Figure 2. DH5α-induced stomatal closure involves ROS accumulation in guard cells.

A, Stomatal aperture in V. faba 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 H₂DCF-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 10⁸ 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 Vicia faba guard cells as shown in B. Asterisks denote significant differences as analyzed by two-tailed t-test (***, P<0.001; ns, no statistical difference).