Preliminry Functional Analysis Of The Gebp Gene Family In Rice

GeBP (Glabrous-enhancer binding protein) is a plant-specific transcription factor family, specially recognizes and binds with the GL1(Glabrousl) enhancer. It is vital for leaf development and trichome initiation.To explore the functions of OsGeBP, bioinformatics analysis of OsGeBP family genes was carried out; relative expression levels of members of this gene family under hormone treatements with different concentrations were carried out; phenotypes, genotyping and expression levels of OsGeBP mutants were identified; OsGeBP over-expression and amiRNA vectors were constructed and were transformed into rice. Seedlings with the insertion of the transgenes were obtained.The main results are as follows:1. Bioinformatics analysis revealed fifteen GL1-enhancer binding proteins in rice, named as OsGeBPl-15. Phylogenetic tree were constructed using fifteen OsGeBP and twenty-one AtGeBP genes. By analyzing the chromosomal distribution of the OsGeBP genes, we found that they were distributed on chromosomes1,2,3,6,7,8and9. Analysis of the gene structure of the fifteen OsGeBP genes shows that only OsGeBP10and OsGeBP12contain introns. Expression pattern analysis of twelve OsGeBP genes were performed, using data from microarrays in different databases. Induced expression profiles indicated that OsGeBP genes co-express with hormone responsive and lignin biosynthesis genes, suggesting their involvement in stress response. A number of putative cis-elements were found in the1.5kb upstream region of fifteen OsGeBP genes, such as ARR1AT, CAATBOX1, CACTFTPPCA1, Dofcorezm, POLLEN1LELAT52, which are related to CK response, senescence, anther and pollen development. Subcellular location prediction showed that members of the family were differently located, such as thylakoid membrane, nucleus and cytoplasm.2. The relative expression levels of members of this gene family under hormone treatements (GA, ABA, BR, KT and ACC) with different concentrations were carried out and the result showed OsGeBP8expression were induced by all the hormonal treatments, especially under BR and ACC treatments.3. We observed phenotypes of Osgebp3, Osgebp4, Osgebp7, Osgebp8, Osgebpll, Osgebpl4under normal growth. Osgebp3, Osgebp7, Osgebp8show overall slower germination than wild type (WT) seeds; from the root, Osgebp3with less root hair, thinner root, less lateral root. Osgebp7with white lateral root, Osgebp8with white taproot but lateral root, Osgebpll has less root hair and one without lateral root; Osgebpl4with longer root hair. Two tillering stage in hydroponicsaverage of longest root length statistics, Osgebp3, Osgebp7, Osgebp8, Osgebpll with shorter root, Osgebp4and Osgebpl4identical to the WT. Ripening stage in experimental field:Osgebp3, Osgebp4, Osgebp7, Osgebp8with dwarf.Osgebp3with thinner stem; Osgebp8with avocado curlved leafs, plexiform and infertility plants, identical to classical BR-deficient phenotypes; Osgebpll with fragile leaf, leaf sheath and stem; Osgebp7with semi-dwarf plants. Particularly, the heights of the plants are positively related to its expression in Osgebp7.4. Eleven OsGeBP over-expression and two OsGeBP amiRNA vectors were constructed and were transformed into rice (Zhonghuall variety). Seedlings with the insertion of the transgenes were obtained.Predictions and preliminary exploration of rice OsGeBP transcription factors have created valuable materials, which make it posible to further study the functions of this family.