Objective  Functions of a peptide transporter protein gene, OsPtr1, in rice were studied by means of T-DNA insertion mutation.

  Method   The target RNA was extracted from the endosperm of Minghui 86 rice 12 d after flowering and reverse-transcribed into cDNA. By cloning the candidate gene P0421H01.23, named OsPtr1, and constructing the plant overexpression vector using the promoter Gt1 of endosperm-specific expressing, OsPtr1 was introduced into Nipponbare rice using an agrobacterium-mediated method. Nitrogen metabolism of the offspring and mutant w9101 was analyzed. A fusion expression vector of green fluorescent protein gene, GFP, and OsPtr1 was constructed and transferred to onion epidermal cells with a gene gun. In 24–48 h afterward, subcellular localization of OsPtr1 was examined under a fluorescence confocal electron microscope.

  Result  OsPtr1 was localized at the membrane and possibly involved in the transport of nitrogen substances. Knockout on OsPtr1 could cause a reduction on nitrogen-containing substances, such as amino acids and proteins, in the rice grains. Conversely, an overexpressed OsPtr1 would increase the accumulation.

  Conclusion   OsPtr1 participated in the transmembrane transport of nitrogen substances in rice.