Cloning and Expression Analysis of <i>RrMYB</i>113 Gene Related to Anthocyanin Biosynthesis in <i>Rosa rugose</i>

Abstract

Anthocyanin is one of water-soluble natural pigments widely existing in flowers, fruits, stems, leaves and seeds of plants, and it is the major factor conferring pink or red to the petals of Rosa rugose . MYB TFs play an important role in the anthocyanin synthesis in plants. This work aimed to clone the MYB gene related to anthocyanin synthesis in the petals of Rosa rugose , and explore the relationship between them to lay a good foundation for gene engineering improvement of R. rugose . Based on the transcriptional data, a full-length cDNA sequence of MYB Gene, RrMYB 113 (GenBank accession Nos MG720012), was cloned at the first time from the petals of Rosa rugose “Zi zhi” with RT-PCR and RACE methods. The full-length cDNA is 885 bp with an open reading frame of 654 bp, encoding 216 amino acids. The derived RrMYB 113 protein has a molecular weight of 25,297.64 Da, a calculated pI of 9.61, a R2R3-MYB domain and bHLH binding domain, and it also has the signature motifs ((A/S/G)NDV and KPRPR(T/S)), thus belonging to Sg6 R2R3-MYB subfamily. In the secondary structure of RrMYB 113 protein, there is 37.04% α -helix, 39.81% random coil, 14.81% extended peptide chain, and 8.33% β -corner. There is no transmembrane domain and no signal peptide cleavage site, seventeen Ser phosphorylation sites, fifteen Thr phosphorylation sites, four Tyr phosphorylation sites, and no O-glycosylation sites. The expression of RrMYB 113 increased with the color deepening in petals, and it expressed at a higher level in petals than in other tissues of R. rugose “Zi zhi”. These results are meaningful to reveal that RrMYB 113 might be an important regulator in anthocyanin biosynthesis and coloration in the petals of R. rugose .