Class A PpCESAs differ in their ability to rescue the ppcesa6/7KO phenotype. Quantitative analysis of S4B fluorescence in WT, ppcesa6/7KO-7A-lox (6/7KO), and ppcesa6/7KO-7A-lox transformed with PpCESA7pro:PpCESA expression vectors (denoted by PpCESA number and line number, separated by “R” to indicate attempted rescue). For each rescue genotype, three independent genetic lines were sampled in triplicate and measured with three samples each of WT and ppcesa6/7KO-7A-lox. Boxes show the means (center line) and the 95% confidence intervals (standard error of the mean) and whiskers indicate the ranges. Blue bars indicate means that are significantly different from WT, but not ppcesa6/7KO. Magenta bars indicate means that are significantly different from ppcesa6/7KO, but not WT. Medium gray bars indicate means that are significantly different from WT and ppcesa6/7KO. Light gray bars indicate means that do not differ significantly from WT or ppcesa6/7KO (Student’s t test, 0.05 P-value cutoff).