[Perspective] Plant metabolons assembled on demand
The concept of a metabolon was first described in 1985 as a supramolecular assembly of enzymatic and structural components able to sequester and channel metabolic pathway intermediates (1). Initially, metabolons were proposed for the citric acid cycle, glycolysis, and nucleotide and amino acid biosynthesis as a mechanism to coordinate metabolic flux and reduce kinetic constraints. Although the theory is expedient and has aligned with a vast amount of evidence in support of protein-protein interactions, definitive proof that efficient cellular metabolism is associated with metabolon formation has been elusive. On page 890 of this issue, elegant work from Laursen et al. (2) provides a functional link between the dynamic interactions of metabolic enzymes and the production of the cyanogenic glucoside, dhurrin, in the cereal crop sorghum. Upon tissue damage by pests, dhurrin is hydrolyzed to toxic hydrogen cyanide as a plant defense mechanism. Authors: Mehran Dastmalchi, Peter J. Facchini