We researched Osa-miR446 and its target gene APP1 on the basis of gene microarray. According to bioinformatics analysis, Osa-miR446 might have four target genes, but only LOC_Os03g56930.1 (named APP1) could be identified as one of target genes of Osa-miR446 via the RACE experiment. APP1 had an open reading frame of 711bp，encoding an undefined hydrophobicity protein with 237 amino acids. The Southern experiment showed that APP1 was a single-copy gene in rice genome. Expression profile under stressed of Osa-miR446 and APP1 was analyzed. Overall, the results indicated miR446 could regulate APP1 via splicing the transcriptions under stresses and they both played roles in stress response.
