Figure 2.

BRI1-GFP is expressed ubiquitously during early seedling development and is localized to the plasma membrane. A BRI1::GFP fusion protein was expressed from the BRI1 promoter in stably transformed wild-type Arabidopsis. A, Background chlorophyll fluorescence in a wild-type hypocotyl; B, BRI1::GFP fluorescence along the cell surface of hypocotyl cells; C, background fluorescence of a wild-type Arabidopsis root; D, BRI1::GFP at the cell surface in young root; E, BRI1::GFP at the cell surface in cotyledon epidermal cells (wild type has only stomata and guard cell chloroplast autofluorescence, which is not shown); F, BRI1::GFP localizes with the cytoplasm if cells are collapsed in 0.8 m mannitol, indicating that BRI1::GFP is in the plasma membrane. Bar = 20 μm.