SLAC1 is required for plant guard cell S-type anion channel function in stomatal signalling

Triin Vahisalu, Hannes Kollist, Yong-Fei Wang, Noriyuki Nishimura, Wai-Yin Chan, Gabriel Valerio, Airi Lamminmäki, Mikael Brosche, Heino Moldau, Radhika Desikan, Julian I Schroeder, Jaakko Kangasjärvi

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

Abstrakti

Stomatal pores, formed by two surrounding guard cells in the epidermis of plant leaves, allow influx of atmospheric carbon dioxide in exchange for transpirational water loss. Stomata also restrict the entry of ozone - an important air pollutant that has an increasingly negative impact on crop yields, and thus global carbon fixation(1) and climate change(2). The aperture of stomatal pores is regulated by the transport of osmotically active ions and metabolites across guard cell membranes(3,4). Despite the vital role of guard cells in controlling plant water loss(3,4), ozone sensitivity(1,2) and CO2 supply(2,5-7), the genes encoding some of the main regulators of stomatal movements remain unknown. It has been proposed that guard cell anion channels function as important regulators of stomatal closure and are essential in mediating stomatal responses to physiological and stress stimuli(3,4,8). However, the genes encoding membrane proteins that mediate guard cell anion efflux have not yet been identified. Here we report the mapping and characterization of an ozone- sensitive Arabidopsis thaliana mutant, slac1. We show that SLAC1 ( SLOW ANION CHANNEL- ASSOCIATED 1) is preferentially expressed in guard cells and encodes a distant homologue of fungal and bacterial dicarboxylate/ malic acid transport proteins. The plasma membrane protein SLAC1 is essential for stomatal closure in response to CO2, abscisic acid, ozone, light/ dark transitions, humidity change, calcium ions, hydrogen peroxide and nitric oxide. Mutations in SLAC1 impair slow ( S- type) anion channel currents that are activated by cytosolic Ca2(+) and abscisic acid, but do not affect rapid ( R- type) anion channel currents or Ca2+ channel function. A low homology of SLAC1 to bacterial and fungal organic acid transport proteins, and the permeability of S- type anion channels to malate(9) suggest a vital role for SLAC1 in the function of S- type anion channels.
Alkuperäiskielienglanti
LehtiNature
Vuosikerta452
Numero7186
Sivut487-491
Sivumäärä5
ISSN0028-0836
DOI - pysyväislinkit
TilaJulkaistu - 2008
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

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  • 311 Peruslääketieteet
  • 318 Lääketieteen bioteknologia
  • 411 Maatalous ja metsätieteet
  • 118 Biotieteet
  • 219 Ympäristön bioteknologia
  • 519 Yhteiskuntamaantiede, talousmaantiede

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