Fig. 4.
ROS and NO sources during free pollination. Confocal laser scanning microscope images of stigmas from pistils at stage III incubated with specific enzyme activity inhibitors. (A) Detection of O2˙− by the specific probe DHE in an untreated stigma. (B) Stigmas pretreated with the NADPH oxidase inhibitor DPI before O2˙− detection. (C) Detection of O2˙− by the specific probe DHE in a stigma pretreated with the peroxidase inhibitor sodium azide. (D) Detection of NO by DAF2-DA in an untreated stigma. (E) Stigma pretreated with the specific nitric oxide synthase inhibitor L-NAME before NO detection. (F, G) Histograms showing relative fluorescence intensities quantified in total images of the stigmal lobules and corresponding to O2˙− and NO, reflecting the effect of enzyme-activity inhibitors. Different letters indicate significant difference at P <0.05 according to Duncan's multiple-range test. PC, papillar cells; SR, subpapillar region. Pollen grains (arrows). Bars=50 μm. (This figure is available in colour at JXB online.)