Figure 1.

P. infestans AVR2 Specifically Associates with BSL1.

(A) Immunoblots showing AVR2 specifically coimmunoprecipitates with tomato BSL1 (Sl-BSL1) in planta. FLAG:AVR2 was transiently expressed alone, with the empty vector pK7WGF2 or with GFP-tagged putative target proteins in N. benthamiana. Immunoprecipitates (IP) obtained with anti-FLAG or anti-GFP antiserum and total protein extracts were immunoblotted with appropriate antisera. The expected sizes of the GFP fusion proteins are indicated by red dots in the crude extracts and GFP co-IP probed with anti-GFP antibody. PS, Ponceau stain; Rubisco, ribulose-1,5-bisphosphate carboxylase/oxygenase.

(B) Y2H analysis illustrating that the two allelic variants of AVR2, P. infestans AVR2^K31 and AVR2^N31, and the C-terminal effector domain of AVR2 (amino acids 66 to 116) interact with potato BSL1 (St-BSL1) in vivo. Both LacZ (blue) and His3 (providing growth on medium lacking His [-his]) reporter genes were activated. Empty vector (pDEST32) was used as a negative control. The RXLR effector PITG_08949, which is closely related to AVR2 across the N-terminal translocation domain but which differs across the C-terminal effector domain due to a likely recombination event (Gilroy et al., 2011), did not interact with St-BSL1 using Y2H analysis.