Magnetic Fields Impact on <scp>PIN</scp>‐<scp>FORMED</scp> Protein Polarity in <scp><i>Arabidopsis thaliana</i></scp>

Magnetic fields (MF) exert a considerable influence on biological processes in various organisms, including prominent effects on plant growth and development. Plant responses to MFs are highly diverse, implying that a plethora of processes are affected, hampering their molecular characterization. In this report, we employed the well-characterized plant model Arabidopsis thaliana to determine root growth responses to both static magnetic fields (SMF) and gradient magnetic fields (Gradient MF). SMF exposure resulted in a dosage-dependent inhibition of root elongation growth and altered auxin-responsive reporter expression, whilst Gradient MF exposure interfered with root curvature and auxin signaling under conditions of minimized gravity effects. Mutants deficient in components of the Arabidopsis auxin transport machinery were less responsive to MFs than wild type, indicative of MF-induced effects on polar auxin transport. When viewing the subcellular localization of PIN-FORMED (PIN) auxin efflux transporters in root meristems, we found that MFs impact their subcellular distribution in root cap and epidermis cells. These effects on PIN localization hint at a molecular switch, linking cellular protein dynamics, auxin transport, and morphogenesis, by which MFs impact the growth of higher plants.