Description:
<jats:p>The <jats:italic>Arabidopsis</jats:italic> double pore K<jats:sup>+</jats:sup> channel KCO1 was fused to green fluorescent protein and expressed in tobacco protoplasts. Microscopic analysis revealed a bright green fluorescence at the vacuolar membrane. RT‐PCR experiments showed that KCO1 is expressed in the mesophyll. Vacuoles from <jats:italic>Arabidopsis</jats:italic> wild‐type and <jats:italic>kco1</jats:italic> knockout plants were isolated for patch‐clamp analyses. Currents mediated by slow‐activating vacuolar (SV) channels of mesophyll cell vacuoles were significantly smaller in <jats:italic>kco1</jats:italic> plants compared to the wild‐type. This shows that KCO1 is involved in the formation of SV channels.</jats:p>