Transcriptome Analysis Revealed the Dynamic Fruit Oil Accumulation of Symplocos paniculata

Symplocos paniculata is a shrub or small tree with high fruit oil content. It can be used as potential feedstocks for biodiesel and cooking oil production in China. To understand the regulatory molecular mechanism of fruit oil accumulation, the transcriptome analysis was conducted using the fresh fruits at four different development stages (10, 80,140, and 170 days after flowering). Approximately 28 million high quality clean reads were generated, and they were trimmed and assembled into 182,904 non-redundant putative transcripts with a mean length of 592.91bp and N50 length of 785 bp, respectively. Based on the functional annotation through Basic Local Alignment Search Tool (BLAST) program with public protein database, the key enzymes involved in lipid metabolism were identified, and a schematic diagram of the pathway and temporal expression patterns of lipid metabolism was established. About 13,939 differentially expressed unigenes were screened out using DESeq method. The transcriptional regulatory patterns of the identified enzymes were comparatively analyzed with the dynamic oil accumulation along with the fruit development of S. paniculata. In addition, six vital genes related to lipid metabolism were selected and validated by quantitative real-time PCR (qRT-PCR). Results in this study will provide references for researching the woody oil plants.