Multimodal Imaging of Arabidopsis Ovules

Images were obtained with Olympus FV1000, Leica SP8 and Zeiss LSM780NLO confocal microscopes. SR2200 was excited with a 405-nm laser line and emission recorded between 415 and 476 nm (405/415–476); similar settings were used to detect DAPI. For fluorescent proteins, the following excitation/emission wavelengths were used: CFP (458/473–552), GFP (488/505–540), YFP (514/517–597), dsRed variants (561/565–615). For spectral unmixing of SR2200 and DAPI, images were obtained with a Zeiss LSM780NLO confocal microscopes equipped with a 32-channel GaAsP array for spectral detection (405/410–695) and processed with Zeiss ZEN software. Individual staining of Arabidopsis ovules with only SR2200 or DAPI, respectively, was performed to obtain reference spectra. 3D reconstructions and orthogonal sections were produced with ImageJ software.