Kudzu
Kudzu’s tenacity stems from an extensive root system, climbing nature, large biomass turnover every growing cycle, and an ability to fix atmospheric nitrogen. Kudzu is also known to strangle or completely shade out plants growing in close proximity. In addition to these factors, kudzu contains active isoflavones, which is common in most legumes, and adds large amounts of litter to the soil, which interfere with the growth of some plants, including Bidens pilosa (Black-jack) and Lolium perenne (ryegrass). Pine oak acorns and some vegetables cannot survive near kudzu because the kudzu leaf extract has a strong inhibitory effect on germination. Due to these factors, only a few plants can survive in environments with kudzu.
Removal of Kudzu
In order to remove kudzu, farmers and power companies often have to spray harmful chemicals on their land. These chemicals, along with many other kudzu removal options, are expensive and can pose harmful effects to human health and the ecosystem.
Phytotoxin Phaseolotoxin
However, one strain of the bacterium Pseudomonas syringae has been found to specifically affect legumes by producing the phytotoxin phaseolotoxin (Lambert, 2019). Phytotoxin Phaseolotoxin can be cloned and expressed in E. coli. Phytotoxin Phaseolotoxin is a safer alternative solution to other toxins since it does not pose severe harm to humans, animals, crops, or the environment.
Goal
Our team plans to replicate the phaseolotoxin production pathway in E. coli and utilize the toxin as a more environmentally friendly option to remove kudzu. After the removal of kudzu, local endangered species can regrow without competition.
Models
Additionally, we developed three models to simulate the spread of infectious plant diseases:
- Asian Soybean Rust using kudzu as a vector (Fabiszewski et al., 2010)
- Simulate the ROTCase production and activity under promoters with different strengths
- Predict the spread and management cost of kudzu in a local area (Aurambout & Endress, 2018).
References
Aguilera, S, Torre-Zavala, SD, Hernandez-Flores, JL, Murillo, J, Bravo, J, and Alvarez-Morales, A (2012). Expression of the Gene for Resistance to Phaseolotoxin (argK) Depends on the Activity of Genes phtABC in Pseudomonas syringae pv. phaseolicola. PLOSone 7(10):e46815
Aguilera, S, Lopez-Lopez, K, Nieto, Y, Garciduenas-Pina, R, Hernandez-Guzman, G, Hernandez-Florez, JL, Murillo, J, and Alvarez-Morales, A (2007). Functional Characterization of the Gene Cluster from Pseudomonas syringae pv. phaseolicola NPS3121 Involved in Synthesis of Phaseolotoxin. J Bacteriol. 189(7):2834-2843. Doi: 10.1128/JB.01845-06
Bachmann, P. D. A., Xu, R., Ratnapala, L., & Patil, S. (2004). Inhibitory effects of phaseolotoxin on proliferation of leukemia cells hl-60, k-562 and l1210 and pancreatic cells rin-m5f. Leukemia research, 28, 301–6. https://doi.org/10.1016/j.leukres.2003.07.002
Ferguson, A., & Johnston, J. (1980). Phaseolotoxin : Chlorosis, ornithine accumulation and inhibition of ornithine carbamoyltransferase in different plants. Physiological Plant Pathology, 16 (2), 269–275.https://doi.org/https://doi.org/10.1016/0048-4059(80)90041-7
Guertin, Patrick & Denight, Michael & Gebhart, Dick & Nelson, Linda. (2008). Invasive Species Biology, Control, and Research. Part 1: Kudzu (Pueraria montana). 24.
Lambert iGEM Team. (2019). Hardware: Open Cell. Retrieved from https://2019.igem.org/Team:Lambert_GA/Hardware
RASHID, M. H., ASAEDA, T., & UDDIN, M. N. (2010). Litter-mediated allelopathic effects of kudzu ( Pueraria montana) on Bidens pilosa and Lolium perenne and its persistence in soil. Weed Biology & Management, 10(1), 48–56. https://doi.org/10.1111/j.1445-6664.2010.00366.x
NEWTON, C., NELSON, L., DEWALT, S., MIKHAILOVA, E., POST, C., SCHLAUTMAN, M., COX, S., BRIDGES, W., & HALL, K. (2008). Solarization for the control of Pueraria montana (kudzu). Weed Research, 48(5), 394–397. https://doi.org/10.1111/j.1365-3180.2008.00660.x