PLANT-Dx: A Molecular Diagnostic for Point of Use Detection of Plant Pathogens

M. Verosloff; J. Chappell; K. L. Perry; J. R. Thompson; J. B. Lucks

To address these shortcomings, we sought to develop a PoUD system called PLANT-Dx (Point of use LAboratory for Nucleic acids in a Tube) that combines the sensitivity of isothermal strategies to amplify target plant pathogen nucleic acids (10) , with the designability of synthetic gene regulatory systems (11) and robustness of cell free gene expression reactions (12) to produce colorimetric outputs that are visible to the naked-eye ( Figure 1A) . The overall approach of our PLANT-Dx system is to convert plant pathogen nucleic acids into constructs encoding designed synthetic RNA regulators that when produced activate an RNA genetic switch controlling the expression of an enzyme that catalyzes a color change. The RNA genetic switch thus serves a role as a signal processing layer that filters the noisy output of isothermal amplification products (10) , only triggering the production of color for correctly amplified ontarget viral sequences.