Figure 5.

Necrosis induction and H₂O₂ generation in transgenic Col-0 plants expressing HL2b. A, Necrotic symptoms in the leaves of transgenic plants expressing HL2b (Col-HL2b). WT, Wild-type Col-0. B, Western-blot analysis of the 2b protein in the transgenic plants. Total proteins (30 μg), which were extracted from Col-0 (WT), CMV-infected leaves (Y1H2Y3), and Col-HL2b (lines 1, 6, and 7), were separated by SDS-PAGE and blotted onto a polyvinylidene difluoride membrane. The blots were then subjected to immunodetection using anti-2b antibodies. C, Detection of H₂O₂ in the Col-HL2b lines using the H₂O₂-sensitive fluorescent probe H₂DCFDA. Note that necrosis on the edge of the leaves that were harvested from the transgenic plants was associated with fluorescent spots. Leaves were harvested and photographed using either bright-field light microscopy (BF) or fluorescence microscopy (H₂O₂). D, Catalase activities in the Col-HL2b lines. Catalase activity was determined as described for Figure 4.