Figure 7

Semi-quantitative analysis of wall ingrowth deposition in PP TCs of leaf minor veins in Arabidopsis following defoliation. A. All leaves except leaf 9, 10, and 11 were removed from 3 week-old plants. The picture shows a control plant (left) and a defoliated plant (right) at the beginning of the experiment. B. Control (left) and defoliated plant (right) after 5 days additional growth. C. Minor vein in leaf 10 from control plant. No wall ingrowth deposition is seen in PP TCs (asterisks). D. Minor vein in leaf 10 from control plant showing early stage wall ingrowth deposition (arrows) in a PP TC (asterisk). E. Wall ingrowth deposition seen as discrete clusters (arrows) in a PP TC (asterisk) in leaf 10 of defoliated plant. F. Denser clusters of wall ingrowth deposition (arrow) in leaf 10 of defoliated plant. G. Extensive wall ingrowth deposition (arrows) in PP TCs (asterisks) in vein near the tip of leaf 10 from a defoliated plant. BS, bundle sheath; CC, companion cell. Scale bars = 5 μm in D, E, F and G. Scale bar = 10 μm in C. H. Semi-quantitative analysis of defoliation on wall ingrowth deposition in PP TCs of leaf 10 measured in control and defoliated plants 5 days after defoliation. Wall ingrowth deposition in PP TCs is greatly enhanced as a consequence of defoliation, with this response being maximal in minor veins from the middle region of the leaf. Data shows mean ± SE of scores for wall ingrowth deposition in arbitrary units (AU); n = 4.