Dehydratase; part of the Pks1 gene cluster that mediates the biosynthesis of an anthraquinone derivative pigment that contributes to conidial pigmentation that provides protection from UV radiation, heat and cold stress (PubMed:28447400). The polyketide synthase Pks1 produces 1-acetyl-2,4,6,8-tetrahydroxy-9,10-anthraquinone though condensation of acetyl-CoA with malonyl-CoA (Probable). The dehydratase EthD and the laccase Mlac1 further convert the anthraquinone derivative into the final conidial pigment (Probable). Pigment biosynthesis. Highly expressed during conidiation (PubMed:28447400). A conserved conidiation regulatory pathway containing BrlA, AbaA and WetA regulates expression. During conidiation BlrA up-regulates AbaA, which in turn controls WetA. Moreover, the Hog1 MAPK regulates fungal conidiation by controlling the conidiation regulatory pathway, and that all three pigmentation genes Pks1, EthD and Mlac1 exercise feedback regulation of conidiation (PubMed:28447400). Leads to the production of dark red conidia (PubMed:28447400). Does not affect virulence (PubMed:28447400). Belongs to the tpcK family.