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bioRxiv · 10.1101/815845

The Brassica napus Wall-Associated Kinase-Like (WAKL) gene Rlm9 provides race-specific blackleg resistance

Larkan, N. J.·Ma, L.·Haddadi, P.·Buchwaldt, M.·Parkin, I. A. P.·Djavaheri, M.·Borhan, M. H.
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Abstract

In plants, race-specific defense against microbial pathogens is facilitated by resistance (R) genes which correspond to specific pathogen avirulence (Avr) genes. This study reports the cloning of a blackleg R gene from Brassica napus (canola); Rlm9, which encodes a wall-associated kinase-like (WAKL) protein, a newly-discovered class of race-specific plant RLK resistance genes. Rlm9 provides race-specific resistance against isolates of Leptosphaeria maculans carrying the corresponding avirulence gene AvrLm5-9, representing only the second WAKL-type R gene described to date. The Rlm9 protein is predicted to be cell membrane-bound yet appears to have no direct interaction with AvrLm5-9. Rlm9 forms part of a distinct evolutionary family of RLK proteins in B. napus, and while little is yet known about WAKL function, the Brassica-Leptosphaeria pathosystem may prove to be a model system by which the mechanism of fungal avirulence protein recognition by WAKL-type R genes can be determined.

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Larkan, N. J., Ma, L., Haddadi, P., Buchwaldt, M., Parkin, I. A. P., Djavaheri, M., Borhan, M. H.. 2019-10-24. The Brassica napus Wall-Associated Kinase-Like (WAKL) gene Rlm9 provides race-specific blackleg resistance. https://doi.org/10.1101/815845

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