Transcriptional coordination of the aromatic amino acid metabolic network in Petunia and beyond

Plants produce vast arrays of specialized metabolites mediating ecological interactions, notably including phenylalanine-derived metabolites. Biosynthesizing these metabolites requires not only defined structural pathways, but also tight coordination between the shikimate pathway, aromatic amino acid production, and downstream specialized metabolism, such as benzenoid metabolism. Regulation occurs at multiple levels, including post-translational control of enzymes through mechanisms such as allostery, wherein binding of a regulatory metabolite alters catalytic activity. However, transcriptional regulation is also a flux control mechanism in these pathways and has increasingly been studied. Here, we summarize recent developments in this field. Petunia emerged as a key model for understanding how transcriptional networks regulate this metabolic system, complemented by discoveries in other species. Central to this regulation are MYB transcription factors, including PhODO1, PhEOBI, and PhEOBII, which coordinate the expression of genes involved in both precursor supply and volatile formation. These regulators operate within broad networks that integrate environmental signals, including light, circadian rhythms, temperature, and hormonal cues, through additional transcription factors. Developmental regulators, particularly MADS-box transcription factors, link floral organ identity with metabolism, ensuring scent production occurs within appropriate developmental stages and tissues. Beyond transcriptional and enzymatic regulation, accumulation and utilization are also influenced by post-synthetic processes, including glycosylation, intracellular sequestration, transport, storage, and export. Together, these elements form multilayered frameworks that coordinates primary and specialized metabolism, ultimately determining composition, accumulation, and utilization of specialized metabolites. Expanding this framework across plant species will be essential for understanding metabolic regulation and enabling targeted manipulation of aroma and stress-related traits in crops.