Figure 3.

Laccase activity in the cell walls of differentiated cell types in higher-order lac mutants. A, Activity of WT and Q using DAF as substrate at pH 4–7, expressed as relative substrate oxidation rates. Thin lines represent five individual replicates, thick lines are the overall average by local regression (LOESS). Activity in autoclaved sections was subtracted to show only LAC-mediated oxidation. B, Activity of WT and higher-order lac mutants using DAF as substrate at pH 5, expressed as relative substrate oxidation rates. C, Activity of WT and higher-order lac mutants using DAF as substrate at pH 5, expressed as relative substrate oxidation rates. Different letters indicate statistically significant differences between genotypes according to a Tukey-HSD test (per panel; α = 0.05); 20 measurements were taken for each cell type in each of n = 5 individual plants per genotype.