20955813
not annotated - annotated - LINNAEUS only
Comparative sequence analysis of wheat and barley powdery mildew fungi reveals gene colinearity, dates divergence and indicates host-pathogen co-evolution.
The two fungal pathogens Blumeria graminis f. sp. triticiBlumeria graminis f. sp. tritici (B.g. tritici) and hordei (B.g. hordei) cause powdery mildew specifically in wheat or barley. They have the same life cycle, but their growth is restricted to the respective host. Here, we compared the sequences of two loci in both cereal mildews to determine their divergence time and their relationship with the evolution of their hosts. We sequenced a total of 273.3kb derived from B.g. tritici BAC sequences and compared them with the orthologous regions in the B.g. hordei genome. Protein-coding genes were colinear and well conserved. In contrast, the intergenic regions showed very low conservation mostly due to different integration patterns of transposable elements. To estimate the divergence time of B.g. tritici and B.g. hordei, we used conserved intergenic sequences including orthologous transposable elements. This revealed that B.g. tritici and B.g. hordei have diverged about 10 million years ago (MYA), two million years after wheat and barley (12 MYA). These data suggest that B.g. tritici and B.g. hordei have co-evolved with their hosts during most of their evolutionary history after host divergence, possibly after a short phase of host expansion when the same pathogen could still grow on the two diverged hosts.
Ann file
T1 Species 33 38 wheat
N1 Reference T1 Taxonomy:4565
T2 Species 43 49 barley
N2 Reference T2 Taxonomy:4513
T3 Species 183 215 Blumeria graminis f. sp. tritici
T4 Species 217 229 B.g. tritici
T5 Species 183 207;235 241 Blumeria graminis f. sp. hordei
T6 Species 243 254 B.g. hordei
T7 Species 293 298 wheat
N7 Reference T7 Taxonomy:4565
T8 Species 302 308 barley
N8 Reference T8 Taxonomy:4513
T9 Species 601 613 B.g. tritici
T10 Species 682 693 B.g. hordei
T11 Species 928 940 B.g. tritici
T12 Species 945 956 B.g. hordei
T13 Species 1061 1073 B.g. tritici
T14 Species 1078 1089 B.g. hordei
T15 Species 1162 1167 wheat
N15 Reference T15 Taxonomy:4565
T16 Species 1172 1178 barley
N16 Reference T16 Taxonomy:4513
T17 Species 1213 1225 B.g. tritici
T18 Species 1230 1241 B.g. hordei
N19 Reference T3 Taxonomy:62690 Blumeria graminis f. sp. tritici
N20 Reference T4 Taxonomy:62690 Blumeria graminis f. sp. tritici
N21 Reference T5 Taxonomy:62688 Blumeria graminis f. sp. hordei
N22 Reference T6 Taxonomy:62688 Blumeria graminis f. sp. hordei
N23 Reference T9 Taxonomy:62690 Blumeria graminis f. sp. tritici
N24 Reference T11 Taxonomy:62690 Blumeria graminis f. sp. tritici
N25 Reference T13 Taxonomy:62690 Blumeria graminis f. sp. tritici
N26 Reference T17 Taxonomy:62690 Blumeria graminis f. sp. tritici
N27 Reference T10 Taxonomy:62688 Blumeria graminis f. sp. hordei
N28 Reference T12 Taxonomy:62688 Blumeria graminis f. sp. hordei
N29 Reference T14 Taxonomy:62688 Blumeria graminis f. sp. hordei
N30 Reference T18 Taxonomy:62688 Blumeria graminis f. sp. hordei