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KAT1 is not essential for stomatal opening.

ABSTRACT: It is generally accepted that K(+) uptake into guard cells via inward-rectifying K(+) channels is required for stomatal opening. To test whether the guard cell K(+) channel KAT1 is essential for stomatal opening, a knockout mutant, KAT1En-1, was isolated from an En-1 mutagenized Arabidopsis thaliana population. Stomatal action and K(+) uptake, however, were not impaired in KAT1-deficient plants. Reverse transcription-PCR experiments with isolated guard cell protoplasts showed that in addition to KAT1, the K(+) channels AKT1, AKT2/3, AtKC1, and KAT2 were expressed in this cell type. In impalement measurements, intact guard cells exhibited inward-rectifying K(+) currents across the plasma membrane of both wild-type and KAT1En-1 plants. This study demonstrates that multiple K(+) channel transcripts exist in guard cells and that KAT1 is not essential for stomatal action.

SUBMITTER: Szyroki A

PROVIDER: S-EPMC30240 | biostudies-literature | 2001 Feb

REPOSITORIES: biostudies-literature

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KAT1 is not essential for stomatal opening.

Szyroki A A Ivashikina N N Dietrich P P Roelfsema M R MR Ache P P Reintanz B B Deeken R R Godde M M Felle H H Steinmeyer R R Palme K K Hedrich R R

Proceedings of the National Academy of Sciences of the United States of America 20010220 5

It is generally accepted that K(+) uptake into guard cells via inward-rectifying K(+) channels is required for stomatal opening. To test whether the guard cell K(+) channel KAT1 is essential for stomatal opening, a knockout mutant, KAT1En-1, was isolated from an En-1 mutagenized Arabidopsis thaliana population. Stomatal action and K(+) uptake, however, were not impaired in KAT1-deficient plants. Reverse transcription-PCR experiments with isolated guard cell protoplasts showed that in addition to ...[more]

PMID: 11226341

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