In order to solve the environmental problem that happens near us, our team chose to deal with the invasion of Kudzu in the United States, which will not only harm the normal agriculture of local plants but also will affect the other local properties, causing huge economic loss. In our original research, we thought that phytotoxin phaseolotoxin was only specific to kudzu plus other legumes and that the size of the target phaseolotoxin molecular is relatively large. But in the following discussion, our team found some concepts we used were wrong. As a result, we reread the related literature. In this process, we corrected some of our misunderstandings, found out the exact functions of each operon in the phaseolotoxin cluster (Aguilera, López-López, Nieto, Garcidueñas-Piña, Hernández-Guzmán, Hernández-Flores, Murillo& Alvarez-Morales, 2007), and gained a better understanding of the illicit transportation of phaseolotoxin in the bacterial Opp system.
In our project, our team expects to eliminate kudzu from the farmlands, power lines, and other places that have been invaded by kudzu in the United States. Many of the native plant species have been killed off due to their inability to compete with kudzu. The existing methods are mostly relatively useless for solving the problem permanently. This led us to the question of "How could we eradicate kudzu?". To tackle this question, we sought to use synthetic biology to come up with a method to control the growth of kudzu and reduce financial loss because of it.
For the wet lab design, we are going to use the E. coli system expression to produce phaseolotoxin. Due to the pandemic, we were not able to access our lab. This forced us to change our focus toward creating models to find a way to apply phaseolotoxin in the real environment instead of our lab and to ensure that its side effect on the environment would be minimized. With the help of other teams, our team made some improvements to the models.
The first model uses the cross-species transmission model from the University of North Carolina at Chapel Hill (Leer, 2005) (Fabiszewski, Umbanhowar, & Mitchell, 2010). The second model uses a Mass Action Kinetics as the model framework. NetLogo Model is mainly utilized for our third model (Aurambout & Endress, 2017).
Apart from that, we could not make any validation of the experiment to produce phaseolotoxin due to the pandemic, so we ran our different models to explain the purpose of our project, optimize the E.coli expression system and predict the financial cost for the future product. The Pathogen Transmission Model and the ROTCase Kinetics Model are finished while the Kudzu Management Cost Model is still under testing.
After our first research, we learned that phaseolotoxin is not actually specific to kudzu, which would cause unexpected safety problems as well as difficulty in producing phaseolotoxin. The other thing is some E.coli strains are resistant to phaseolotoxin, and some are not, which will be an important point for us when we want to choose the E.Coli expression system in the future.
In the future, as long as the conditions permit, we will keep working on the wet lab to try to produce the phaseolotoxin in our lab. For the dry lab, the parameters of those models created need to be further optimized. If the phaseolotoxin can be made successfully, we still need to work on how to gain commercial approval from authorities and how to educate the potential users to use the phaseolotoxin correctly. What’s more, the ecosystem may be another part that our team should pay more attention to once the kudzu is removed.
Aguilera, S., López-López, K., Nieto, Y., Garcidueñas-Piña, R., Hernández-Guzmán, G., Hernández-Flores, J. L., Murillo, J., & Alvarez-Morales, A. (2007). Functional characterization of the gene cluster from Pseudomonas syringae pv. phaseolicola NPS3121 involved in synthesis of phaseolotoxin. Journal of bacteriology, 189(7), 2834–2843. https://doi.org/10.1128/JB.01845-06
Aurambout, J., & Endress, A. (2017). A model to simulate the spread and management cost of kudzu (Pueraria montana var. lobata) at landscape scale. Retrieved October 27, 2020, https://www.sciencedirect.com/science/article/abs/pii/S1574954117301097?via=ihub
Fabiszewski, A., Umbanhowar, J., & Mitchell, C. (2010, March 01). Modeling landscape‐scale pathogen spillover between domesticated and wild hosts: Asian soybean rust and kudzu. Retrieved October 27, 2020, from https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/08-0820.1
Leer, S. (2005, April 25). Kudzu turning over new leaves in Indiana counties. Retrieved October 27, 2020, from https://www.purdue.edu/uns/html3month/2005/050425.Nice.kudzu.html