Abstract
Seeds contain a large quantity of oils, which are mainly constituted of triacylglycerol (TAG), a fundamental source of carbon and energy. TAG biosynthesis is catalyzed by a series of multiple enzymes. In particular, two key enzymes catalyzing the last acylation step for TAG production, acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) and phospholipid:diacylglycerol acyltransferase 1 (PDAT1), are rate-limiting enzymes that determine TAG accumulation in Arabidopsis seeds. We recently showed that the two enzymes are transcriptionally coordinated by the R2R3-type MYB96 transcription factor to promote TAG assembly during seed maturation in Arabidopsis. Here, we further found that DGAT1 and PDAT1 physically associate, possibly to enhance the efficiency of TAG production. Overall, our findings suggest that TAG biosynthesis is intricately regulated at multiple levels, and these molecular strategies can potentially be used for metabolic engineering in plants.