganoderma lucidum

This is the first time study to assess the novel use of methyl jasmonate (MeJA) to elicit ganoderic acid (GA) biosynthesis in Ganoderma lucidum and the resulting experiments demonstrated that MeJA was indeed a potent inducer of GA biosynthesis. To maximize GA synthesis, a statistical methodology called uniform design (UD) was used to optimize inducement conditions, which were determined to be 254 microM MeJA solubilized in Tween-20 that was added to the culture on day 6. The resulting GA yield was 4.52 mg/100mg dry weight (DW), which was 45.3% higher than the untreated control sample. To characterize the effect of MeJA on GA biosynthesis, quantitative real-time PCR was used to measure transcription levels of several genes in the synthesis pathway including hydroxy-3-methylglutaryl-Coenzyme A synthase (hmgs), hydroxy-3-methylglutaryl-Coenzyme A reductase (hmgr), mevalonate-5-pyrophosphate decarboxylase (mvd), farnesyl pyrophosphate synthase (fps), squalene synthase (sqs) and oxidosqualene cyclase (osc). Quantification of transcription levels determined that MeJA significantly induced expression of these genes.