Abstract
Plants have various strategies to adapt to available phosphate amount from environment. One of the most important mechanisms is regulation of transporters. Plants change the kind and expression manner of transporter genes within a root. Therefore, seems to contain the different function in each part of the root for phosphate absorption. To understand the mechanisms we studied the real time absorption site and movement of phosphate in roots using radioactive tracer as well as a real time imaging system we developed. We supplied phosphate, 32P(PO43-), to the different part of the root, main root and side root of Arabidopsis thaliana. The amount of phosphate transferred from the main root to up ground part was about 2 times higher than that from the secondary root. When phosphate was supplied to the leaves, it was moved down to the roots within one hour. The result suggested that phosphate is moving in two orientations in a plant, up and down.
