EAGER: Non-integrative transient delivery of reagents into plant cells via the type IV secretion system of A. tumefaciens

Innovations developed through public sector investments over the past few decades have translated to technologies that have benefited U.S. agriculture productivity significantly, for example, reducing agriculture inputs through precision application of water, nutrients, and pesticides. Genetic technologies have led to better predictive models for plant breeding and introduction of novel traits into crops that could not be added by conventional means. However, the ability to introduce novel traits using biotechnology is often hampered by low efficiencies. This project seeks to improve the efficiency with which Agrobacterium tumefaciens can serve as a tool to introduce novel traits into crop plants by exploiting the bacterium's ability to secrete proteins into plant cells. The transient delivery of these proteins will impact both the ability of the plant cell to detect and fight off the bacterium, and the ability of the plant cell to regenerate a new plant once it has been altered. To meet this goal, a multidisciplinary approach will be taken that brings together expertise in genetics, microbiology and molecular biology. Importantly, the underlying biology of the project will be communicated through outreach efforts to the non-science community on all aspects of food production and on how innovations in agriculture help maintain the U. S. strategic advantage through its capacity to produce a plentiful and safe food supply. <br/><br/>The research to be conducted in this project lays out an innovative set of studies to design and test novel Agrobacterium tumefaciens strains that can help mitigate two major inefficiencies of plant transformation: the competency of the cell to receive a genetic reagent and the ability of that same cell to lead to germline transmission of the induced genetic change. Pseudomonas effector proteins that suppress the plant innate immune response will be transiently expressed to improve the efficiency of gene transfer from bacterium to plant cell. In addition, plant morphogenic proteins will be transiently expressed to improve the efficiency of regenerating plants from transformed tissue culture cells. The results of these studies will also provide insight into the size limit of a protein that can be shuttled through the Agrobacterium type IV secretion system. Overall, this project should lead to A. tumefaciens strains with enhanced transformation capacity across a broader array of genotypes within a plant species and that are easily transferable to the plant science community.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.