title: Isolated plant nuclei as mechanical and thermal sensors involved in calcium signalling.
abstract: Calcium signals in the nucleus elicit downstream effects that are distinct from those of cytosolic calcium signals. In the present work, we have evaluated the ability of plant nuclei to sense stimuli directly and to convert them into calcium changes. We show that individual mechanical stimulation of isolated nuclei elicits a single calcium transient at acidic pHs, whereas a series of stimulations leads to oscillations whose frequency reflects that of the stimuli. Conversely, at alkaline pHs, nuclei respond to temperature but not to stretch. The stretch- and the temperature-activated processes differ by their sensitivity to pharmacological drugs known to affect ion channel activities in animal cells. Our data demonstrate that isolated nuclei are able to gauge physical parameters of their environment. This might have a profound influence on the functioning of calcium-dependent processes known to control a large array of molecular events in the nucleus.
authors.affiliation: UMR CNRS-UPS 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 17 Auzeville, 27 Chemin de Borde Rouge, 31326 Castanet-Tolosan, France.
authors.forename: Tou Cheu
authors.initials: TC
authors.lastname: Xiong
authors.forename: Alain
authors.initials: A
authors.lastname: Jauneau
authors.forename: Raoul
authors.initials: R
authors.lastname: Ranjeva
authors.forename: Christian
authors.initials: C
authors.lastname: Mazars
mesh_terms: D015374:Biosensing Techniques; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology* / Q000648:ultrastructure; D002469:Cell Separation; D011523:Protoplasts / Q000166:cytology / Q000502:physiology; D014026:Nicotiana / Q000166:cytology / Q000502:physiology*
chemical_list: D002118:Calcium