Wheat MAPK cascade mediates SGT1 nuclear entry targeted by a stripe rust effector.

Mitogen-activated protein kinase (MAPK) cascades play a fundamental role in plant immunity by transducing external signals inside plant cells. Here, we defined a wheat MAPK cascade, composed of the mitogen-activated protein kinase kinase (MAPKK) TaMKK2 and its downstream MAPK TaMAPK6, which phosphorylates the core immune regulator TaSGT1 (suppressor of G2 allele of Skp1), resulting in enhanced nuclear entry of TaSGT1, thereby conferring resistance against the devastating wheat pathogen Puccinia striiformis f. sp.