Bioinformatics Analysis And Identification Of CLE Peptide Gene Family Of Model Plants

CLE(CLAVATA3/Embryo surrounding region-related) polypeptide hormone is the plant polypeptide hormone that we care most in recent ten years and the largest plant peptide family so far, involving in signal transduction between cells by coding a group of small secretory peptides, so as to control the balance between stem cell proliferation and differentiation during the plant growth and development process. It also plays a key role in regulating the development of plant tissues, especially in shoot apical meristem(SAM), root apical meristem(RAM) and procambium. Despite the existing research of CLE gene family in several model plants, like Arabidopsis thaliana and Oryza sativa, little is known about CLE polypeptide gene family in the model plant of xylophyta like poplar and the model plant of sarcocarp plant like tomato.With the model plants, poplar and tomato, as the research object, this study uses all of the 32 CLE genes of Arabidopsis thaliana for gene retrieval and mining in the phytozome v10.1 database, getting 50 poplar CLE candidate genes(Pt CLE) and 15 tomato CLE candidate genes(SlCLE) in the end. Then using bioinformatics methods, the CLE genes of poplar and tomato are conducted with physical and chemical properties analysis, prediction of signal peptide, gene structure analysis, chromosome location, multiple sequence alignment, the construction of phylogenetic tree based on the protein sequence and CLE 12 peptide, the search of the upstream regulation area cis-acting element, as well as the drawing of expression heat map, etc. In the poplar, it picks out three poplar CLE genes being homologous with At CLV3 and six poplar CLE genes being homologous with At CLE41/44 to construct the expression vectors for the nine Pt CLE genes, verifying the expression of its tissue specificity with the use of real-time quantitative PCR technique. As to the tomato, it verifies the expression of the tissue specificity of all the 15 tomato CLE genes, and picks out three specific expression genes: SlCLE10, 12 and 13.After the synthetic of the CLE 12 peptide of the above three SlCLE genes, then deal with tomato seedlings by adding the polypeptide in vitro method, it finds that the three 12-peptide are able to inhibit the elongation of tomato main root, and SlCLE12 has the most significant inhibitory effect, also there is plenty of anthocyanin accumulated in the hypocotyl part.By using the methods of bioinformatics and comparative genomics, etc., this article makes identification and analysis of CLE gene family in the two model plants of poplar and tomato for the first time, and it is the important supplement for the research of plant signal transduction process. Meanwhile, it also provides an important theoretical basis for the study on the formation and development of vascular tissue in model plant of xylophyta, as well as the study on the development and ripening of fruit in model plant of sarcocarp.