Nitric oxide production in tobacco leaf cells: a generalized stress response?

Authors

  • K. S. GOULD,

    Corresponding author
    1. Plant Sciences Group, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand and
    Search for more papers by this author
  • O. LAMOTTE,

    1. UMR 1088 INRA/Université de Bourgogne et FRE/CNRS 2625, Plante-Microbe-Environnement, INRA, 17 rue Sully, BP 86510, Dijon 21065 cedex, France
    Search for more papers by this author
  • A. KLINGUER,

    1. UMR 1088 INRA/Université de Bourgogne et FRE/CNRS 2625, Plante-Microbe-Environnement, INRA, 17 rue Sully, BP 86510, Dijon 21065 cedex, France
    Search for more papers by this author
  • A. PUGIN,

    1. UMR 1088 INRA/Université de Bourgogne et FRE/CNRS 2625, Plante-Microbe-Environnement, INRA, 17 rue Sully, BP 86510, Dijon 21065 cedex, France
    Search for more papers by this author
  • D. WENDEHENNE

    1. UMR 1088 INRA/Université de Bourgogne et FRE/CNRS 2625, Plante-Microbe-Environnement, INRA, 17 rue Sully, BP 86510, Dijon 21065 cedex, France
    Search for more papers by this author

Kevin S. Gould. E-mail: k.gould@auckland.ac.nz

ABSTRACT

The function of nitric oxide (NO), a gaseous free radical emitted by many plants, is incompletely understood. In the present study the hypothesis that NO generation, like that of the reactive oxygen species, occurs as a general response to different environmental cues was tested. Leaf peels and mesophyll cell suspensions of Nicotiana tabacum cv. Xanthi were loaded with the NO-specific fluorophore, diaminofluorescein, and subjected to an abiotic stressor. Light stress and mechanical injury had no apparent effect on NO production. In contrast, high temperatures, hyperosmotic stress, salinity and epi-illumination in a microscope all led to rapid surges in NO-induced fluorescence. The fluorescence originated from cells of the palisade mesophyll and across all epidermal cell types, including guard cells, subsidiary cells, and long and short trichomes. Fluorescence was evident first in the plastids, then in the nucleus and finally throughout the cytosol. Nicotiana plumbaginifolia cell suspensions expressing the calcium reporter aequorin provided evidence that, under hyperosmotic stress, NO participates in the elevation of free Ca2+ in the cytoplasm. The physiological significance of NO production in response to abiotic stressors is discussed.

Ancillary