北苍术转录组分析及倍半萜类生物合成关键基因挖掘

Transcriptomic analysis of Atractylodes chinensis and elucidation of genes in sesquiterpenes biosynthesis

倍半萜类化合物是北苍术主要活性成分及质量控制指标成分。为研究北苍术倍半萜类化合物生物合成通路,利用Illumina HiSeqTM 2000 150PE高通量测序平台对北苍术根茎进行转录组测序,得到8.86 G数据, 59 065 569条高质量reads。Trinity组装获得50 330条条带,平均长度1 214 nt。所有条带在NR、NT、Pfam、KOG、Swissprot、KEGG、GO数据库中得到注释,按GO功能分类将其归为3大类53个分支;KEGG分析发现共有11 235条条带参与130个KEGG标准代谢通路, 421条条带参与21个次生代谢标准通路,其中14条条带参与MVA途径关键酶的生物合成, 12条条带参与MEP途径关键酶的生物合成。实时荧光定量PCR (qRT-PCR)揭示倍半萜类合成关键基因FPPS、HMGR和DXS在北苍术不同器官中均有表达,在茎、根茎、花和越冬芽中相对表达量较高,且HMGR、DXS基因的相对表达量高于FPPS基因。本文为北苍术倍半萜类生物合成途径和分子调控机制的研究提供参考。

Sesquiterpenes are the main active constituents and the index components for the quality control of Atractylodes chinensis. To study the sesquiterpenes biosynthesis, rhizomes of A. chinensis were subjected to a high-throughput transcriptomic sequencing analysis by Illumina HiSeqTM 2000 150 PE. A total of 8.86 G clean data resulting in 59 065 569 clean reads were generated. Trinity assembly yielded 50 330 unigenes, with an average of 1 214 nt. Functional annotation revealed that all unigenes were successfully annotated in the NR, NT, Pfam, KOG, Swiss-prot, KEGG and GO databases. GO classification contained 3 major groups with 53 subgroups. KEGG analysis indicated that 11 235 unigenes were implicated in 130 KEGG standard metabolic pathways, and 421 unigenes were related to 21 standard secondary metabolic pathways, among which 14 and 12 unigenes were involved in the biosynthesis of key enzymes in MVA and MEP pathways respectively. qRT-PCR analyze showed that FPPS, HMGR and DXS genes were expressed in different organs of A. chinensis, especially in stems, rhizomes, flowers and hibernacula, meanwhile, the relative expression levels of HMGR and DXS genes were higher than FPPS gene. This study provide a fundamental basis for sesquiterpenes biosynthesis and molecular regulatory mechanism in A. chinensis.