AUTHOR=Liu Xiaokun , Duan Jingjing , Huo Dan , Li Qinqin , Wang Qiaoyun , Zhang Yanlong , Niu Lixin , Luo Jianrang 

TITLE=The Paeonia qiui R2R3-MYB Transcription Factor PqMYB113 Positively Regulates Anthocyanin Accumulation in Arabidopsis thaliana and Tobacco

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.810990

DOI=10.3389/fpls.2021.810990

ISSN=1664-462X

ABSTRACT=<p><italic>Paeonia qiui</italic> is a wild species of tree peony native to China. Its leaves are purplish red from the bud germination to the flowering stage, and anthocyanin is the main pigment in purplish red leaves. However, the anthocyanin synthesis regulation mechanism in tree peony leaves remains unclear. In this study, an R2R3-MYB, PqMYB113 was identified from the leaves of <italic>P. qiui</italic>. Phylogenetic analysis revealed that PqMYB113 clustered with <italic>Liquidambar</italic> LfMYB113 and grape VvMYBA6. Subcellular location analysis showed that PqMYB113 was located in the cell nucleus. The transient reporter assay suggested that PqMYB113 was a transcriptional activator. The overexpression of <italic>PqMYB113</italic> in <italic>Arabidopsis thaliana</italic> and tobacco (<italic>Nicotiana tabacum</italic>) resulted in increased anthocyanin accumulation and the upregulation of <italic>CHS</italic>, <italic>F3H</italic>, <italic>F3’H</italic>, <italic>DFR</italic>, and <italic>ANS</italic>. The dual luciferase reporter assay showed that PqMYB113 could activate the promoters of <italic>PqDFR</italic> and <italic>PqANS</italic>. Bimolecular fluorescence complementation assays and yeast two-hybrid assays suggested that PqMYB113 could form a ternary MBW complex with PqbHLH1 and PqWD40 cofactors. These results provide insight into the regulation of anthocyanin biosynthesis in tree peony leaves.</p>