TY - JOUR T1 - Root electrotropism in <em>Arabidopsis</em> does not depend on auxin distribution, requires cytokinin biosynthesis and follows a power-law response curve JF - bioRxiv DO - 10.1101/2020.07.30.228379 SP - 2020.07.30.228379 AU - Nicholas Oliver AU - Maddalena Salvalaio AU - Deniz Tiknaz AU - Maximillian Schwarze AU - Nicolas Kral AU - Soo-Jeong Kim AU - Giovanni Sena Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/07/31/2020.07.30.228379.abstract N2 - An efficient foraging strategy for plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms range from sensing gravity (gravitropism), light (phototropism), water (hydrotropism), touch (thigmotropism) and more1. Electrotropism, also known as galvanotropism, is the phenomenon of aligning growth with external electric fields and currents2. Although observed in a few species3–5 since the end of the 19th century6, the molecular and physical mechanism of root electrotropism remains elusive, limiting the comparison to more defined sensing pathways in plants.Here we provide a first quantitative and molecular characterisation of root electrotropism in the model system Arabidopsis thaliana, showing that it does not depend on an asymmetric distribution of the plant hormone auxin, but that instead it requires the biosynthesis of a second hormone, cytokinin. We also show that the dose-response kinetics of root electrotropism follows a power law analogous to the one observed in common animal physiological reactions7, suggesting universal properties.A full molecular and quantitative characterisation of root electrotropism would represent a step forward towards a better understanding of signal integration in plants, and an independent outgroup for comparative analysis of electroreception in animals8 and fungi9.Competing Interest StatementThe authors have declared no competing interest. ER -