Genome-Wide Identification and Expression Analysis of the YTH Domain-Containing RNA-Binding Protein Family in <i>Cinnamomum camphora</i>

oleh: Jingjing Zhang, Sheng Yao, Xiang Cheng, Yulu Zhao, Wenya Yu, Xingyue Ren, Kongshu Ji, Qiong Yu

Format: Article
Diterbitkan: MDPI AG 2024-05-01

Deskripsi

<i>N<sup>6</sup></i>-methyladenosine (m<sup>6</sup>A) is one of the most abundant chemical modifications on mRNA in eukaryotes. RNA-binding proteins containing the YT521-B (YTH) domain play crucial roles in post-transcriptional regulation of plant growth, development, and stress response by reading the m<sup>6</sup>A mark. However, the YTH domain-containing RNA-binding protein family has not been studied in a valuable and medicinal tree such as <i>Cinnamomum camphora</i> (<i>C. camphora</i>) yet. In this study, we identified 10 <i>YTH</i> genes in <i>C. camphora</i>, located on eight out of 12 chromosomes. Phylogenetic analysis revealed that these genes can be classified into two major classes, <i>YTHDF</i> (<i>CcDF</i>) and <i>YTHDC</i> (<i>CcDC</i>). Closely related <i>CcYTHs</i> within the same class exhibited a similar distribution of conserved motifs and domain organization, suggesting functional similarities among these closely related <i>CcYTHs</i>. All CcYTH proteins possessed a highly conserved YTH domain, with <i>CcDC1A</i> containing an additional CCCH domain. The liquid–liquid phase separation (LLPS) predictions indicate that <i>CcDC1A</i>, <i>CcDF1A</i>, <i>CcDF1C</i>, <i>CcDF3C</i>, <i>CcDF4C</i>, and <i>CcDF5C</i> may undergo phase transitions. Quantitative expression analysis revealed that tissue-specific expression was observed fo <i>CcYTHs</i>. Notably, there were two genes, <i>CcDF1A</i> and <i>CcDF5C</i>; both exhibited significantly higher expression levels in various tissues than other genes, indicating that the m<sup>6</sup>A-YTH regulatory network in <i>C. camphora</i> might be quite distinct from that in most plants such as <i>Arabidopsis thaliana</i> (<i>A. thaliana</i>) with only one abundant YTH protein. According to the analysis of the up-stream cis-regulatory elements of these <i>YTH</i> genes, these genes could be closely related to stress, hormones, and development. The following stress response experiments further verified that their expression levels indeed changed under both PEG and NaCl treatments. These findings not only provide a foundation for future functional analysis of <i>CcYTHs</i> in <i>C. camphora</i>, but also provide insights into the functions of epigenetic mark m<sup>6</sup>A in forest trees.