Complex electrical signatures of Maize and Brachypodium primary roots

We investigated the frequency-dependent electrical properties in terms of conduction and polarization of single root segments of Brachypodium (Brachypodium distachyon L.) and Maize (Zea mays L.). First we designed a sample holder to investigate the electrical properties of root segments and tested it on ideal resistors. We found that it is suitable to assess the electrical properties of crop root segments of 1-5 cm length in a frequency range between 1 Hz and 45 kHz. The system was then used to obtain the complex electrical response of Brachypodium and Maize root segments at 10 different ages, from 8-29 days after sowing (DAS). It was found that the electrical properties of the root segments varied with age and species. This variation was linked to root anatomy based on the microscopic analysis of root sections.