The complete open reading frame of OsPINla was amplified through reverse transcriptase- polymerase chain reaction （RT-PCR） based on the sequence deposited in GenBank to explore the relationship between the auxin efflux protein OsPINla and the negative phototropism of rice roots. Sequencing results showed that the GC content of OsPINla was 65.49%. The fusion expression vector pCAMBIA-1301-OsP/N1a：：GFP containing the OsPINla gene and a coding green fluorescent protein （gfp） gene was constructed. The fusion vector was transferred into onion epidermal cells by Agrobacterium tumefaciens transformation. The transient expression of OsPINla-GFP was mainly located in the nucleus and cell membrane. Moreover, the transgenic plants were obtained by Agrobacterium-mediated genetic transformation. Molecular detection performed by using PCR and β-glucuronidase staining showed that the target construct was integrated into the genome of rice. The negative phototropic curvatures of the transgenic rice roots were higher than those of the wild type. Similarly, the expression levels of OsPINla in the transgenic plants were considerably higher than those in the wild-type plants. These results suggest that OsPINla is crucial in the negative phototropic curvature of rice roots.
