A suite of Gateway® compatible ternary expression vectors for functional analysis in Zymoseptoria tritici

Gene overexpression is a widely used functional genomics approach in fungal biology. However, to date it has not been established in Zymoseptoria tritici which is an important pathogen of wheat (Triticum species). Here we report a suite of Gateway® recombination compatible ternary expression vectors for Agrobacterium tumefaciens mediated transformation of Z. tritici. The suite of 32 vectors is based on a combination of four resistance markers for positive selection against glufosinate ammonium, geneticin, hygromycin and sulfonylurea; three constitutive Z. tritici promoters (pZtATUB, pZtGAPDH and pZtTEF) and a nitrogen responsive promoter (pZtNIA1) for controlled expression of the open reading frames. Half of the vectors facilitate expression of proteins tagged with C-terminal EGFP. All 32 vectors allow high frequency targeting of the overexpression cassette into the Ku70 locus and complement the Ku70 gene when transformed into a Z. tritici ku70 null strain, thus circumventing additional phenotypes that can arise from random integration. This suite of ternary expression vectors will be a useful tool for functional analysis through gene overexpression in Z. tritici.