The role of the dspE gene in pathogenicity and HR elicitation. (A) Immature pear fruit 4 days after inoculation with (left to right) strains Ea321, Ea321dspEΔ1554, or Ea321dspEΔ1554 harboring the 5′ half of dspE on pCPP1237. (B) Norchief soybean leaf 24 hr after infiltration with 5 × 108 cfu/ml suspensions of (1) Ea321, (2) Ea321dspEΔ1554, (3) Ea321hrpN∷Tn5 (ref. 4), and (4) Ea321hrpL∷Tn5 (ref. 1). (C) Tobacco leaf 48 hr after infiltration with parallel dilution series of suspensions of strains Ea321 (Left) and Ea321dspEΔ1554 (Right). The concentrations infiltrated (top to bottom) are 1 × 1010, 1 × 109, 5 × 108, 1 × 108, and 5 × 107 cfu/ml. (D) As for C, except the more virulent strain, Ea273, and corresponding mutant Ea273dspEΔ1554 were used, and concentrations ranged from 5 × 109 to 5 × 105 cfu/ml in log increments.