Figure 2

Comparison of wall ingrowths in PP TCs of Arabidopsis leaf minor veins by confocal imaging and SEM. A, D. SEM views of fresh leaf material torn paradermally then subjected to bleach extraction and viewed by SEM. B, C, E, F. Confocal imaging of minor veins from leaf material stained by the mPS-PI procedure. A. SEM image of a PP TC showing a central band of reticulate wall ingrowth material (arrows). B. Highly localized deposition of wall ingrowth material seen as a central band (arrows) running along the length of each PP TC (asterisks). The focal plane of the image passes from the PP TC on the right (double asterisk) into the underlying SE, indicating how the band of wall ingrowth material superimposes the underlying SE. C. Confocal image at higher magnification showing substructure (arrow) of the wall ingrowth material in a PP TC (asterisk). In this image the SE to the left of this PP TC is obscured. D. SEM view of a minor vein junction of two PP TCs showing examples of isolated patches of wall ingrowth deposition (arrows). E. Confocal image of minor vein junction showing discrete patches of wall ingrowth deposition (arrows). F. Higher magnification confocal image showing patches of wall ingrowth deposition (arrows) in two PP TCs (asterisks). BS, bundle sheath cell; CC, companion cell; SE, sieve element. Scale bars = 2 μm in A and D. Scale bars = 10 μm in B and E. Scale bars = 5 μm in C and F. The image in A is reproduced in part from Edwards et al. [22].