Localization of ZmDUR3/GFP fusion proteins in tobacco protoplast. (a) Co-localization of ZmDUR3-GFP and plasma membrane localized AtPTR1-YFP, (b) GFP-ZmDUR3 and AtPTR1-YFP, and (c) free GFP. Fluorescence was detected using a confocal laser-scanning microscope: bright-field images (first column), chlorophyll fluorescence (red signal, second column), GFP-fluorescence (green signal, third column); YFP-fluorescence (purple signal, as control for plasma membrane localization, fourth column) are shown. In the last column, merged images show chlorophyll fluorescence (red), GFP-fluorescence (green) and YFP-fluorescence (purple). Diameter of protoplasts was approximately 40 μM.