Person:

Inniss, Mara Christine

Background: Plant biotechnology can be leveraged to produce food, fuel, medicine, and materials. Standardized methods advocated by the synthetic biology community can accelerate the plant design cycle, ultimately making plant engineering more widely accessible to bioengineers who can contribute diverse creative input to the design process. Results: This paper presents work done largely by undergraduate students participating in the 2010 International Genetically Engineered Machines (iGEM) competition. Described here is a framework for engineering the model plant Arabidopsis thaliana with standardized, BioBrick compatible vectors and parts available through the Registry of Standard Biological Parts (http://www.partsregistry.org). This system was used to engineer a proof-of-concept plant that exogenously expresses the taste-inverting protein miraculin. Conclusions: Our work is intended to encourage future iGEM teams and other synthetic biologists to use plants as a genetic chassis. Our workflow simplifies the use of standardized parts in plant systems, allowing the construction and expression of heterologous genes in plants within the timeframe allotted for typical iGEM projects.

Synthetic biology aims to engineer biological systems to meet new challenges and teach us more about natural biological systems. These pursuits range from the building of relatively simple transcriptional circuits, to engineering the metabolism of an organism, to reconstructing entire genomes. While we are still emerging from the foundational stages of this new field, we are already using engineered cells to discover underlying biological mechanisms, develop new therapeutics, and produce natural products. In this dissertation, we discuss the application of synthetic biology principles to the development of memory and pulse-detecting genetic circuits. In Chapter 2, we use novel transcriptional positive-feedback based memory devices integrated in human cells to study heterogeneous responses to cellular stresses. We built doxycycline, hypoxia, and DNA damage sensing versions of the device, demonstrating its modularity. In Chapter 3, we discuss further applications of the memory device in the study of long-term responses to hypoxia, gamma radiation, and inflammation. Finally, in Chapter 4 we describe work leading to the future construction of a pulse-detecting genetic circuit integrated in the E. coli genome. The work presented here illustrates the general applicability of synthetic biology in the study of biological phenomena and brings us one step closer to achieving a more exquisite understanding and control of natural systems.