Functional Characterization of Avocado WRINKLED1 and WRINKLED2 in Non-Seed Oil Biosynthesis.
Abstract
WRINKLED1 (WRI1) is a key transcription factor regulating oil biosynthesis in plant seeds, yet the mechanisms underlying high oil accumulation in non-seed tissues and the functional roles of WRI paralogs remain poorly understood. Avocado (Persea americana), a basal angiosperm, provides a unique system to address these questions, as its mesocarp accumulates exceptionally high levels of oil (60–70% of dry weight), predominantly composed of oleic acid. Here, we show that both PaWRI1 and PaWRI2 are functionally active regulators of lipid metabolism. Transient expression in Nicotiana benthamiana leaves demonstrated that PaWRI1 and PaWRI2 enhance lipid droplet formation and triacylglycerol (TAG) accumulation, with the strongest effects observed when both factors were co-expressed. qRT-PCR analysis revealed selective upregulation of plastidial glycolytic and fatty acid biosynthetic genes, with co-expression leading to greater induction of several key genes than either factor alone. Yeast one-hybrid assays further demonstrated that PaWRI1 and PaWRI2 directly bind AW-box and AW-like promoter elements of lipid metabolic genes. PaWRI2 was found to be both self-activated and activated by PaWRI1, indicating an interdependent regulatory relationship in non-seed tissues. Building on these findings, microscale thermophoresis (MST) assays will be used to quantitatively determine the DNA-binding affinities of recombinant PaWRI1 and PaWRI2 for AW-box elements, providing mechanistic insight into WRI-mediated transcriptional control of lipid biosynthesis. This work establishes PaWRI2 as a functional transcriptional regulator of oil biosynthesis and advances our understanding of WRI-mediated control of lipid metabolism in non-seed tissues.
Start Time
15-4-2026 11:00 AM
End Time
15-4-2026 12:00 PM
Room Number
303
Presentation Type
Oral Presentation
Presentation Subtype
Grad/Comp Orals
Presentation Category
Science, Technology, and Engineering
Student Type
Graduate
Faculty Mentor
Aruna Kilaru
Functional Characterization of Avocado WRINKLED1 and WRINKLED2 in Non-Seed Oil Biosynthesis.
303
WRINKLED1 (WRI1) is a key transcription factor regulating oil biosynthesis in plant seeds, yet the mechanisms underlying high oil accumulation in non-seed tissues and the functional roles of WRI paralogs remain poorly understood. Avocado (Persea americana), a basal angiosperm, provides a unique system to address these questions, as its mesocarp accumulates exceptionally high levels of oil (60–70% of dry weight), predominantly composed of oleic acid. Here, we show that both PaWRI1 and PaWRI2 are functionally active regulators of lipid metabolism. Transient expression in Nicotiana benthamiana leaves demonstrated that PaWRI1 and PaWRI2 enhance lipid droplet formation and triacylglycerol (TAG) accumulation, with the strongest effects observed when both factors were co-expressed. qRT-PCR analysis revealed selective upregulation of plastidial glycolytic and fatty acid biosynthetic genes, with co-expression leading to greater induction of several key genes than either factor alone. Yeast one-hybrid assays further demonstrated that PaWRI1 and PaWRI2 directly bind AW-box and AW-like promoter elements of lipid metabolic genes. PaWRI2 was found to be both self-activated and activated by PaWRI1, indicating an interdependent regulatory relationship in non-seed tissues. Building on these findings, microscale thermophoresis (MST) assays will be used to quantitatively determine the DNA-binding affinities of recombinant PaWRI1 and PaWRI2 for AW-box elements, providing mechanistic insight into WRI-mediated transcriptional control of lipid biosynthesis. This work establishes PaWRI2 as a functional transcriptional regulator of oil biosynthesis and advances our understanding of WRI-mediated control of lipid metabolism in non-seed tissues.
