Extracellular nucleotides and apyrases regulate stomatal aperture in Arabidopsis.

This study investigates the role of extracellular nucleotides and apyrase enzymes in regulating stomatal aperture. Prior data indicate that the expression of two apyrases in Arabidopsis (Arabidopsis thaliana), APY1 and APY2, is strongly correlated with cell growth and secretory activity. Both are expressed strongly in guard cell protoplasts, as determined by reverse transcription-polymerase chain reaction and immunoblot analyses.