Abstract
Plants are able to perceive moisture gradients, the roots respond by growing towards water. This phenomenon is called hydrotropism. By using our HRS (Hydrotropism Research System) we isolated a mutant (cs2448) that does not exhibit the hydrotropic response. cs2448 plants lack the AKT2 gene, which encodes a voltage-gated K+ channel known to localize mainly in the phloem of aerial parts of Arabidopsis.
In this study ,we analyzed AKT2 expression in roots under dehydration stress, by using transgenic Arabidopsis plants expressing an AKT2 promoter::GUS fusion gene. GUS activity was detected at root tips; however, no activity was detected in root caps, which are regarded as the primary sites for hydrosensing. When akt2 plants were subjected to osmotic stress, root elongation was reduced compared to wild type. These results suggest that AKT2 plays a role in root elongation during dehydration stress. Further expression analysis of the AKT2 gene is now in progress.
