The Varieties Screening Of Nitrogen Use Efficiency In Hordeum Vulgare And Bioinformatics Analysis Of GS Gene

Barley is important food crop in the world, but also nitrogen is important limiting factor affecting its growth, Nitrogen species breeding can not only reduce the waste of nitrogen ferterlization, but also improve the efficiency of utilization and get the more crop’s high and stable yield. And with the rapid development of transgenic technology and the study of the molecular mechanism of crop′s uptake and utilization to nitrogen, the use of genetic engineering to improve the efficiency of nitrogen utilization of crops have increasingly taken seriously. Glutamine synthetase(GS) plays an important role in nitrogen metabolism, it can convert inorganic nitrogen into organic nitrogen. Currently, GS gene of barley, corn, rice, Arabidopsis and other plants have been cloned, but GS bioinformatics is rarely reported. In addition, the terms of expression analysis are few involved in GS2. Therefore in this study, Starting from 48 barley materials, through controlled solution culture experiment, I analysised the correlation of relevant traits under seedling stage in low nitrogen, normal variation and high nitrogen conditions to filter out nitrogen efficiency and nitrogen inefficient barley varieties. Then I analysised the related bioinformatics and compared of four barley GS, and finally by q RT-PCR I did an expression analysis with the screened efficient and inefficient nitrogen barley varieties, laying the foundation for further study of the role of GS2 genes in the efficient use of nitrogen. Specific results are as follows:1. The analysis of barley variety screening about nitrogen use efficiency showed: The varieties′differences in biological traits of root, stem, leaf at barley seedling period under middle nitrogen is the most obvious. There is a porsertive certain correlation between dry weight and length traits under low nitrogen in various organs. Organ trait values of middle nitrogen and high nitrogen basically belong to nitrogen-efficient varieties greater than N inefficient varieties. Through evaluating the variation of seedling traits from 48 barley varieties, finaly, I selected a highly efficient nitrogen species, Z0099001, two nitrogen inefficient varieties, ARr-91 and Ganpi 7.2. The bioinformatics analysis of Hv GS gene family showed: The four proteins are all stable and hydrophilic proteins. Hv GS1-1 protein have a strong transmembrane helix in N-terminal, Hv GS1-2, Hv GS1-3 and Hv GS2 have no transmembrane proteins. GS homologous protein evolutionary analysis of 17 plant species showed, GS1 and GS2 protein in all kinds of plants are not clustered together, indicating that GS1 and GS2 genes appeared before the occurring of plant families and genera differentiation. In addition, The homology of GS gene in wheat, rye and barley is high, indicating that there is close genetic relationship between the three variaties.3. GS2 gene expression analysis showed: GS2 gene expression of nitrogen efficient species is greater than N inefficient species. In addition the expression of leaf> the expression of stem >the expression of roots; In the expression of stem under middle nitrogen, the species differences in nitrogen efficiency and inefficient varieties are the most obvious; The species differences in stems and leaves under high nitrogen are more obvious.