Abstract
ATP-binding cassette proteins are found in various organisms ranging from bacteria to human. It has been recently reported that their functions involve not only the efflux of xenobiotics but also various complicated physiological functions, such as regulation of other channels or functioning as molecular switch. P-glycoprotein (PGP)-like gene subfamily has drawn a large attention of many plant physiologists because some members are reportedly involved in auxin polar transport in plant body. In this study, we report the expression profile of AtPGP21 analyzed by northern blot and histochemical staining using Arabidopsis plants transformed with the AtPGP21 promoter::GUS fusion construct. These results showed that AtPGP21 was highly expressed both stem and roots, and revealed different response to plant hormones. We are establishing a heterologous expression system with Sf9 cells for the characterization of its biochemical functions.
