Stretched by Stress: PIEZO1 is a mechanosensitive ion channel in Arabidopsis (PNAS)

Plants are constantly susceptible to mechanical stress and they have evolved intracellular signaling mechanisms to adapt to mechanical stimulation. Whilst it is known that ion channels activate signaling pathways in response to mechanical stress, only few of these mechanosensitive channels have been identified in plants. Here, Mousavi and colleagues characterized PIEZO1 (PZO1), a member of a family of ion channels that are well known in transducing mechanical signals in animals, as a mechanosensitive channel in Arabidopsis thaliana. The authors found the protein expression to be abundant in the roots, especially around the root cap that experiences high mechanical pressure when growing into the substratum. Roots of seedlings mutated in PZO1 were unable to grow inside solid agar medium. Using electrophysiological and calcium (Ca²⁺) imaging experiments, the authors showed that PZO1 is a non-selective cation channel that mediates currents in response to mechanical stimulus and is required for mechanical stress-induced Ca²⁺ signaling. This study is thus an important contribution in understanding mechanosensing in plants and the conserved function of PZO channel family in plants and animals. (Summary by Pavithran Narayanan @pavi_narayanan). PNAS. 10.1073/pnas.2102188118