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Characterization and Functional Analysis of Rice Outward Rectifier
Potassium Channels
Hyun Yeong Kim1, Eun-Hye Choi1, Hyunsik Hwang1, Jin-Ae Kim1, Beom-Gi Kim1,*
1
Department of Molecular Breeding Division, National Academy of Agricultural Science,
Rural Development Administration, Suwon, 441-707 Korea
Several shaker-like potassium channels was reported in rice. Among them two potassium
channels showed high similarities with Arabidopsis AtSKOR (stellar cell expressed outward
rectifying potassium channel) and AtGORK (guard cell expressed outward rectifying
potassium channel). Two potassium channels play important roles in guard cell movement and
potassium uploading. However, in monocot crops those genes were not studied well. In order
to identify functionally the two similar outward potassium channels in rice, we isolated the
promoter regions of the two genes and fused those to GUS reporter gene. The transgenic rice
expressing the GUS induced by two potassium channel promoter was stained by
histochemical method using X-Gluc. The expression patterns of those genes were quite
similar with Arabidopsis. One is expressed in guard cell and the other is expressed in the
vascular tissues. As the results those are named OsSKOR and OsGORK. In order to identify
the electrophysiological characteristics, we transiently expressed the genes in Chinese
hamster ovary (CHO) cells and we were recording the potassium currents using whole-cell
patch clamp method. These studies will contribute to understand the regulation of potassium
homeostasis and guard cell movement in monocot crop.
*Email: [email protected]