AUTHOR=Yan Xin , Ding Wenjie , Wu Xiuyi , Wang Lianggui , Yang Xiulian , Yue Yuanzheng 

TITLE=Insights Into the MYB-Related Transcription Factors Involved in Regulating Floral Aroma Synthesis in Sweet Osmanthus

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.765213

DOI=10.3389/fpls.2022.765213

ISSN=1664-462X

ABSTRACT=<p>As an important member of the <italic>MYB</italic> transcription factor (TF) family, the <italic>MYB-related</italic> TFs play multiple roles in regulating the synthesis of secondary metabolites and developmental processes, as well as in response to numerous biotic and abiotic stressors in plants. However, little is known regarding their roles in regulating the formation of floral volatile organic compounds (VOCs). In this study, we conducted a genome-wide analysis of MYB-related proteins in sweet osmanthus; 212 <italic>OfMYB-related</italic> TFs were divided into three distinct subgroups based on the phylogenetic analysis. Additionally, we found that the expansion of the <italic>OfMYB-related</italic> genes occurred primarily through segmental duplication events, and purifying selection occurred in all duplicated gene pairs. RNA-seq data revealed that the <italic>OfMYB-related</italic> genes were widely expressed in different organs of sweet osmanthus, and some showed flower organ/development stage-preferential expression patterns. Here, three <italic>OfMYB-related</italic> genes (<italic>OfMYB1R70/114/201</italic>), which were expressed nuclearly in floral organs, were found to be significantly involved in regulating the synthesis of floral VOCs. Only, <italic>OfMYB1R201</italic> had transcriptional activity, thus implying that this gene participates in regulating the expression of VOC synthesis related genes. Remarkably, the transient expression results suggested that <italic>OfMYB1R70</italic>, <italic>OfMYB1R114</italic>, and <italic>OfMYB1R201</italic> are involved in the regulation of VOC synthesis; <italic>OfMYB1R114</italic> and <italic>OfMYB1R70</italic> are involved in accelerating β-ionone formation. In contrast, <italic>OfMYB1R201</italic> decreases the synthesis of β-ionone. Our results deepen our knowledge of the functions of <italic>MYB-related</italic> TFs and provide critical candidate genes for the floral aroma breeding of sweet osmanthus in the future.</p>