RT Journal Article
SR Electronic
T1 A fungal avirulence factor encoded in a highly plastic genomic region triggers partial resistance to septoria tritici blotch
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 264226
DO 10.1101/264226
A1 Lukas Meile
A1 Daniel Croll
A1 Patrick C. Brunner
A1 Clémence Plissonneau
A1 Fanny E. Hartmann
A1 Bruce A. McDonald
A1 Andrea Sánchez-Vallet
YR 2018
UL http://biorxiv.org/content/early/2018/02/23/264226.abstract
AB Cultivar-strain specificity in the wheat-Zymoseptoria tritici pathosystem determines the infection outcome and is controlled by resistance genes on the host side, of which many have been identified. However, on the pathogen side, the molecular determinants of specificity are largely unknown.We used genetic mapping, targeted gene disruption and allele swapping to characterize the recognition of the new avirulence factor Avr3D1. We then combined population genetic and comparative genomic analyses to estimate the evolutionary trajectory of Avr3D1.Avr3D1 is specifically recognized by cultivars harboring the resistance gene Stb7 and triggers a strong defence response without preventing pathogen infection and reproduction. Avr3D1 resides in a cluster of putative effector genes located in a region populated by independent transposable element insertions. The gene is present in all 132 investigated strains and is highly polymorphic, with a total of 30 different protein variants. We demonstrated that certain amino acid mutations in Avr3D1 led to evasion of recognition.These results demonstrate that quantitative resistance and gene-for-gene interactions are not mutually exclusive per se. Location of avirulence genes in highly plastic genomic regions likely facilitates accelerated evolution that enables escape from recognition by resistance proteins.