Figure 1.

Ethylene production in tobacco following challenge with P. syringae pathovars and flagellin. A, C₂H₄ production in tobacco leaves infiltrated with strains of P. syringae pathovars as detected using LPAD. The intercellular spaces in tobacco leaves were infiltrated with bacterial suspensions (2 × 10⁶ colony-forming units mL⁻¹) with the avirulent strain Psph, (⋄), the nonpathogenic and non-HR-eliciting derivative Psph hrpL (▪), and the virulent strain Pt (▴). The two rises associated with challenges with avirulent bacteria are indicated by shading and annotation as C₂H₄-I and C₂H₄-II. An increase in ethylene production, which may be elicited by the wounding associated with the injection procedure, is arrowed. B, C₂H₄ production elicited following infiltration with 50 (♦), 25 (□), and 12.5 (△) μg mL⁻¹ Psph, flg22 with water (×) representing the negative control.