4.6. GFP and mRFP Imaging

GFP and mRFP fluorescence in the inoculated leaves was monitored by illumination with a handheld UV source (DESAGA, Wiesloch, Germany). At higher magnifications, GFP fluorescence was detected using an LSM510 confocal laser scanning microscope (Zeiss, Jena, Germany). The excitation wavelengths for GFP and mRFP were 488 nm and 555 nm, respectively. The detection window was 500–550 nm for GFP and 590–650 nm for mRFP. Unless otherwise indicated, the lower epidermal cells of injected leaves were observed at 72 hpi.