In order to obtain a cross section of a date palm leaflet, it was first precooled (4°C) and fixed with paraffin wax (Roti®-Plast (melting point 56-58°C) from Carl-Roth GmbH + Co. KG, Germany) in a histological sample holder. A 40 μm thick cross section was produced using a microtome (R Jung AG Heidelberg, Germany) and then placed with isotonic 0.9% NaCl (from Carl-Roth GmbH + Co. KG, Germany) water solution on a microscope slide and then covered with a cover glass.
For the acquisition of fluorescence images, a Keyence BZ-8100E fluorescence microscope (Keyence Corp., Osaka, Japan) equipped with a true colours CCD sensor (2/3”, 1.5 megapixels) was used. The following three filters sets (excitation, absorption) were used: DAPI-BP (320-400 nm, 410–510 nm), GFP-BP (430–510 nm, 485–585 nm), Texas-Red (520–600 nm, 570–690 nm) together with a zoom objective CFI Plan Apo VC 20X (Nikon Corp., Tokyo, Japan).
For the acquisition of fluorescence images, a Keyence BZ-8100E fluorescence microscope (Keyence Corp., Osaka, Japan) equipped with a true colours CCD sensor (2/3”, 1.5 megapixels) was used. The following three filters sets (excitation, absorption) were used: DAPI-BP (320-400 nm, 410–510 nm), GFP-BP (430–510 nm, 485–585 nm), Texas-Red (520–600 nm, 570–690 nm) together with a zoom objective CFI Plan Apo VC 20X (Nikon Corp., Tokyo, Japan).