Figure 1.

Images of reflected light (a) and fluorescence parameters (b–e) from stomatal guard cells and surrounding mesophyll in a tradescantia leaf. Images of F′ taken using a 695-nm longpass filter (b) or a 680-nm bandpass filter (c); images of F_q′/F_m′ taken using a 695-nm longpass filter (d) or a 680-nm bandpass filter (e). Values of F_q′/F_m′ for guard cell chloroplasts can be determined from images d and e by isolating the chloroplasts using the FluorImager software (see “Materials and Methods”; Oxborough and Baker, 1997).