Figure 4.

Incorporation of Ser into thiols in wild-type and transgenic plants with reduced mitochondrial SAT activity. Eight-week-old transgenic plants with reduced mitochondrial SAT activity (amiSAT3 lines 4 and 5; gray bars) were tested for incorporation of [³H]Ser into Cys and glutathione (GSH). Wild-type plants of the same age (Col-0 A) and of the same developmental stage (Col-0 B; 6 weeks old) as the analyzed amiSAT lines served as controls (black bars). All plants were grown on soil under the same conditions as plants used for analysis of metabolites, transcript levels, and protein abundance. Samples of three individuals of wild-type and transgenic plants were taken and analyzed for incorporation of the radioactive label from [³H]Ser into thiols after 20 and 30 min according to Heeg et al. (2008). Error bars indicate sd, and asterisks mark significant differences from both wild types using the unpaired t test.