Figure 6.

FAH1 expression in the palisade is required for sinapoylmalate accumulation. A, FAH1 gene expression by counts per million (CPM) in FAC sorted palisade mesophyll and photosynthetic reference cell populations. Colored dots indicate values from the three paired replicates. B, Red fluorescent phenotype when viewed under UV light of fah1-7 mutants compared with Landsberg erecta (Ler) control plants grown for 17 days at 50 μmol m⁻² s⁻¹. C, Red fluorescent phenotype under UV light of fah1-7 mutants grown for 17 days at 50 μmol m⁻² s⁻¹ (low light grown, LL), or 7 days 50 μmol m⁻² s⁻¹ followed by 10 days at 300 μmol m⁻² s⁻¹ (high light grown, HL). D, Representative images of calcofluor white-stained first true leaf cross-sections of LL- and HL-grown fah1-7 mutant and control plants. Example palisade cells are outlined in red. E, Palisade mesophyll cell height to width ratio from the first leaf pair of plants grown as in (C) and (D). F, Representative fluorescence image of a leaf cross-section from a 17-day-old T1 plant carrying a IQD22_pro:FAH1-mCit transgene (n = 6). FAH1-mCit, green; chlorophyll autofluorescence, blue. G and H, Representative image (G) and quantification (H) of the relative change in red fluorescence of T1 generation 17-day-old LL-grown fah1-7 mutant plants carrying transgenes driving either FAH1-mCit or a control cDNA (GUS-mCit) under the IQD22 promoter. P = 0.006, paired t test. Scale bar (G): 5 mm. In (D) and (F), scale bars: 50 μm; adaxial is up. In (E) and (H), boxes indicate 25th and 75th percentiles, horizontal lines the median. Tukey whiskers are shown.