Full-length transcriptome of <i>Camellia perpetua</i> reveals candidate <i>SCPL</i>1<i>A</i> gene family members involved in galloylated catechins biosynthesis

Catechins includ galloylated catechins and non-galloylated catechins, among which galloylated catechins exhibit stronger antioxidant, anti-inflammatory and anti-cancer activities. Section <i>Chrysantha</i> Chang, the only group of yellow <i>Camellia</i> with rich catechins in their flowers, is a common health drink in southern China. To date, few studies have examined galloylated catechins biosynthesis in flowers of this group. To enrich the genetic information of the galloylated catechins biosynthesis, the ONT sequencing platform was used to perform full-length transcriptome sequencing of <i>C. perpetua</i> flowers and 7,972,574 transcripts was identified, including 42,883 simple sequence repeats (SSRs), 41,961 coding sequences (CDSs) and 2,602 long non-coding RNAs (lncRNAs). 36,516 transcripts were successfully annotated, and 147 critical enzyme-encoding genes were identified as involved in the galloylated catechins biosynthesis pathway, including 17 <i>CpSCPL</i>1<i>A</i> genes. Bioinformatics analysis revealed that each <i>CpSCPL</i>1<i>A</i> protein consisted of 427-506 amino acids, and all <i>CpSCPL</i>1<i>A</i> proteins were divided into 5 groups with conserved motifs 1, 4, 5, 6 and 8. Based on the correlation analysis between the gene expression of 17 <i>CpSCPL</i>1<i>A</i> genes and the content of galloylated catechins, 11 candidate <i>CpSCPL</i>1<i>A</i> genes were identified to be involved in the biosynthesis of 4 types of galloylated catechins in <i>C. perpetua</i> flowers. The results enrich the transcriptome data for <i>C. perpetua</i> and provide valuable insights into the importance of the <i>CpSCPL</i>1<i>A</i> gene family members in the galloylated catechins biosynthesis.