(134b) The Role of Basal H2O2 Concentration in ROS Stress Signaling Waveforms in Planta

In response to stress, living plants propagate a chemical wave comprised of H₂O₂ through their tissues. Advances in nanosensors capable of measuring H₂O₂ within the living plant in real time have informed a quantitative theory to describe the spatiotemporal profile of its concentration, labeled a signaling waveform. A heretofore unaddressed aspect of the theory is the role of existing basal H₂O₂ level within the plant before and after stress wave propagation, potentially informing mechanisms of stress priming, or state changes associated with prior, low magnitude levels of stress, that condition the resulting waveform. Herein, we develop a mathematical description of wave propagation within an existing basal level of H₂O₂. The shape and intensity of the waveform is decoupled from basal H₂O₂. This equilibrium concentration can then operate as a distinct, orthogonal signaling channel within the plant, distinguishing the information within the waveform resulting from the stress event, from priming conditions. The theory described herein should have utility in analyzing stress signaling within living plants and form the basis of differentiating stress and priming conditions.

Keywords: Stress Signaling, Plants, Reactive Oxygen Species, Reaction and Diffusion, Stress Priming