Expression of an Arabidopsis Potassium Channel Gene in Guard Cells

Abstract
The Arabidopsis thaliana KAT1 cDNA encodes a voltage-gated inward-rectifying K+ channel. A KAT1 genomic DNA clone was isolated and sequenced, and a 5[prime] promoter and coding sequences containing eight introns were identified. Reporter gene analysis of transgenic plants containing the KAT1 promoter fused to bacterial [beta]-glucuronidase showed robust [beta]-glucuronidase activity primarily in guard cells.