P.L.A.N.T. Plant-based Ligand Activated Noxious agent Tracker - make the invisible visible
HydrocultureWe decided to detect several chemicals using our system, namely methylphosphonic acid (MPA), diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP), thiodiglycol (TDG) and benzenetricarboxylic acid (BTCA). These chemicals, related to chemical weapons but safe to work with, are stable in nature and have the potential to severely contaminate the environment and groundwater. For our plant-based detection system of these chemicals, it is important to test if they are absorbed by plants and therefore are detectable. We cultivated Nicotiana benthamiana as hydroculture and demonstrated that the plants tolerate DIMP, DEMP, MPA and TDG in different concentrations. Furthermore, we showed the up take of said chemicals into the plant.
Protein EngineeringCrucial for the functionality of our detection system for degradation products of chemical weapons is a receptor which is able to bind the targeted chemical. By applying computational protein design on a ribose binding protein, we created a functional and specific receptor to bind a weapon related chemical. By using a modular system, the receptor can be changed easily to create a customized plant for detection of specific chemicals. One way to do this is the computational design we performed (Parts: BBa_K3900001, BBa_K3900002, BBa_K3900003, BBa_K3900004, BBa_K3900005, BBa_K3900006).
Reporter Ruby & AnthosAfter detection of a chemical weapon degradation product and the activation of the signaling cascade, a visible output is created. Therefore, we introduce the RUBY reporter (BBa_K3900028), which comprises genes for betalain biosynthesis. Expression of this reporter results in a visible red coloration of the plant.
Bacterial and plant test systemsOur plant-system allows the detection of specific chemicals based on a signal cascade activated by a receptor that specifically binds ligands. To perform initial tests with our signaling cascade and our newly engineered receptors, another fast growing and easy manipulative model organism was required. Therefore, we worked with Escherichia coli for first testing of a bacteria adapted signaling cascade and the engineered receptors. To demonstrate its functionality, we tested the plant signaling cascade by transient expression in Nicotiana benthamiana (Parts: BBa_K206000, BBa_K216004, BBa_B0014, BBa_K216003, BBa_K808000, BBa_R0082, BBa_E0040, BBa_P1003, BBa_K731722).