Figure 7.

Quantitative analysis of S4B fluorescence intensity in leaf midribs. A and B, Wild type (WT), ppcesa3/8KO-86lox, and ppcesa3/8KO-86lox transformed with proCESA8::CESA expression vectors. For each rescue genotype, three independent genetic lines were sampled in triplicate and measured with six samples of the wild type (GD06) and eight samples of ppcesa3/8KO-86lox. A, For lines derived from transformation of ppcesa3/8KO-86lox with proCESA8::CESA3 (8pro:3R), proCESA8::CESA7 (pro8:7R), and proCESA8::CESA10 (pro8:10R) genotypes, the three independent lines did not differ significantly and were combined. proCESA8::CESA7 and proCESA8::CESA10 lines did not differ significantly from the parent double KO line (P > 0.05), whereas proCESA8::CESA3 lines had significantly higher fluorescence compared with the parent double KO line but significantly less than the wild type (P < 0.05). Error bars indicate se for three independent lines. Genotypes with different letters are significantly different (P < 0.05). B, For lines derived from transformation of ppcesa3/8KO-86lox with proCESA8::CESA5 (pro8:5R) and proCESA8::CESA4 (pro8:4R), the three independent lines were significantly different and were analyzed separately. proCESA8::CESA5 (5R) lines were not significantly different from the wild type (P > 0.05), except for 5R7, which was not significantly different from ppcesa3/8KO-86lox (P > 0.05). proCESA8::CESA4 lines did not differ significantly from ppcesa3/8KO-86lox (P > 0.05). Error bars indicate se for three gametophores from the same line (n = 3). Lines with different letters are significantly different (P < 0.05). C, Midrib fluorescence was slightly but significantly reduced in cesa4/10KO compared with the wild type (P = 0.037). Reduction in midrib fluorescence in cesa6/7KO was substantial and highly significant (P = 0.0011). Error bars indicate se for three independent mutant lines or three replicates of the wild type (n = 3). Genotypes with different letters are significantly different (P < 0.05).