Low-magnification CLSM detection of NO with DAF-2 DA at different developmental stages of the olive flower. Projections of section stacks A: the presence of NO is shown by green fluorescence (arrows), which is clearly distinguishable from the tissues autofluorescence, showed here in red colour. Co-localization of both fluorescence sources results in yellow colour. Two different treatments are displayed (DAF-2 DA alone or in combination with cPTIO), as well as untreated samples (control). B: quantification of the fluorescence intensity owing to DAF-2 DA over the stigma surface. C: the same over the anther surface. Both the average and the standard deviation displayed in the graphs correspond to the measurement of a minimum of nine images, on three independent experiments. A: anther; AU: arbitrary units; O: ovary; P: petal; Pg: pollen grain; S: stigma; St: style.