Fig 4. Impact of Dim2 on nucleotide composition and TE activity.

(A) and (B) Correspondence analyses showing differences in dinucleotide (2mer) frequencies in TEs of different Z. tritici isolates (A) and other members of the Zymoseptoria species complex (B). TA and CA/TG dinucleotide frequencies have the highest impact on the observed differences between isolates and species, indicated by their relative positions on the dimension 1 versus dimension 2 plot. Isolates (even from different species) containing a functional dim2 (Zt10, Zt289, Zt11, Zt469, TN09, Zb87, Za17, Zpa63) and recently mutated dim2 (ISY92 and YEQ92) have higher TA content and cluster together, while isolates without functional dim2 have higher CA/TG frequencies in TE sequences. (C) Comparison of TE and GC content between different Z. tritici isolates and Zymoseptoria species with and without functional dim2. D) Number of expressed TEs during the time course of wheat infection is significantly higher in Z. tritici isolate Zt09 (non-functional dim2) compared to Zt10 (functional dim2) (Fisher’s Exact Test for Count Data, p-value < 2.2 x 10⁻¹⁶).