Plant BioMEMs

Plant BioMEMs is a new field of cellular manipulation. The idea is to integrate plant cells into a Lab-on-Chip device to administer gradients or to combine different cell types by a microfluidic flow to simulate the interaction of cells in a real tissue. A promising application of this strategy is metabolic engineering. Metabolic engineering means that a metabolic pathway is diverted at branching points, either by blocking a branch (downregulation of a gene) or by activating a branch (upregulation of a key enzyme). Plants are extremely proficient with respect to secondary metabolism. Many of these metabolites are of medical interest. To produce them in cell culture (so called plant cell fermentation) would be promising. There is a drawback, however: plant cell cultures are reluctant to unfold their metabolic potency, because they consist of only one cell type - in real tissues, several cell types work together and produce different steps of the pathway, similar to the division of labour in a factory.

Your task will be to design a strategy for metabolic engineering to maximise the production of nornicotine, an alkaloid with activity against Alzheimer. You have a microfluidic bioreactor that allows you to cultivate up to different cell types in a row connected by medium flow. You want to channel the entire pathway towards nornicotine, which requires suppression of the pathways diverting to anatabine and anabasine.

1. which genes would you knockdown (by an antisense strategy)?
2. which genes would you overexpress

• Here you find some unpublished material (protected by password) on the BMBF project, where we are dealing with this topic