Fig. 2.

UGT80 and UGT713 mRNA expression in relation to SG levels in imbibed seeds. (A–D) Seeds were imbibed in water during a 24-hour time-course. Samples were taken at each time-point for RNA and lipid extractions in parallel experiments. Error bars denote standard deviations for n=3. Significant differences from the 0 hour time-point are indicated by an asterisk (two-tiered t-test, P≤0.05). (A) Quantitative real-time PCR was performed with cDNA synthesized from seed-derived RNA samples. Relative units normalized to the reference gene ARP6 are plotted on the Y-axis. UGT80A2 and UGT80B1, but not UGT713B1 mRNA transcripts are down-regulated after one hour of imbibition. (B–D) SG and polar lipids are quantified as percent total signal by ESI-MS/MS. Total SG content (B), including sitosteryl, stigmasteryl, and campesteryl glucosides (C) decreases upon seed imbibition, whereas total polar lipids (D) increase upon seed imbibition.