The Brassica napus wall‐associated kinase‐like (WAKL) gene Rlm9 provides race‐specific blackleg resistance. (7th October 2020)

• Record Type: Journal Article
• Authors: Larkan, Nicholas J.; Ma, Lisong; Haddadi, Parham; Buchwaldt, Miles; Parkin, Isobel A.P.; Djavaheri, Mohammad; Borhan, M. Hossein
• Is Part Of: Plant journal. Volume 104:Number 4(2020)
• Page Start: 892
• Page End: 900
• Publication Date: 2020-10-07
• Subjects: Leptosphaeria maculans -- blackleg -- Brassica napus -- Rlm9 -- AvrLm5‐9 -- disease resistance -- wall‐associated kinase‐like; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14966
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: In plants, race‐specific defence against microbial pathogens is facilitated by resistance ( R ) genes which correspond to specific pathogen avirulence 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 and while not conclusive, our work did not indicate 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. Significance Statement: Rlm9 encodes a wall‐associated kinase‐like (WAKL) race‐specific resistance protein, is a member of an emerging class of race‐specific plant receptor‐like kinase resistance genes and is the first of its kind to be cloned from a dicot species.