Abstract
It is proposed that P-deficiency inducible gene is regulated by the long-distance signaling from shoots, because these are repressed by high status of shoot P though low P concentration around roots. However regulation mechanisms of P-deficiency inducible gene expression is not detailed. We have isolated a P-limitation inducible novel rice gene OsPI1. The aim of this study is to investigate expression pattern of OsPI1. P re-supply and split-root experiments were conducted using P-deficient rice plants. Roots and shoots were collected continuously, and then P-status and accumulation of OsPI1 transcripts were analyzed. In re-supply treatment, P was absorbed and OsPI1 was repressed immediately. P was increased in +P split-roots and shoot, and OsPI1 was repressed. In -P split-roots, significant changes of P-status and OsPI1 accumulation were not found during 12h. It is indicated that OsPI1 is regulated not only by the long-distance signaling, but also by the local P-status in roots.
