Figure 4

Reactivation of transgene expression from the post-transcriptionally silenced E82 locus after exposure toGFP-COP1C73.Epifluorescence micrographs of whole-mounted seedlings are shown. Note that GFP-COP1 protein accumulates in the form of a single inclusion body per cell. Left column (panels一个,D, G,andJ): Control: Progeny of aGFP-COP1E82 hemizygous plant. GFP-COP1 was active only in the root. Central column (panelsB, E, H,andK): Progeny of aGFP-COP1C73 × E82 di-hybrid plant. GFP-COP1 was often active in the root, cotyledon, and first and second sets of leaves. Arrows highlight the reactivatedGFP-COP1in the cotyledon, leaf epidermis, as well as in trichomes of the second set of leaves. Right column (panelsC, F, I,andL): Control: Progeny of aGFP-COP1C73 hemizygous plant. GFP-COP1 was active in the root and in guard cells (note paired dots) of the cotyledon.