Plasticity of specialized metabolism as mediated by dynamic metabolons

The formation of specialized metabolites enables plants to respond to biotic and abiotic stresses, but requires the sequential action of multiple enzymes. To facilitate swift production and to avoid leakage of potentially toxic and labile intermediates, many of the biosynthetic pathways are thought to organize in multienzyme clusters termed metabolons. Dynamic assembly and disassembly enable the plant to rapidly switch the product profile and thereby prioritize its resources. The lifetime of metabolons is largely unknown mainly due to technological limitations. This review focuses on the factors that facilitate and stimulate the dynamic assembly of metabolons, including microenvironments, noncatalytic proteins, and allosteric regulation. Understanding how plants organize carbon fluxes within their metabolic grids would enable targeted bioengineering of high-value specialized metabolites.