Expression And Evolution Analysis Of BCCP Family From Glycine Max And CHI Family From Arachis Hypogaea

The existence of gene family has great significance to plant evolution. Multiplecopies of gene could provide more adaptation opportunities and lower purifyingselection pressure. The appearance of gene family could affect the function of organsand plant traits by affecting the expression level of protein-coding genes. Whatcontribution the gene family has done to protein translation and how the temperal andspatial expression of the gene family is regulated are interesting. In regulation of genefamily expression, what’s the contribution from the promoters of these genes? In thisstudy, we analyzed the expression of soybean BCCP gene family by promoter andqRT-PCR. The transcripts abundance, promoter regulation element and activaty,methylation and evolution of this gene family were performed.BCCP is a subunit of acetyl coenzyme A carboxylase, which is the keyrate-limiting enzyme of fatty acid synthesis. One purpose of this study is toinvestigate expression patterns of different member of BCCP gene family during seeddevelopment. Through the soybean genome database, Promoter sequence informationof seven members of soybean BCCP gene family was obtained. All these promoterswere cloned from soybean by PCR. Promoter-GUS expression vectors wereconstructed and were transffered into tobacco plant through Agrobacterial mediatedmethod. Promoter activaty in different tissues of transgenic tobacco was analyzed byGUS staining. Promoter p19g03530showed strong and constitutive transcriptionalactivity in transgenic plants, and GUS activity was observed in seeds, and plantdevelopmental stages. Promoter p18g47850showed high activities in seedtorpedo-shape embryo period relatively. In transgenic tobacco plants, promoterp18g47850showed low activities in seed torpedo-shape embryo period. Promoterp13g44040showed low activities in cotyledon at torpedo-shape embryo satge. Mature leavies from transgenic plants were taken for GUS staining, and the result showed thatpromoters of BCCP family genes has different activities in leaves. Other transgenicplants are still growing. Real-time quantitative PCR was carried out to examine theexpression of all these soybean BCCP genes. The results showed that the expressionlevel of BCCP19g03530are distinct high in seeds than in other tissues.Chalcone-flavanone isomerase (CHI) is an important enzyme of Phenylalaninemetabolic pathways, in which the flavonoids are the end products. Flavonoids areinvolves in a variety of plant biological processes, such has pigment formation,pheromone synthesis, response against pathogenic microorganisms, legumenodulation and so on. The full-length peanut typeⅡ CHI (CHI II) cDNA andgenomic DNA were cloned in this study. The cDNA length of peanut CHI II was1184bp with an ORF of675bp, encoding a peptide of224amino acids. The genomicsequence of peanut CHIⅡ was2027bp in length containing four exons and threeintrons. Primers were designed accoding to the coding sequence, and the promoterregion of CHIⅠand CHIⅡ was cloned by chromosome walking. Cis-elements ofthese promoters were analyzed using bioinformatic method. The results showed thatCHIⅡ promoter was most probably root specific. Real-time quantitative PCR resultsconfirmed the bioinformatic predicted result that CHI II was root specific. Theexpression of CHI II in different peanut cultivars (with different color: green orpurpose in color) was measured. The results showed that the expression of this genedid not correlated with the color of the peanut plants.Totally,17homologous CHI genes from different plant species were downloadedfrom NCBI and Phytozome Databases, and these sequences were used to analyse theevolution model of this gene family use PAML software. The result showed that CHIgenes were under purifying selection during evolution, and some amino acid sitesshowed neutral selection.In this study, different methods were employed to anlysis the expressionregulation of BCCP and CHI gene families. The evolution of CHI gene family wasdiscussed. This study provided valuable information for futher investigation aof thesetwo gene families.