KDC2, a functional homomeric potassium channel expressed during carrot embryogenesis

In Daucus carota, the model system for embryogenesis, it has been demonstrated that potassium and K(+) selective channels are involved in embryo development. Here, we report the isolation and cloning of a new carrot Shaker-like potassium channel, potassium D. carota channel 2 (KDC2), whose expression pattern during somatic embryogenesis proceeds along with the establishment of the polar axes and the settlement of the hypocotyl region. In plants, KDC2 transcript is localized at the shoot level, in the epidermis and guard cells, similarly to its Arabidopsis homolog KAT1. Electrophysiological assays indicated KDC2 as the first carrot subunit able to form homomeric functional channels in Xenopus oocytes, with properties similar to those of Arabidopsis KAT1.