Manipulation of plant metabolic pathways by transcription factors

Plant metabolites are produced through complex processes that include multiple enzymatic steps, branched pathways and regulation by a number of functionally redundant transcription factors. In addition, plants synthesize and accumulate each metabolite, especially secondary metabolites, in specific tissues and cells during development. Therefore, manipulation of both transcription factors that regulate enzymatic steps of a metabolic pathway (metabolic regulators) and/or that regulate cellular differentiation (developmental regulators) would be an effective strategy for controlling plant metabolites, quantitatively and qualitatively. In this review, we describe the advantages of using transcription factors for metabolic engineering in plants. Transcriptional activators and repressors, including the chimeric repressors generated by CRES-T, are useful tools for the genetic engineering of metabolic pathways. In addition, we propose that the use of both developmental regulators and plant tissue culture technology, in combination with metabolic regulators, would be an effective strategy to increase the productivity of metabolites. We summarize the strategies that have been applied for the detection of regulators and enzyme genes involved in metabolic pathways.