Cloning And Sequence Analysis Of Wild Medicago Falcata Genes In Related To Environmental Stresses

Medicago falcata L. is a good kind of grazing of Leguminosae, it is possessed of cold, drought resistance and salt tolerance, rough grazing . It is important gene resources of plant resistibility breeding. China has rich Medicago falcata L. resources, so the study of excavation and use of its resistance gene resources has far-reaching significance to protect and innovate its breed quality resources. In this study, wild Medicago falcata L. was considered as material, Homology-based cloning was used to survey the gene cloning intimidated in adverse circumstances. The results described below:1. The third set of genes of LEA were get from Medicago falcata L. dealt with by use of cloning of RT-PCR, named MfLEA3-1 gene, its gene length is 747bp, a 744bp open reading frame is contained in it. It is supposed that it might encode 248 amino acids, which was made up of Thr(10.1%), Ala(24.6%), Lys(17.7%), Asp(12.9%) except for Cys and Trp. This is very similar to the LEA proteins component of other species. Otherwise, 13 11-mer repeat sequences were involved in this amino acid sequences. According to the classification standards of type I and type II of the third set of protein, the protein of MfLEA3-1 is closed to type I, but the residue distribution of 11-mer is different to that of type I. It is supposed that MfLEA3-1 protein belonged to the third set of LEA protein. The prediction results of secondary structure indicated that it was composed ofα-helix.2. A Proline synthase gene, named MfP5CS-1,was obtained from Medicago falcata L. done with NaCl using cloning and splicing of RT-PCR. The gene length is 1783bp, a 1596bp open reading frame is contained in it, and 531 amino acids are encoded by speculating. It contains four binding sites : ive nucleotide binding site,NAD(P) binding site,putative phosphate binding site,putative allosteric binding site, this gene has integrated conserved domains of PSCS gene and ALDH-SF of mammals and plants. The calculation results of its secondary structure showed that the secondary structure of MfP5CS-1 gene was made up ofα-helix mostly.3. RT-PCR and RACE were utilized to clone a cold induced gene from the Medicago falcata L. dealt with frozen, named MFCAS15B, its gene amino acid is most composed of Gly, a 10-peptide motif were repeated six times in gene sequence, the secondary structure is be composed of random coil .The analysis results of subcellular localization indicated that this gene located nucleus maximum-likelihood。...