Fig 5. RHA1B suppresses ETI signaling by promoting the E3-dependent degradation of the NB-LRR receptor.

(A) The E3 ubiquitin ligase activity of RHA1B is required for HR cell death suppression. N. benthamiana leaves were agro-infiltrated with combination of either ^ΔSPRHA1B, empty vector, or ^ΔSPRHA1B^C135S with NB-LRR receptor and its cognate avirulence effector (Gpa2/RBP1 or Bs4/AvrBs4) or with the auto-active NB-LRR mutant (Prf^D1416V, Rx1^D460V or Rpi-blb1^D475V) at appropriate inoculum. Photographs were taken 5 days after agro-injection. (B) RHA1B promotes degradation of NB-LRR immune receptors. The accumulation of NB-LRR or PRR proteins in the presence of ^ΔSPRHA1B, empty vector, or ^ΔSPRHA1B^C135S was determined by WB using appropriate antibodies. (A, B) Experiments were repeated at least three times with similar results.