Metabolons in plant primary and secondary metabolism

Metabolons are multi-enzyme protein complexes composed of enzymes catalyzing sequential reactions in a metabolic pathway. Metabolons mediate substrate channeling between the enzyme catalytic cores to enhance the pathway reactions, to achieve containment of reactive intermediates, and to prevent access of competing enzymes to the intermediates. These provide unique advantages in metabolic regulation. The discovery of plant metabolons has been accelerated by the recent technical developments and a considerable number of metabolons involved in both primary and secondary metabolism have been indicated in the last decade. These findings related with plant metabolons are comprehensively reviewed in this review, indicating metabolome-wide engagement of metabolons. However, there are still unexplored frontiers remaining for further discovery of metabolons in plant metabolism. Pathways with high potential of novel metabolon and technical issues to be solved for the future discovery will also be discussed.