A role for the AKT1 potassium channel in plant nutrition

Science

Volumn 280, Issue 5365, 1998, Pages 918-921

  Hirsch, Rebecca E ^a   Lewis, Bryan D ^a   Spalding, Edgar P ^a   Sussman, Michael R ^a  

^a UNIVERSITY OF WISCONSIN MADISON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

MEMBRANE PROTEIN; POTASSIUM CHANNEL; POTASSIUM ION;

ARABIDOPSIS; ARTICLE; NONHUMAN; PLANT GROWTH; POTASSIUM TRANSPORT; PRIORITY JOURNAL;

NON-PROGRAMMATIC;

ARABIDOPSIS; ARABIDOPSIS PROTEINS; CULTURE MEDIA; DNA, BACTERIAL; GENES, PLANT; MEMBRANE POTENTIALS; MUTATION; PATCH-CLAMP TECHNIQUES; PLANT PROTEINS; PLANT ROOTS; POTASSIUM; POTASSIUM CHANNELS;

ARABIDOPSIS; ARABIDOPSIS THALIANA;

EID: 0032496329     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.280.5365.918     Document Type: Article

References (33)

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21. 2, 30 mM KCl, 5 mM Hepes, and 120 to 180 mM sorbitol (pH 7.0 with BTP). Protoplasts of nonepidermal cells emerged from the cut end of the otherwise undigested root. Patch pipettes were filled with 130 mM K-glutamate, 2 mM EGTA, 5 mM Hepes, and 4 mM Mg-adenosine triphosphate (Mg-ATP) (pH 7.0 with BTP). Patch-clamp equipment and procedures were as described [M. H. Cho and E. P. Spalding Proc. Natl. Acad. Sci. U.S.A. 93, 8134 (1996)]. Our procedures led to observations of inward currents in all patch-clamped wild-type cells. Lower percentages reported by others (5) may be explained by different growth conditions, different voltage protocols, or use of different tissue. We encountered more variability in the voltage dependence of the inward currents than has been reported for heterologously expressed inward rectifiers [F. Gaymard et al., J. Biol. Chem. 271, 22863 (1996)]. This variability is responsible for the appearance of weak rectification in the averaged whole-cell I-V curve in Fig. 3E. Channel gating may have been affected by cytoplasmic components that washed out in some patch-clamped protoplasts.
22. 2, 30 mM KCl, 5 mM Hepes, and 120 to 180 mM sorbitol (pH 7.0 with BTP). Protoplasts of nonepidermal cells emerged from the cut end of the otherwise undigested root. Patch pipettes were filled with 130 mM K-glutamate, 2 mM EGTA, 5 mM Hepes, and 4 mM Mg-adenosine triphosphate (Mg-ATP) (pH 7.0 with BTP). Patch-clamp equipment and procedures were as described [M. H. Cho and E. P. Spalding Proc. Natl. Acad. Sci. U.S.A. 93, 8134 (1996)]. Our procedures led to observations of inward currents in all patch-clamped wild-type cells. Lower percentages reported by others (5) may be explained by different growth conditions, different voltage protocols, or use of different tissue. We encountered more variability in the voltage dependence of the inward currents than has been reported for heterologously expressed inward rectifiers [F. Gaymard et al., J. Biol. Chem. 271, 22863 (1996)]. This variability is responsible for the appearance of weak rectification in the averaged whole-cell I-V curve in Fig. 3E. Channel gating may have been affected by cytoplasmic components that washed out in some patch-clamped protoplasts.
23. B. D. Lewis and E. P. Spalding, data not shown.
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33. Supported by the Department of Energy (DOE)/NSF/ USDA Collaborative Research in Plant Biology Program (BIR-9220331), funds to R.E.H. from the NIH University of Wisconsin Cellular and Molecular Biology Training Grant (GM07215), to M.R.S. from DOE (DE-FG02-88ER13938) and NSF (DCB-90-04068), and to E.P.S. from the NASA/NSF Network for Research on Plant Sensory Systems (IBN-9416016). We thank T. Janczewski and R. Meister for technical assistance and P. Krysan, W. Robertson, J. Satterlee, and J. Young for helpful comments on the manuscript.