Dominant negative guard cell K+ channel mutants reduce inward-rectifying K+ currents and light-induced stomatal opening in arabidopsis

J. M. Kwak, Yoshiyuki Murata, V. M. Baizabal-Aguirre, J. Merrill, M. Wang, A. Kemper, S. D. Hawke, G. Tallman, J. I. Schroeder

Research output: Contribution to journalArticle

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Abstract

Inward-rectifying potassium (K+in) channels in guard cells have been suggested to provide a pathway for K+ uptake into guard cells during stomatal opening. To test the proposed role of guard cell K+in channels in light-induced stomatal opening, transgenic Arabidopsis plants were generated that expressed dominant negative point mutations in the K+in channel subunit KAT1. Patch-clamp analyses with transgenic guard cells from independent lines showed that K+in current magnitudes were reduced by approximately 75% compared with vector-transformed controls at -180 mV, which resulted in reduction in light-induced stomatal opening by 38% to 45% compared with vector-transformed controls. Analyses of intracellular K+ content using both sodium hexanitrocobaltate (III) and elemental x-ray microanalyses showed that light-induced K+ uptake was also significantly reduced in guard cells of K+in channel depressor lines. These findings support the model that K+in channels contribute to K+ uptake during light-induced stomatal opening. Furthermore, transpirational water loss from leaves was reduced in the K+in channel depressor lines. Comparisons of guard cell K+in current magnitudes among four different transgenic lines with different K+in current magnitudes show the range of activities of K+in channels required for guard cell K+ uptake during light-induced stomatal opening.

Original languageEnglish
Pages (from-to)473-485
Number of pages13
JournalPlant Physiology
Volume127
Issue number2
DOIs
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

potassium channels
guard cells
Arabidopsis
Light
mutants
vector control
genetically modified organisms
Genetically Modified Plants
Point Mutation
point mutation
Potassium
Sodium
X-Rays
X-radiation
Cell Line
potassium
sodium
Water
leaves

ASJC Scopus subject areas

  • Plant Science

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Dominant negative guard cell K+ channel mutants reduce inward-rectifying K+ currents and light-induced stomatal opening in arabidopsis. / Kwak, J. M.; Murata, Yoshiyuki; Baizabal-Aguirre, V. M.; Merrill, J.; Wang, M.; Kemper, A.; Hawke, S. D.; Tallman, G.; Schroeder, J. I.

In: Plant Physiology, Vol. 127, No. 2, 2001, p. 473-485.

Research output: Contribution to journalArticle

Kwak, JM, Murata, Y, Baizabal-Aguirre, VM, Merrill, J, Wang, M, Kemper, A, Hawke, SD, Tallman, G & Schroeder, JI 2001, 'Dominant negative guard cell K+ channel mutants reduce inward-rectifying K+ currents and light-induced stomatal opening in arabidopsis', Plant Physiology, vol. 127, no. 2, pp. 473-485. https://doi.org/10.1104/pp.127.2.473
Kwak, J. M. ; Murata, Yoshiyuki ; Baizabal-Aguirre, V. M. ; Merrill, J. ; Wang, M. ; Kemper, A. ; Hawke, S. D. ; Tallman, G. ; Schroeder, J. I. / Dominant negative guard cell K+ channel mutants reduce inward-rectifying K+ currents and light-induced stomatal opening in arabidopsis. In: Plant Physiology. 2001 ; Vol. 127, No. 2. pp. 473-485.
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