Bioinformatic Studies Of Pant Defensin And Gene Cloning Of Vitis Vinifera Defensin

Content: Based on the Public databases, using the theories and methods of bioinformatics, take the plant defensin as the example, to carry out prediction and sequence analysis. Simultaneously, to conduct various research of the predicted Vitis vinifera defensins and according to this, clone the defensins successfully. It provides the advantage for its following function research and the large scale production and at the same time, provides new methods to research of the other gene families . The main results of this study were demonstrated as follows:(1) With defined 9 plant defensins as references, we search 28 plant species database in the DFCI by BLAST and ORF finder to find the homologous sequences. We find 115 new plant defensin genes in 24 species. The results of signal P, mature peptide sequences alignment and phylogenetic analysis using NJ methods indicated that many of them have the signal peptide sequence, all of them have the same conservative sequence with plant defensin and may divide into two kinds. It shows that all the 115 defensin genes show high homology and with the basic characteristics of plant defensin.(2) By the bioinformatic methods and tools, 4 plant defensin genes as well as the composition of amion and sequences, post-translational modification, signal P, hydrophobicity or hydrophilicity, transmembrane ability, secondary structure and functional domains of Vitis vinifera.The results demonstrate that three of them are secretory proteins containing signal peptide, the other one has no signal peptide and the main motifs of predicted secondary structure of them are alpha helix and random coil, bate turn and extended strand are spreaded in the whole secondary structure. All of them contain functional domains-gamma-thionin.(3) Phylogenetic analysis of the predicted the 4 defensins of Vitis vinifera with the identified defensins of Arabidopsis thaliana, it shows that the 4 predicted defensins have high homology with the second family of Arabidopsis thaliana defensin. The genomic information of the 4 predicted defensins shows that 3 defensins which have signal peptide sequence also have a intron which have a low homology with the second family of Arabidopsis thaliana defensin. The expression profile shows that, they may expression in many organs. (4) The functional elements of the 2 defensins of Vitis vinifera promoters were analysed by PlantCARE programm. Both of them contain the basic elements: TATA-box, CAAT-box, the fungal elicitor responsive element - Box-W1 and cis-acting element involved in defense and stress responsiveness - TC-rich repeats.One of them has one auxin-responsive element-TGA-element, one cis-acting element involved in the abscisic acid responsiveness-ABRE, two cis-acting regulatory element involved in the MeJA-responsiveness - CGTCA-motif and TGACG-motif.(5) According to the bioinformatics prediction and analysis, successfully cloned three defensin genes of Vitis vinifera.