Abstract
Cation diffusion facilitator (CDF) family is thought to implicate in the metal tolerance mechanisms of a range of organisms. ZAT (zinc transporter of Arabidopsis thaliana) belongs to the CDF family, and the over-expressed Arabidopsis plant was reported to be strengthened zinc tolerance by internal sequestration. However, its subcellular localization is unclear. We investigated the localization of ZAT by immunological study using a ZAT specific antibody. Western blotting using sucrose density fractionated microsome and chloroplast fraction showed that 58 kDa ZAT protein was localized to the chloroplast envelope membrane. ZAT protein was detected in greenish organs but not in roots, seeds and etiolated seedlings as well as the RuBisCO large subunit and the amount of chlorophyll. Immunofluorescence staining of ZAT protein against the leaf section also showed the chloroplast localization. We will discuss the physiological function of ZAT
