Cloning and Expression of Anthocyanin Biosynthesis Related Gene RrMYB6 in <i>Rosa rugosa</i>

Abstract

R 2 R 3 -MYB transcription factor plays an important role in plant anthocyanin synthesis. Based on the transcriptional database of Rosa rugosa , one MYB transcription factor related to floral color, RrMYB6 , was cloned. By using bioinformatics analysis method, cloning MYB gene and analyzing its function in anthocyanin biosynthesis regulation, we hope to lay a solid foundation for new color variety breeding of R. rugosa . Using the R. rugosa “Zi zhi” as the material, we obtained the total length of cDNA of RrMYB6 by RT-PCR and RACE. By analyzing its bioinformatics, we found that the formula of the protein was C 1491 H 2368 N 452 O 470 S 17 , molecular weight was 34690.97 Da, the theoretical pI was 8.74. In addition, it belonged to unstable protein with an unstable index at 50.59, and it was also a hydrophilic protein with the total average hydrophobic index at -0.847. In the secondary structure of RrMYB6 protein, the Alpha helix accounted for 32.35%, random coil was 47.39%, extended strand was 11.11%, and beta turn was 9.15%. The sequence analysis showed that RrMYB6 had a typical R 2 R 3 -MYB domain and bHLH binding domain, and it also had an N1, C1, C2 inhibitory motif, belonging to the Sg4 subfamily MYB protein. What’s more, evolutionary analysis indicated that the RrMYB6 protein was closely related with the MYB protein in Rosacea family, while it was far from those in other families. The expression analysis showed that RrMYB6 protein decreased with the color of petals deeping, and its expression was the lowest in the petals while the highest in stamens. According to the above results, it was speculated that RrMYB6 was involved in regulating the anthocyanin synthesis of R. rugosa , which belonged to negative regulatory mechanism.