Multiple R2R3-MYB Transcription Factors Involved in the Regulation of Anthocyanin Accumulation in Peach Flower.
Anthocyanin accumulation is responsible for flower coloration in peach. Here, we report the identification and functional characterization of eight flavonoid-related R2R3-MYB transcription factors, designatedPpMYB10.2, PpMYB9, PpMYBPA1, Peace, PpMYB17, PpMYB18, PpMYB19, andPpMYB20, respectively, in peach flower transcriptome.PpMYB10.2andPpMYB9are able to activate transcription of anthocyanin biosynthetic genes, whilstPpMYBPA1andPeacehave a strong activation on the promoters of proanthocyanin (PA) biosynthetic genes.PpMYB17-20show a strong repressive effect on transcription of flavonoid pathway genes such asdihydroflavonol 4-reductase. These results indicate that anthocyanin accumulation in peach flower is coordinately regulated by a set of R2R3-MYB genes. In addition,PpMYB9andPpMYB10.2are closely related but separated into two groups, designated MYB9 and MYB10, respectively.PpMYB9shows a strong activation on thePpUGT78A2promoter, but with no effect on the promoter ofPpUGT78B(commonly calledPpUFGTin previous studies). In contrast,PpMYB10.2is able to activate thePpUFGTpromoter, but not for thePpUGT78A2promoter. Unlike theMYB10gene that is universally present in plants, theMYB9gene is lost in most dicot species. Therefore, thePpMYB9gene represents a novel group of anthocyanin-related MYB activators, which may have diverged in function from theMYB10genes. Our study will aid in understanding the complex mechanism regulating floral pigmentation in peach and functional divergence of the R2R3-MYB gene family in plants.
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences Wuhan, China.
Hui
H
Zhou
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
Qian
Q
Peng
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences Beijing, China.
Jianbo
J
Zhao
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
Albert
A
Owiti
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences Beijing, China.
Fei
F
Ren
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; Sino-African Joint Research Center, Chinese Academy of SciencesWuhan, China.
Liao
L
Liao
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; Sino-African Joint Research Center, Chinese Academy of SciencesWuhan, China.
Lu
L
Wang
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; Sino-African Joint Research Center, Chinese Academy of SciencesWuhan, China.
Xianbao
X
Deng
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences Beijing, China.
Quan
Q
Jiang
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of SciencesWuhan, China; Sino-African Joint Research Center, Chinese Academy of SciencesWuhan, China.
Yuepeng
Y
Han
R2R3-MYB; anthocyanin; flower coloration; peach; proanthocyanin