Molecular Basis of Plant Oil Biosynthesis: Insights Gained From Studying the WRINKLED1 Transcription Factor

Abstract

Most plant species generate and store triacylglycerol (TAG) in their seeds, serving as a core supply of carbon and energy to support seedling development. Plant seed oils have a wide variety of applications, from being essential for human diets to serving as industrial renewable feedstock. WRINKLED1 (WRI1) transcription factor plays a central role in the transcriptional regulation of plant fatty acid biosynthesis. Since the discovery of Arabidopsis WRI1 gene (AtWRI1) in 2004, the function of WRI1 in plant oil biosynthesis has been studied intensively. In recent years, the identification of WRI1 co-regulators and deeper investigations of the structural features and molecular functions of WRI1 have advanced our understanding of the mechanism of the transcriptional regulation of plant oil biosynthesis. These advances also help pave the way for novel approaches that will better utilize WRI1 for bioengineering oil production in crops.

Genome-Wide Mapping of Histone H3 Lysine 4 Trimethylation (H3K4me3) and Its Involvement in Fatty Acid Biosynthesis in Sunflower Developing Seeds

“…WRI1 belongs to the APETALA 2 transcription factor family and is a regulator of plant oil biosynthesis [ 25 ]. Although WRI1 has been described and functionally characterized in different plants, including Brassica napus , Camelina sativa , Persea americana , Ricinus communis , and Jatropha curcas [ 75 , 76 , 77 , 78 , 79 ], among other species, the function of WRI1 in sunflower seeds is not well characterized.…”

“…WRI 1 is a member of the APETALA2/ethylene-responsive element binding (AP2/EREBP) proteins family [ 24 ]. This transcription factor not only activates the expression of FA synthesis-related genes but also promotes the expression of several glycolytic enzymes directing the carbon flux toward the oil synthesis [ 25 ]. The function of this transcription factor is conserved in Arabidopsis, Zea mays , B. napus, and other species [ 26 ].…”

Intrinsic Disorder in Plant Transcription Factor Systems: Functional Implications

“…The IDR allows exposure of the PEST motif to protein kinases and phosphorylation with structural consequences, finally affecting WRI1-mediated plant oil biosynthesis. This suggests a strategy to increase accumulation of oils in plant tissues through WRI1 engineering [ 211 , 212 ].…”

The Pumilio RNA‐binding protein APUM24 regulates seed maturation by fine‐tuning the BPM‐WRI1 module in Arabidopsis

“…These TFs include three B3 domain proteins, LEAFY COTYLEDON2 (LEC2), ABSCISIC ACID INSENSITIVE3 (ABI3), and FUSCA3 (FUS3), as well as an unusual nuclear factor YB (NF‐YB) subunit of the NF‐Y CCAAT‐binding TF, LEAFY COTYLEDON1 (LEC1) (Gutierrez et al, 2007; Suzuki and Mccarty, 2008). In addition, WRINKLED1 (WRI1), a member of the APETALA2 (AP2) TF family, plays an important role in seed development by activating the genes encoding key enzymes involved in seed oil biosynthesis (Focks, 1998; Baud et al, 2007; Maeo et al, 2009; Ma et al, 2013; Kim et al, 2016; Kong et al, 2020a, 2020b). The WRI1 loss‐of‐function mutant wri1‐1 produces wrinkled seeds with an 80% lower seed oil content compared to the wild type (WT) but shows no obvious phenotypic defects during vegetative growth (Baud et al, 2007; Ma et al, 2013).…”

“…Several studies have focused on the phosphorylation‐mediated stabilization and degradation of WRI1 (Chen et al, 2013; Ma et al, 2015, 2016; Zhai et al, 2017; Kong et al, 2020b). WRI1 degradation is mediated by the 26S proteasome via interactions with multiple BTB/POZMATH (BPM) proteins, which function as CULLIN3‐based E3 ligase adaptors (Chen et al, 2013).…”