<p>A, Stomatal aperture in <i>V. faba</i> epidermal peels incubated with different treatments. Data are means of 120 stomatal aperture measurements from three replicates ±SEM; B, ROS accumulation in intact guard cells detected by H<sub>2</sub>DCF-DA fluorescence. The microscopic images represent fluorescent and DIC images of peels treated with mock (upper left and right), fluorescent image of peels treated with DH5α at 10<sup>8</sup> CFU/ml (lower left), and fluorescent image of peels treated with 1 mM LPS (lower right). Bars = 50 µm; C, Quantitation of generated ROS in <i>Vicia faba</i> guard cells as shown in B. Asterisks denote significant differences as analyzed by two-tailed <i>t</i>-test (***, <i>P</i><0.001; ns, no statistical difference).</p
