Figure 3.

Genetic Tests to Discriminate between the Guard and Decoy Models.

Plants lacking both the R protein and the presumed operative target(s) should be challenged with pathogens in the absence or presence of the guardee/decoy. A differential pathogen growth supports the Guard Model, whereas an unaffected pathogen growth supports the Decoy Model. The test of choice depends on the nature of the effector.

(A) Effectors that promote positive effects on pathogen growth by manipulating their target should be present during the test to reveal target contributions.

(B) Effectors that prevent negative effects on pathogen growth should be omitted to avoid them from suppressing a possible phenotype.