AUTHOR=Abbas Farhat , Ke Yanguo , Zhou Yiwei , Yu Yunyi , Waseem Muhammad , Ashraf Umair , Wang Chutian , Wang Xiaoyu , Li Xinyue , Yue Yuechong , Yu Rangcai , Fan Yanping 

TITLE=Genome-Wide Analysis Reveals the Potential Role of MYB Transcription Factors in Floral Scent Formation in Hedychium coronarium

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.623742

DOI=10.3389/fpls.2021.623742

ISSN=1664-462X

ABSTRACT=<p>The MYB gene family is one of the largest groups of transcription factors (TFs) playing diverse roles in several biological processes. <italic>Hedychium coronarium</italic> (white ginger lily) is a renowned ornamental plant both in tropical and subtropical regions due to its flower shape and strong floral scent mainly composed of terpenes and benzenoids. However, there is no information available regarding the role of the MYB gene family in <italic>H. coronarium</italic>. In the current study, the MYB gene family was identified and extensively analyzed. The identified 253 <italic>HcMYB</italic> genes were unevenly mapped on 17 chromosomes at a different density. Promoter sequence analysis showed numerous phytohormones related to <italic>cis</italic>-regulatory elements. The majority of <italic>HcMYB</italic> genes contain two to three introns and motif composition analysis showed their functional conservation. Phylogenetic analysis revealed that HcMYBs could be classified into 15 distinct clades, and the segmental duplication events played an essential role in the expansion of the <italic>HcMYB</italic> gene family. Tissue-specific expression patterns of <italic>HcMYB</italic> genes displayed spatial and temporal expression. Furthermore, seven <italic>HcMYB</italic> (<italic>HcMYB7/8/75/79/145/238/248</italic>) were selected for further investigation. Through RT-qPCR, the response of candidates <italic>HcMYB</italic> genes toward jasmonic acid methyl ester (MeJA), abscisic acid (ABA), ethylene, and auxin was examined. Yeast one-hybrid (Y1H) assays revealed that candidate genes directly bind to the promoter of bottom structural volatile synthesis genes (<italic>HcTPS1</italic>, <italic>HcTPS3</italic>, <italic>HcTPS10</italic>, and <italic>HcBSMT2</italic>). Moreover, yeast two-hybrid (Y2H) assay showed that HcMYB7/8/75/145/248 interact with HcJAZ1 protein. In <italic>HcMYB7/8/79/145/248</italic>-silenced flowers, the floral volatile contents were decreased and downregulated the expression of key structural genes, suggesting that these genes might play crucial roles in floral scent formation in <italic>H. coronarium</italic> by regulating the expression of floral scent biosynthesis genes. Collectively, these findings indicate that <italic>HcMYB</italic> genes might be involved in the regulatory mechanism of terpenoids and benzenoid biosynthesis in <italic>H. coronarium</italic>.</p>