Proteases and inhibitors in the interaction between Agrobacterium tumefaciens and Nicotiana benthamiana – systematic analysis and emerging solutions for molecular farming.
I joined the van der Hoorn lab in November 2014 as a DPhil student. I am studying plant immune responses to leaf infiltration with Agrobacterium tumefaciens. A. tumefaciens has the unique ability to genetically manipulate its host while living in the apoplast, the free diffusional space between plant cells. Therefore, this plant pathogen is widely used in research and industrial applications to produce recombinant proteins in Nicotiana benthamiana. Production of pharmaceutically useful recombinant (glycol-) proteins in agroinfiltrated plants (molecular farming) is a highly promising technology. However, the potential of molecular farming is currently limited by proteolytic degradation of recombinant proteins in planta, resulting in suboptimal protein yields. The immune response to A. tumefaciens results in activation of plant proteases that are involved in degradation of recombinant proteins. I therefore aim to obtain a comprehensive map of the proteolytic machinery in the apoplast of agroinfiltrated Nicotiana benthamiana. This includes transcriptomics and proteomics experiments as well as activity-based proteomics, which is pioneered in plants by the van der Hoorn lab.
Based on a comprehensive and detailed understanding of the plant immune response, including but not limited to proteases, I hope to develop strategies for overexpression of protease inhibitors, combined with silencing and disruption of protease genes, to minimize recombinant protein degradation in molecular farming.