Masson pine (Pinus massoniana L.) is one of the most important species for oleoresin production worldwide. However, the mechanism of oleoresin synthesis in masson pine remains poorly studied. We revealed the key differentially expressed genes associated with terpenoid biosynthesis in trees with different yields of oleoresin in different tissues (trunk xylem and needle) during different seasons (spring and autumn) based on the combined application of the SMRT full-length transcriptome and Illumina RNA sequencing under field operations. A total of 76,754 full-length non-redundant transcripts were obtained in the study. Transcriptome data were annotated with KEGG and GO, and they have been shown to be of high quality by qRT-PCR. Chloroplastic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway and cytosolic mevalonate (MVA) pathway genes have different preferences under different conditions. Moreover, the phylogenetic analysis results revealed three classes of DXS genes with different functions. Among the tissue-specific genes, AACT1 was expressed in the trunk xylem at the highest levels, while MCS (1, 4) and HDR2 were significantly upregulated in the needle. Among stage-specific genes, DXS6 and HDS6 were expressed in the trunk xylem in August (autumn) at the highest levels. Furthermore, all of the terpene synthase (TPS) differentially expressed genes (DEGs) were clustered into the gymnosperm-specific TPS-d subfamily, including sesquiterpene synthase and diterpene synthase genes. According to the protein sequence alignment, diTPS1 and diTPS5 with three conserved active sites catalysed the synthesis of diterpene resin acids. In the low-yield oleoresin clone, diTPS (1, 5) and GGPPS (4, 6) were upregulated in the trunk xylem. The integration of the transcriptomic data indicated that the AACT, MCS, HDR, DXS, HDS, and TPS (with two conserved active sites) may play critical roles in the terpenoids biosynthesis of masson pine. The results of our study can be useful for developing an understanding of the coniferous genome and to significantly accelerate confer breeding.

马尾松（马尾松L.）是世界范围内最重要的油脂树脂生产物种之一。然而，在马尾松中油性树脂合成的机理仍缺乏研究。我们基于SMRT全长转录组和Illumina RNA的联合应用，揭示了在不同季节（春季和秋季）不同组织（树干木质部和针头）中具有不同产量油树脂的树木中与萜类生物合成相关的关键差异表达基因。在现场操作下进行排序。该研究共获得76,754个全长非冗余转录本。转录组数据用KEGG和GO标注，并且qRT-PCR显示它们具有高质量。在不同条件下，叶绿体2-C-甲基-D-赤藓糖醇4-磷酸（MEP）途径和胞质甲羟戊酸酯（MVA）途径基因具有不同的偏好。此外，系统发育分析结果显示三类具有不同功能的DXS基因。在组织特异性基因中，AACT1在树干木质部中以最高水平表达，而MCS（1、4）和HDR2在针中显着上调。在特定于阶段的基因中，DXS6和HDS6在8月（秋季）的树干木质部中以最高水平表达。此外，所有的萜烯合酶（TPS）差异表达基因（DEGs）均聚到裸子植物特有的TPS-d亚家族中，包括倍半萜烯合酶和二萜合酶基因。根据蛋白质序列比对，具有三个保守的活性位点的diTPS1和diTPS5催化了二萜树脂酸的合成。在低产量的油树脂克隆中，树干木质部中的diTPS（1、5）和GGPPS（4、6）被上调。转录组数据的整合表明，AACT，MCS，HDR，DXS，HDS和TPS（具有两个保守的活性位点）可能在马尾松的萜类生物合成中起关键作用。我们的研究结果可能有助于发展对针叶树基因组的了解，并极大地促进赋予育种。TPS（具有两个保守的活性位点）可能在马尾松的萜类生物合成中起关键作用。我们的研究结果可能有助于发展对针叶树基因组的了解，并极大地促进赋予育种。TPS和TPS（具有两个保守的活性位点）可能在马尾松的萜类生物合成中起关键作用。我们的研究结果可能有助于发展对针叶树基因组的了解，并极大地促进赋予育种。