Figure 2.

The postulated pathway of DSP toxin production in relation to NRPS/PKS. Light may trigger gene transcription for hybrid enzymes of non-ribosomal peptide synthase and polykeitide synthase (hybrid NRPS/PKS). The enzymes are then translated to produce DSP toxin. Acetate reacts with glycolate to form DTX-5b, which may undergo single carbon deletion to form DTX-5a. DTX-4 may be transported from chloroplasts to vacuoles at the periphery of the cells by light-mediated transporters. In vacuoles, DTX-4 convert to the OA-diol ester, which transform into either OA or DTX 1. The dot line in the figure indicated as the postulated parts of the pathway.