"Antagonistic control of pre-activation disease resistance protein stability in the plant immune system."

Science DOI: 10.1126/science.1109977

Holt III, BF, Y Belkhadir and JL Dangl

Summary "Pathogen recognition by the plant immune system is governed by structurally related, polymorphic products of disease resistance (R) genes. RAR1 and/or SGT1b mediate the function of many R proteins. RAR1 controls pre-activation R protein accumulation by an unknown mechanism. We demonstrate that Arabidopsis SGT1b has two distinct, genetically separable functions in the plant immune system: SGT1b antagonizes RAR1 to negatively regulate R protein accumulation before infection, and SGT1b has a RAR1- independent function that regulates programmed cell death during infection. The balanced activities of RAR1 and SGT1, in concert with cytosolic HSP90, modulate preactivation R protein accumulation and signaling competence."