Fig. 7.

Fluorescence in situ hybridization with PoptrCAD10 probes on the third day of root growth. Hybridization signal in the cells of stage 1 is visible as yellow fluorescence (A; Alexa 546, arrows). DAPI staining (B) was used to detect nuclei, and bright field imaging (C) as well as Safranin and Fast Green staining (D) were used to visualize mature xylem cells with secondary cell walls (black arrowheads). Note the lack of hybridization signal in the developed tracheary elements – cells of stages 2 and 3 (arrowhead). Scale bars = 50 μm.