Involvement of a Polyketide Synthetase CIPKS18 in the Regulation of Vegetative Growth, Melanin and Toxin Synthesis, and Virulence in Curvularia lunata

The clpksl8 gene was first cloned and identified in Curvularia lunata. It contains 6571 base pairs (bp) and an 6276 bp open reading frame encoding 2091 amino acids. The CIPKS18 deletion mutant displayed an albino phenotype, and almost lost the ability to product 5-(hydroxymethyl) furan-2-carboxylate (M5HF2C) toxin, implying that clpksl8 gene in C. lunata is not only involved in 1,8-dihydroxynaphthalene melanin synthesis, but also relatively associated with M5HF2C toxin biosynthesis of the pathogen. The pathogenicity assays revealed that Delta CIPKS18 was impaired in colonizing the maize leaves, which corresponds to the finding that CIPKS18 controls the production of melanin and M5HF2C in C. lunata. Results indicate that CIPKS18 plays a vital role in regulating pathogenicity of in C. lunata.