Protein Structure, Evolution and Regulation of CER3, a Core Enzyme Partitioning Carbon into Two Specific Wax Biosynthetic Pathways

Cuticular wax is a critical component of the plant cuticle, playing an indispensable role in plant growth, development, and defense against environmental stresses. ECERIFERUM3 (CER3), a very-long-chain fatty acyl-CoA reductase, serves as a pivotal hub channeling carbon resources into the alkane- and alcohol-forming pathways respectively. Here, we systematically characterized the protein structural features and evolutionary patterns of CER3. We also comprehensively reviewed the multiple regulatory mechanisms governing CER3, encompassing transcriptional, post-transcriptional, translational, and epigenetic modifications, with particular emphasis on the definitive finding that CER3 modulates cuticular wax biosynthetic flux by assembling distinct protein complexes. Finally, existing knowledge gaps and future research directions are also discussed.