Cloning The Mads-box Family Genes In Rice (Oryza Sativa L.) And Molecular Identification, Preliminary Phenotype Analysis Of OsMADS6(Os1g18440) Transgenic Rice

MADS-box transcription factors are important transcription regulators ineukaryotic organism, play an important role in plant development and signaltransduction. MADS-box transcription factors have a highly conserved region knownas the MADS-box domain, which consists of56to58amino acids. Except for the AP2,all the ABCDE genes are MADS-box genes. MADS-box genes control diversedevelopment processes in flowering plants, ranging from vegetables development toflower and fruit development, especially control the processes of the transition fromvegetative to reproductive development and the establishment of floral organ identity.Given rice is one of the major crops in China, the study of MADS-box genes functionin rice floral organ has great theoretical significance and practical application prospecton improving the yield of crops.In this study the Japonica was used as the material. We cloned65MADs-boxgenes from all the tissues of rice. These cloned genes were constructed into theexpression vector VP64-pCambia1301and EAR-pCambia1301respectively. ByAgrobacterium-Mediated Genetic Transformation method, the vectors were transferedinto rice. Hygromycin resistant rice callus were selected. Totally we gained1218transgenic lines of38genes. We used hygromycin to select T1and T2MADS-boxtransgenic rice, and observed the T1generation in field. Then we found that VP64-OsMADS6, VP64-OsMADS7, VP64-OsMADS58and VP64-OsMADS74transgenicplants bloomed later compared with the wild-type. OsMADS6-5, OsMADS6-14，OsMADS6-31and OsMADS6-43transgenic plants showed not only flowering later butalso higher height and higher yield than that of wild-type. The Genomic DNA ofV-OsMADS6transgenic lines were extracted to detect the OsMADS6(Os1g18440)transgenic events. The PCR results and Western-blot results showed that this gene hasalready been integrated into rice genome and expressed correctly. The preliminarydata in our study suggests that OsMADS6may plays important role in rice photoperiodregulating in which OsMADS6delays the rice flowering. The extended vegetative growth stage increased the height of the OsMADS6transgenic plant.