Characterization And Expression Analysis Of OsGPRP Family Genes In Rice

Genes encoding glycine-and proline-rich protein(GPRP)are widely distributed in land plant,and have been confirmed to play an important role in plant growth and development as well as in response to adversity stress.However,until now there are few reports about theirs genetic structure,expression and function prediction in several land plants.Little is known about these genes in rice.In this study,three Os GPRP genes have been identified.By using bioinformatics,we have analyzed the genetic structure characteristics of the three Os GPRPs.Under normal and adverse circumstance,we have analyzed the expression patterns of the Os GPRPs in various rice tissues by using the fluorescence quantitative PCR.We also have primarly analyzed the subcellular location of Os GPRP by using the transient expression.In addition,we have primarly analyzed the prokaryotic expression of Os GPRP1 and Os GPRP3.Successfully building the overexpression vector of Os GPRP1 and Os GPRP2,and transforming into japonica rice Zhonghua 11 by using the agrobacterium-mediated method,we have obtained transgenic homozygous rice strain of Os GPRP1 and Os GPRP2.That lay a foundation for further researching the biological function of Os GPRPs.The main results were as follows:1.The structure characteristics analysis of the OsGPRPsThree OsGPRP genes have been identified by using bioinformatics.They have 2-3 exons and 1-2 introns with fixed occurring sites,and code 170-197 amino acids with molecular mass of 16.8-19.7k Da and isoelectric point of 7.53-9.82.And there are a variety of stress response elements in promoter region.Three typical and conserved regions(a XYPP-repeat domain,a hydrophobic domain rich in alanine and a HGK-repeat region)have been found in all these putative Os GPRP proteins by protein sequence structure analysis.It is high similarity of Os GPRP to other known plant GPRP proteins.Phylogenetic tree analysis results show that the Os GPRP1 and Os GPRP3 belong to the same branch,Os GPRP2 belongs to another branch.2.Under normal and abiotic stress conditions for the expression patterns of the Os GPRPs in various rice tissuesBy fluorescence quantitative PCR analysis,Three Os GPRP genes had differential expression patterns in rice seedlings roots,stems,leaves and panicles,and all of them had the highest gene expression quantity in the leaves.Under low temperature,drought and high salt stress processing,Os GPRP2 and Os GPRP3 were significantly higher expression in roots and stems,Os GPRP1 and Os GPRP2 were down-regulated expression in leaves;Under drought stress,Os GPRP1 gene was significantly up-regulated expressed in roots;Under salt stress,Os GPRP3 was significantly up-regulated expressed in leaves.3.Subcellular localization analysis of the Os GPRPWe observed and analyzed the transient expression of Os GPRP in tobacco leaves by using fluorescence microscope.The results show that Os GPRP1 and Os GPRP3 may locate in the nucleus and cytoplasm membrane,and Os GPRP2 may be mainly localization in the nucleus.4.Prokaryotic expression of OsGPRP1 and OsGPRP3We successfully built the prokaryotic expression vector of Os GPRP1 and Os GPRP3,and transformed into the E.coli BL21(DE3).We also successfully induced the proteins expression of Os GPRP1 and Os GPRP3.That can lay a foundation for exploring the Os GPRP properties.5.Overexpression vector construction,genetic transformation and identification of Os GPRP1 and Os GPRP2We successfully built the overexpression vector of Os GPRP1 and Os GPRP2,and transformed into japonica rice Zhonghua 11 by using the agrobacterium-mediated method.At present,one line for overexpressing transgenic homozygous rice strain of Os GPRP1 and Os GPRP2 have been screened respectively.That lay a foundation for further researching the biological function of Os GPRPs.