Figure 8.

Compromised lipid transfer from the ER to plastids in both lacs4 lacs9 double mutants. A, In vivo pulse-chase acetate labeling of MGDG. Detached leaves of the wild type (WT) and both lacs4 lacs9 double-mutant lines were floated on buffer containing [¹⁴C]acetate for 1 h before they were chased for the times indicated. Leaf material was collected, and lipid extracts were prepared and separated by two-dimensional TLC. The developed TLC plate was exposed to imaging plates, and the radiolabeled MGDG was quantified using a phosphorimager. B, In vivo pulse-chase labeling of lipids using [¹⁴C]oleic acid. The experimental setup was similar to that described for the labeling by acetate. The incorporation of radiolabeled oleic acid into the lipid classes PC, MGDG, and DGDG is shown for the wild type compared with both lacs4 lacs9 double-mutant lines. Each value represents the mean of three independent replicates. Error bars indicate sd.