Research Of Gene Cloning And Molecular Evolution Of Chalcone Synthase Gene(CHS) From Apocynum Venetum L

Based on the condition of current environment pressure and the worsening natural situation, the use of degraded land’s rational development and efficient using has been paid more and more attention. For the recovery’and utilization of degraded land, not only rely on the cultivation of high resistant plants, more importantly, but understand the mechanism of its highly adaptable to the habitat, which are helpful to ultilize the barren land. In this study, using desert plants Apocynum venetum L as materials, through RT-PCR (reverse transcription polymerase chain reaction) and RACE (rapid amplification of cDNA ends) to gain Chalcone Synthase gene(AvCHS), we evaluated the gene expressive quantity of AvCHS in different plant components by semi-quantitative analysis, researched AvCHS molecular evolution through bioinformatics methods and database resources. Results are as follows:1. Cloning of AvCHS. Chalcone Synthase (CHS) is the flavonoid synthetic precursor and the key enzyme of synthetizing secondary metabolites. AvCHS, a 1476 bp cDNA fragment, contain a full length 1170bp ORF, and code 389 amino acids residue(aa).2. Analysis of AvCHS blast.The highest consistency appears among AvCHS, Rhus chinensis Mill and Prunus domestica L CHS gene; almost all the blast CHS gene nucleotide sequences obtained 78% consistency with AvCHS. CHS genes are conservative in higher plant.3. Semi-quantitative analysis for gene expressive quantity of A.venetum L AvCHS in different modules. By RT-PCR, with 18S rDNA PCR product as an internal standard, make semi-quantitative analysis to the gene expressive quantity of AvCHS in different plant components as roots, stems, leaves and flowers. The results showed that:Is the highest expression of flowers, and the second is the root and leaves. Apocynum strong ecological adaptability and economic characteristics have a direct relationship with the large gene expressive quantity of AvCHS in reproductive and nutritional components.4. Molecular evolution study on AvCHS.By sequence alignment,phylogenetic tree were mapped with distance method. Bioinformatics analysis confirmed that AvCHS belongs CHS gene superfamily, the sequence similarity reached 92%; CHS supergene family is divided into two subfamilies in its evolution. Genetic Distance of two subfamilies is 0.048, AvCHS belongs to subfamily I. CHS have the same gene action as guide protein synthesis and trait expression. Two categories that divided into have high amino acid sequence identity. Group I which AvCHS belongs to is divided into more than a dozen kinds. CHS protein structure is conserved overall, a few members appear subtle differences in the structure and function under environmental factors.The results make clear AvCHS gene concrete structure, definite its position in CHS gene superfamily. Divided into different types by ecological characteristics phylogeny, we lay the foundation for exploring the specific gene and developping gene resources.