Potato Anthocyanins Candidate Transcriptional Activation Of Gene Cloning And Analysis

Anthocyanin has some important physiological functions, such as antioxidation, antimutation, antiproliferation etc. Purple potato (Solanum tuberosum) is intituled healthy food for its abundant anthocyanin. Pigmentation patterns and the intensity of anthocyanin in various plant tissues are coordinately controlled by the expression of anthocyanin transcriptional activator genes in plants. Therefore, cloning and identification of anthocyanin transcriptional activator genes (myc, myb and wd40-like genes) of S. tuberosumare are very useful for elucidation the regulatory mechanism of anthocyanin pigmentation in S. tuberosum and for controlling the pigmentation in it by using the anthocyanin transcriptional activator genes as switches.In our study, candidate anthocyanin regulatory gene stwd40 and three fragments of candidate anthocyanin regulatory genes stmyc538, stmyc450 and stmyb499 were isaolated from S. tuberosum purple tissues by using RT-PCR and Rapid Amplification of cDNA Ends(RACE) technique. Sequences analysis showed that the full-length cDNA of stwd40 with 1292 bp, contains an ORF of 1154 bp composed of 362 amino acid residues, encoding a WD40 repeat ptotein, which has high identity with Petunia hybrida WD40 repeat protein AN11 (86%). The features typical of WD40 repeats region are located towards the C-teminus of protein between amino acid residues 97 to 292. The myc-related fragments, stmyc450 with 450 bp and stmyc538 with 538 bp were also amplified, their sequences showed >87% identity with petunia jaf13. As well, the stmyb499 fragment with 499 bp was amplified, the cDNA sequences showed 95% identity with the known potato cultivar Y83-1 an2 mRNA (AY841131) which encoded a R2R3-MYB regulator gene.Furthermore, The spatial expression patterns of these genes and fragments were presented by using semi-quantitative RT-PCR analysis. The results indicated that the expression level of stwd40 was almost detected in every tissue which we tested, and it in stems, tubers skin and roots was more than that in others. The expression of stmyc450 in tubers skin and stems was higher than that in leaves and roots, but it was not detected in tubers flesh. The expression level of stmyc538 in tubers flesh and stems were more than that in leaves, and roots, but it was not detected in tubers skin. The expression level of stmyb499 was prominent in tubers skin and declined in other tissues. The expression level of stmyc1 ,which cloned by yanlan-Huang in 2005, in tubers flesh, stems and roots was higher than that in other tissues. Basis of our research, we presumed that these genes and fragments were correlated with the anthocyanin transcriptional regulator genes in S. tuberosum. These results would provide the valuable information for elucidation the regulatory mechanism of anthocyanin biosstynthesis in S. tuberosum.