A wheat tandem kinase activates an NLR to trigger immunity
Renjie Chen, Jian Chen, Oliver R. Powell, Megan A. Outram, Taj Arndell, Karthick Gajendiran, Yan L. Wang, Jibril Lubega, Yang Xu, Michael Ayliffe, Cheryl Blundell, Melania Figueroa, Jana Sperschneider, Thomas Vanhercke, K. Kanyuka, Dingzhong Tang, Guitao Zhong, Catherine Gardener, Guotai Yu, Spyridon Gourdoupis, Łukasz Jaremko, Oadi Matny, Brian J. Steffenson, Willem H. P. Boshoff, W. Meyer, Stefan T. Arold, Peter N. Dodds, Brande B. H. Wulff
Abstract
The role of nucleotide-binding leucine-rich repeat (NLR) receptors in plant immunity is well studied, but the function of a class of tandem kinases (TKs) that confer disease resistance in wheat and barley remains unclear. In this study, we show that the SR62 locus is a digenic module encoding the Sr62 TK TK and an NLR (Sr62 NLR ), and we identify the corresponding AvrSr62 effector. AvrSr62 binds to the N-terminal kinase 1 of Sr62 TK , triggering displacement of kinase 2, which activates Sr62 NLR . Modeling and mutation analysis indicated that this is mediated by overlapping binding sites (i) on kinase 1 for binding AvrSr62 and kinase 2 and (ii) on kinase 2 for binding kinase 1 and Sr62 NLR . Understanding this two-component resistance complex may help engineering and breeding plants for durable resistance.