Highly reproducible periodic electrical potential changes associated with salt tolerance in wheat plants

Unlike animals, few vascular plants are known to spontaneously generate rhythmic electrical signals. In plants electrical signals triggered in response to external environmental changes are of physiological significance. However, plant electrical signals require experimental skill to measure, are stimulus-pattern dependent, and show poor quantitative reproducibility, thus their existence has been largely ignored by researchers. We developed a non-invasive and high-throughput light-induced in situ method to mine the information conveyed by reproducible bioelectrical activity in plants. Stable periodic electrical potential changes in wheat leaves induced by illumination darkness cycles enabled selection of wave features and specific classification algorithms were used to enable rapid distinction of salt-tolerant and salt-sensitive cultivars. Chlorophyll fluorescence data also strongly supported the association of rhythmic electrical potential with salt sensitivity in wheat leaves. The results show that the electrophysiological phenotype represented by plant rhythmic electrical potential is a novel candidate for phenotypic analyses. The method will also enable rapid assessment of the response and resistance to abiotic stresses of crop seedlings.