Dissection of domain function for tandem AP2 plant transcription factors

Abstract: Oils are some of the most energy dense compounds produced in nature and play a vital role in society as a source of food, energy and as raw material in many chemical processes. Plant produced oils (triacylglycerols) are a key asset in the transition away from fossil oils. The progress made in recent years in molecular biology has greatly increased our understanding of plant oils biosynthesis. However, the regulatory mechanisms are not fully understood. Knowledge about these mechanisms could potentially lead to the development of new high yielding oil crops with tailored oil compositions. In this report, three related transcription factors associated with oil biosynthesis and embryo development: WRINKLED1 (WRI1), WRINKLED4 (WRI4), and BABY BOOM (BBM), are studied for their effect on oil biosynthesis in relation to their structure. To this purpose, two hybrid transcription factors (HTFs) were created by swapping the DNA binding domain of WRI1 with those of BBM and WRI4. The transcription factors were shown to have highly similar DNA binding domains, but only WRI1, WRI4 and WIR4 HTF induce oil production in leaf tissue. This report identifies two potential regions within the DNA binding domain that are possible explanations for the difference seen in binding selectivity between the factors.