Electrochemical monitoring of ROS influence on seedlings and germination response to salinity stress of three species of the tribe Inuleae

Solid-state electrochemical methods have been applied to the establishment of patterns of plant growth and response to saline stress using seedlings of Inula helenium L., Dittrichia viscosa (L.) Greuter (Inula viscosa (L.) Aiton), Limbarda crithmoides (L.) Dumort (Inula crithmoides L.). Upon in situ electrochemical generation of reactive oxygen species (ROS) the reactivity with such species was monitored using voltammetric signals associated to the oxidation of polyphenolic components of the plants. A simple kinetic model based on second-order reaction between ROS and polyphenolic components is applied to electrochemical data yielding apparent rate constants which can be correlated with the level of saline stress revealing significant differences between the tested species. These results were contrasted with the seed germination response to salt concentration in order to check potentiality of voltammetric techniques as analytical tools for evaluating salt stress tolerance in plants.