湿地松木质部和针叶松脂合成基因分析

Genes Related to Resin Biosynthesis in Xylem and Needle of Pinus elliottii

摘要:

为挖掘湿地松(Pinus elliottii)松脂合成相关的基因，对不同采脂期的木质部和针叶进行高通量转录组测序，与火炬松(Pinus taeda)参考基因组进行比对，共获得了68 211条unigenes，546 356 450条clean reads，平均比对率达90.21%。将不同时期木质部、木质部与针叶间进行两两对比，以P＜0.05，|log₂FoldChange|＞1.0为标准来筛选差异基因，并进行GO和KEGG富集分析。结果表明，参与萜类物质合成的差异基因有133个，其中大部分富集在MEP途径，从差异基因中挑选8个产脂相关的候选基因进行RT-qPCR验证，确定HMGR、DXS、TPS、ABC转运蛋白基因与产脂存在关联性。通过转录组测序与分析，挖掘出133个参与松脂萜类物质合成相关的差异基因，其中萜烯合酶基因(TPS)和ABC转运基因在正调控萜类物质合成中发挥关键作用。

Abstract:

In order to explore the genes related to pine resin biosynthesis in Pinus elliottii, a total of 12 samples of xylem at different resin collection stages and needles were used for high-throughput transcriptome sequencing. Compared with the reference genome of P. taeda, a total of 68 211 unigenes and 546 356 450 clean reads were obtained with an average mapping rate of 90.21%. The expression profiles between needles and xylem were compared in pairs. The differentially expressed genes (DEGs) were selected according to P＜0.05,|log₂foldchange|> 1.0, and then annotated by GO and KEGG enrichment analysis. The results showed that 133 DEGs involved in terpene synthesis, most of which were enriched in MEP pathway. Eight candidate genes related to pine resin biosynthesis were selected from the DEGs and validated by RT-qPCR, in which HMGR, DXS, TPS, ABC transporter genes were highly correlated with the rosin production. Therefore, 133 differential genes related to pine resin biosynthesis were mined through transcriptome sequencing, and among which three TPS genes and two ABC transporter genes positively regulate terpenoid synthesis.