Department of Physics, Chemistry and Biology (IFM)

The development of a protocol for isolation of root plastids from roots of Arabidopsis thaliana with high yields has been successful. In-vivo studies by radioactive phosphate transport experiments were possible with the help of knock out mutants. Results imply that transport of Pi via ANTR3 is dependent on a gradient either from proton concentration or cations (Na⁺). Back exchange experiments have aided us in establishing its activity in export and import of Pi. Last but not the least, phenotypic analysis have led to the observation of larger biomass in mutants leading to the conclusion that even though other transporters are present, the sink (roots) – source (leaves) balance is disturbed. So it can be concluded that Anion Transporter 3 has been localized to root plastid envelope membranes playing a pivotal role in Pi transport. It is a Na⁺ dependent transporter that can work either in the import or export of Pi according to their concentrations and environment.