Single molecule, full-length transcript sequencing provides insight into the TPS gene family in Paeonia ostii

The tree peony (Paeonia section Moutan DC), one of the traditional famous flowers with both ornamental and medicinal value, was widely used in China. Surprisingly little is known about the full-length transcriptome sequencing in tree peony, limiting the research on its gene function and molecular mechanism. The trehalose phosphate phosphatase (TPS) family genes has been found to affect plant growth and development and the function of TPS genes in Paeonia ostii is unknown.

In our study, we performed single molecule, full-length transcript sequencing in P. ostii. 10 TPS family members were identified from PacBio sequencing for bioinformatics analysis and transcriptional expression analysis.

A total of 230,736 reads of insert (ROI) sequences and 114,215 full-Length non-chimeric reads (FLNC) were obtained for further ORFs and transcription factors prediction, SSR analysis and lncRNA identification. NR, Swissprot, GO, COG, KOG, Pfam and KEGG databases were used to obtain annotation information of transcripts. 10 TPS family members were identified with molecular weights between 48.0 to 108.5 kD and isoelectric point between 5.61 to 6.37. Furthermore, we found that TPS family members contain conserved TPP or TPS domain. Based on phylogenetic tree analysis, PoTPS1 protein was highly similar to AtTPS1 protein in Arabidopsis. Finally, we analyzed the expression levels of all TPS genes in P. ostii and found PoTPS5 expressed at the highest level. In conclusion, this study combined the results of the transcriptome to systematically analyze the 10 TPS family members, and sets a framework for further research of this important gene family in development of tree peony.