Figure 6.

A Small Loop between TM4 and TM5 Is Responsible for the Difference in Functionality of BdTGD1 in Arabidopsis tgd1-1.

(A) Series of chimeric proteins generated for identification of functional-divergence between AtTGD1 and BdTGD1. AtTGD1 sequences are gray; BdTGD1 sequences are white. The red box indicates L45, which gives rise to the functional differences between AtTGD1 and BdTGD1.

(B) Ratios of C18:3/16:3 in total lipids of Arabidopsis leaf tissues. Total lipids were extracted from 4-week-old Arabidopsis leaves. The molar percentages of individual FAs relative to total FAs in each lipid species were quantified using GC-FID of FAMEs. Representative individual plants from three independent lines for each construct (as shown in Supplemental Figure 14) were averaged, and the error bars represent sd. Significant differences compared with the wild type are indicated (Student’s t test): *P < 0.05 and **P ≤ 0.01.

(C) Thin-layer chromatography analysis of polar lipids of a single representative plant for each construct is shown. Glycolipids were visualized by α-naphthol staining. TGDG is indicated.