Abstract
OsPI1 (Oryza sativa Phosphate-limitation Inducible gene 1) cDNA, 375bp full-length, has been isolated from P-deficient rice roots using a cDNA microarray. The objective of this study was to analyze the function of OsPI1. P-deficiency resulted in OsPI1 mRNA being rapidly and systemically accumulated. The expression pattern corresponded with that of the novel P-deficient inducible genes designated as TPSI1/Mt4 family. The results of in situ hybridization of P-deficient rice indicated a higher accumulation of OsPI1 mRNA in young tissues, which require a larger amount of P. Sequence features and in vitro translation results indicated that OsPI1 is not the usual coding RNA, but has a specific function as the RNA molecule. We conclude that the OsPI1 gene has an important function in adaptation for P-deficiency that involves the regulation of other functional genes responding to P-deficient conditions. Preliminary results about the effect of OsPI1 knockout by RNAi will be presented.
