Figure 3.

Biochemical phenotype of the mgd1 mutant. (A) Lipid composition of wild-type and mutant leaves. Total leaf lipids were extracted and the different lipid classes were separated by TLC and quantified. Indicated lipids are monogalactosyl diacylglycerol (MGD), phosphatidylglycerol (PG), digalactosyl diacylglycerol (DGD), sulfolipid (SL), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). (B) MGD synthase and DGD synthase activities of wild-type and mutant chloroplasts. The rate of incorporation of [¹⁴C]galactose into galactolipids in isolated chloroplasts was determined. Units are pmol UDP-[¹⁴C]galactose/mg chlorophyll/min. (C) Fatty acid composition of MGD from wild-type and mutant leaves. MGD isolated in A above was subjected to fatty acid methyl ester quantification. (A–C) Presented values are means from three (wild type) or six (mgd1) independent measurements ± SE.