Abstract:OsPIN1a and OsPIN1b of auxin efflux carrier OsPIN1 family genes were demonstrated in regulating negative phototropism of rice roots. To study relationship between OsPIN1d and negative phototropism of rice roots, we amplified the complete open reading frame of OsPIN1d through reverse transcriptasepolymerase chain reaction (RTPCR) based on sequence deposited in GenBank (Accession number: BR000830). Bioinformatics analysis showed that OsPIN1d was consisted of 1 497 bp, coding 554 amino acids (AA), and GC content was 64.08%. AA sequence comparison and phylogenic tree indicated that OsPIN1d gene belongs to plant PINs, which is closed to OsPIN1b in rice, OsPIN4 in maize, AtPIN2, OsPIN1c, OsPIN1a and AtPIN1 in Arabidopsis. Fusion expression vector pCAMBIA1301OsPIN1d∷GFP containing OsPIN1d gene was constructed to obtain T2 generation transgenic rice. RTPCR molecular detection and βglucuronidase staining showed that the target construct was integrated into genome of rice, mainly locating in root. Irradiated with unilateral light, the negative phototropic curvatures of transgenic rice seed roots were higher than those of wild type. Moreover, OsPIN1dGFP in shaded side was significantly higher than that in irradiated side in elongation zone of transgenic rice root tip. It was indicated that OsPIN1d is involved in transportation of IAA and NAA, thus promoting formation of negative phototropism in rice roots.