Figure 9.

Detection of NO in wild type and mutant vertically grown Arabidopsis root apices without and with PQ treatment (0.1 or 1 µM). NO content was measured by the fluorescence probe DAF-FM-DA (4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate) (A, scale bar: 100 µm) and expressed as pixel intensity (B). DAF-FM fluorescence was measured at two identical regions, cc. 200 µm and 500 µm far away from the root tips and averaged (see Figure 7). See that 1 µM PQ concentration reduced the NO content of the Atcrk5-1 mutant to the wild type level. Bars indicate ±SE of measurements performed with at least 20 seedlings per each line. p-values were calculated with two-tailed Student’s t-test (* p ≤ 0.1; *** p ≤ 0.001). Two biologically independent experiments were carried out with similar statistical results.