The emerging field of transport engineering of plant specialized metabolites.

From a biotechnological perspective transport processes represent attractive targets for modulation of metabolite levels and are the foundation for the emerging field of transport engineering. Potential applications of transport engineering include control of metabolite accumulation in a tissue-specific manner in crop plants as well as increased yields of commercially valuable compounds produced in synthetic biology approaches. Within specialized metabolism, recent advances include identification of not only vacuolar but now also plasma membrane-localized transporters and neo-functionalization of members of primary metabolite transporter families to include specific roles in transport of specialized metabolites. As glucosinolates are specialized metabolites of the model plant Arabidopsis, glucosinolate transport processes emerge as a model system for studying transport of specialized metabolites.