Development of a Smell Biosensor System for Early Detection of Plant Diseases

Our goal is to use a smell biosensor system to predict the presence of pests and pathogens in an asymptomatic state by analysis of the complex fragrance mixture of agricultural, cultivated areas. For this purpose we utilized insect odorant receptors, some of which are extremely sensitive for certain biologically relevant volatile organic compounds (VOCs), and some are sensitive to a wide spectrum of fragrances.First, we collected air samples from the surroundings of healthy and diseased crop plants, and the samples were analyzed by gas chromatography linked to a mass spectrometer (GC-MS). We created Drosophila melanogaster Olfactory Receptor and calcium ion sensitive Fluorescent protein expressing (DromORF) stable cell lines as biosensors. By plating DromORF cells expressing different type of ORs to individual wells of 96 well plates, we recorded a digital "odor fingerprint" of several odorants and odorant mixtures in a fluorescent plate reader.Subsequently, we performed patch-clamp measurements on each DromORF cell line using most indicative components of plant VOC samples, to analyze VOC-evoked currents.Subsequently, we recorded VOC-evoked currents by whole-cell patch-clamp on each DromORF cell line using most indicative components of plant VOC samples.Odor identification was performed by neuronal networks, which combined fluorescent and electrophysiology readouts from DromORF cells with GC-MS results and literature data.Odor patterns were used to teach neuronal networks to recognize healthy and diseased status of plants.