Effect of MGD1 suppression on galactolipid biosynthesis in etiolated seedlings. A, Quantitative reverse transcription-PCR analysis of MGD1 mRNA levels in 4-d-old etiolated seedlings of amiR-MGD1 under +DEX and −DEX conditions. Data are presented as fold difference from the −DEX control after normalizing to the control gene ACTIN8. Data are means ± se from 13 (L4w) or three (L4g) independent experiments. B, Accumulation of MGDG and DGDG in 4-d-old etiolated seedlings of amiR-MGD1 L4w. C and D, Fatty acid composition of MGDG (C) and DGDG (D) in 4-d-old etiolated seedlings of amiR-MGD1 L4w. In B to D, data are means ± se from three independent experiments. Asterisks indicate significant differences from the −DEX control (*, P < 0.05; **, P < 0.01; and ***, P < 0.001, Student’s t test).