Cloning And Functional Analysis Of Green Tissue-specific Expression Promoter Of Common Wild Rice (Oryza Rufipogon Griff.)

The growth and development of higher plants is the process of orderly and cooperative expression of different genes in time and space. The promoter, as an important regulatory element at the transcriptional level, binds to numerous transcription factors to determine the expression pattern and expression intensity of the gene. In-depth study of the structure, function and mode of the promoter is of great significance to reveal some of the basic theoretical problems in molecular biology.Molecular biology and genetic engineering methods used to study and improve the crop breeding in agriculture have broad prospects. The transgenic crops have commercialized more than 20 years since 1996 which has brought great economic benefits for the whole society. The expression of the exogenous gene in the transgenic crop is regulated by elements such as the promoter. It is required to clone some tissue-specific expression promoters, which make the exogenous gene express efficiently in a specific organ or tissue of the receptor crop.Common wild rice (Oryza rufipogon Griff.) is a close genetic ancestor of cultivated rice, which has abundant genetic diversity and is an important germplasm resource for the improvement of cultivated rice. In this study, four green tissue-specific expression genes were screened and identified on the basis of the common wild rice cDNA library, and the respective promoter sequences were cloned and named as OrGSPl, OrGSP2, OrGSP3 and OrGSP4. These promoters contain TATA-box, CAAT-box, light responsive element and hormone response element. The GUS gene expression vectors of every green tissue-specific promoter were constructed. Nicotiana tabacum transient transformation shows that these promoters have the activity of expression. We got T2 transgenic Arabidopsis thaliana plants by Agrobacterium-mediated dipping method. GUS histochemical assay demonstrates that these promoters are green tissue-specific expression promoters. The GUS enzyme activity shows that its activity in the green tissue increases significantly than in root at seedling stage and maturity stage by standard curve method.