Transcriptional regulator; part of the gene cluster that mediates the biosynthesis of pyriculol and pyriculariol, two heptaketides that induce lesion formation upon application on rice leaves but are dispensable for pathogenicity (PubMed:27902426). With TRF2, negatively regulates the expression of the gene cluster and the subsequent pyriculol and pyriculariol production (PubMed:27902426). Leads to increased expression of the pyriculol/pyriculariol biosynthesis cluster highly reducing polyketide synthase PKS19.