Wheat’s MAPK signaling helps SGT1 enter the nucleus and is targeted by a stripe rust pathogen protein

A wheat MAPK cascade composed of TaMKK2 and TaMAPK6 is essential for resistance against the wheat pathogen Puccinia striiformis f. sp. tritici (Pst).

• The TaMAPK6 protein phosphorylates the immune regulator TaSGT1, enhancing its entry into the nucleus.
• Phosphorylation of TaSGT1 by TaMAPK6 is crucial for activating plant immunity against Pst.
• The pathogen Pst secretes a protein, HASP215, that disrupts the interaction between TaMKK2 and TaMAPK6.
• This disruption leads to decreased phosphorylation and activation of TaMAPK6, impairing its ability to activate TaSGT1.
• As a result, the nuclear translocation of TaSGT1 is reduced, which suppresses plant immunity.

Simplified