Figure 9.

Representative imaging of superoxide radicals and H₂O₂ productions in Phaseolus vulgaris L. leaves by CLSM. Images are developed from several optical sections collected by confocal microscopy showing the autofluorescence (blue; excitation at 633 nm, emission at 680 nm) and fluorescence due to DHE and DCF-DA. A–E, (I) superoxide-dependent DHE fluorescence (red) in leaf cross sections from mother control (A) and arsenic (As)-treated (B–K) leaves; (B) As-treated sodPv 1 mutant, (C) As-treated mother plants, (D) for the negative control, leaves were incubated with 1 mm TMP, a superoxide scavenger, (E) magnified view of leaf mesophyll with red fluorescence and autofluorescence, (I) red fluorescence in leaf section of double mutant, F–H, J, and (K) H₂O₂-dependent DCF-DA fluorescence (green) in leaf cross sections; (F) MC leaves, (G) As-treated mother plants, (H) As-treated sodPv 2 mutant, (J) green fluorescence in leaf tissues along with epidermal hair of double mutant, (K) as a negative control, and leaves were incubated with 1 mm ascorbate (ASC), which acts as a H₂O₂ scavenger. The results are representative of at least three independent experiments. Ep: Epidermis; Hr: hair; Ms: mesophyll cells; Scl: sclerenchyma; Xyl: xylem vessels. Bars = 50 μm.