Fig. 3.

Effect of NO inhibitors on induction of NO by 2R,3R-butanediol (2,3-B). (A) DAF2-DA fluorescence in guard cells induced by 100 μM 2R,3R-butanediol (2,3-B) was inhibited by the NO scavenger (PTIO) and an inhibitor of NO synthase (L-NNA). Fluorescence of leaf peel epidermal fragments are shown after 2 h incubation with DAF2-DA in MES buffer following treatments with MES buffer as a control or 100 μM 2R,3R-butanediol (2,3-B) in the presence or absence of L-NNA and PTIO. Fluorescence imaging due to the NO reaction with DAF2-DA was observed by confocal microscopy with excitation at 488 nm and emission at 515 nm. (B) Intensity of fluorescence is provided as mean pixel intensities and standard deviations based on observations of 50–100 hundred guard cells per treatment of three independent replications. Different letters indicate significant difference between treatments according to the least significant differences test at P < 0.05.