Fig. 6.

HopI1 interference with salicylic acid-dependent defenses.

(A) Growth of the ΔhopI1 strain was not attenuated in SA-deficient Col (NahG). The growth defect of the ΔhopI1 strain was largely suppressed in the SA-deficient Col sid2-1 mutant. The ΔhopI1 strain grows slightly better with the hopI1-complementing clone in sid2-1 (*P<0.05): white bar, PmaES4326 with empty vector pCKTR; black bar, the ΔhopI1 strain with the empty vector; gray bar, ΔhopI1 with the hopI1 gene (JJ19). Data represent the means of 8 samples with standard errors.

(B) acd6-1 plants expressing HopI1 were larger than the acd6-1 plants alone. Four week-old plants were photographed.

(C) PR1 mRNA accumulation was lower in acd6-1 plants expressing HopI1 than in acd6-1 plants alone, as determined by quantitative real time RT-PCR. HopI1 did not change PR1 expression in Col. Values are relative to the PR1 level in acd6-1 normalized to EF1α. The mean value of 3 independent experiments, each containing triplicates of 2–4 lines/genotype is shown with standard error.

(D) The free (left panel) and total (right panel) SA level is lower in 23 day old acd6-1 plants expressing HopI1 than in acd6-1 plants alone. HopI1 did not change the SA level in Col. Error bars show standard error (n=3). This experiment was repeated with 5 week-old plants with similar results.