AUTHOR=Wang Ning , Shu Xiaochun , Zhang Fengjiao , Zhuang Weibing , Wang Tao , Wang Zhong 

TITLE=Comparative Transcriptome Analysis Identifies Key Regulatory Genes Involved in Anthocyanin Metabolism During Flower Development in Lycoris radiata

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.761862

DOI=10.3389/fpls.2021.761862

ISSN=1664-462X

ABSTRACT=<p><italic>Lycoris</italic> is used as a garden flower due to the colorful and its special flowers. Floral coloration of <italic>Lycoris</italic> is a vital trait that is mainly regulated via the anthocyanin biosynthetic pathway. In this study, we performed a comparative transcriptome analysis of <italic>Lycoris radiata</italic> petals at four different flower development stages. A total of 38,798 differentially expressed genes (DEGs) were identified by RNA sequencing, and the correlation between the expression level of the DEGs and the anthocyanin content was explored. The identified DEGs are significantly categorized into ‘flavonoid biosynthesis,’ ‘phenylpropanoid biosynthesis,’ ‘Tropane, piperidine and pyridine alkaloid biosynthesis,’ ‘terpenoid backbone biosynthesis’ and ‘plant hormone signal transduction’ by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The candidate genes involved in anthocyanin accumulation in <italic>L. radiata</italic> petals during flower development stages were also identified, which included 56 structural genes (especially <italic>LrDFR1</italic> and <italic>LrFLS</italic>) as well as 27 key transcription factor DEGs (such as <italic>C3H</italic>, <italic>GATA</italic>, <italic>MYB</italic>, and <italic>NAC</italic>). In addition, a key structural gene namely <italic>LrDFR1</italic> of anthocyanin biosynthesis pathway was identified as a hub gene in anthocyanin metabolism network. During flower development stages, the expression level of <italic>LrDFR1</italic> was positively correlated with the anthocyanin content. Subcellular localization revealed that LrDFR1 is majorly localized in the nucleus, cytoplasm and cell membrane. Overexpression of <italic>LrDFR1</italic> increased the anthocyanin accumulation in tobacco leaves and <italic>Lycoris</italic> petals, suggesting that <italic>LrDFR1</italic> acts as a positively regulator of anthocyanin biosynthesis. Our results provide new insights for elucidating the function of anthocyanins in <italic>L. radiata</italic> petal coloring during flower development.</p>