Abstract: The patchouli oil is mainly stored in the peltate trichome on the aerial part of patchouli. The total RNA was extracted from the leaf and the complete cDNA sequence of patchoulol synthase gene (PatPTS) was cloned via PCR. The virus induced gene silencing(VIGS) system was constructed in patchouli to characterize the function of PatPTS, and the tobacco rattle virus (TRV) was used to silence PatPTS expression. GC-MS and qRT-PCR were used to detect the variations of these sesquiterpenes and PatPTS transcription in leaf after VIGS infection. The contents of β-patchoulene, β-elemene, trans-β-caryophyllene and (-)-patchoulol were decreased significantly after infection for 2 weeks, and the expression level of PatPTS showed similar pattern; which meaned PatPTS was in charge of the biosynthesis of the major components of patchouli oil. The results indicated that the VIGS system in patchouli was successfully established, and silence effects on secondary metabolites production and gene expression were the most effective after infection for 2 weeks, which provided an effective method for the fast screen of gene functions.

Key words: VIGS, Pogostemon cablin, PatPTS, sesquiterpenes

摘要： 广藿香精油主要存贮在植物地上组织的盾状腺毛中。提取广藿香（马来西亚品系）叶片的总RNA后，通过PCR技术扩增得到广藿香醇合酶基因（PatPTS）的全长cDNA序列，共编码552个氨基酸，与GenBank中已报道的印度广藿香中广藿香醇合酶的氨基酸序列存在3.6%的差异。使用烟草脆裂病毒（tobacco rattle virus，TRV），选取PatPTS作为沉默目的基因，在广藿香中构建病毒诱导基因沉默（VIGS）体系，进一步利用该体系在广藿香中鉴定PatPTS基因的功能。病毒侵染广藿香叶片后，分别选取不同的时间点，使用GS-MS与qRT-PCR检测PatPTS催化产物和转录水平的变化，结果发现：β-广藿香烯、β-榄香烯、石竹烯、广藿香醇等倍半萜成分的含量在VIGS侵染后第2周明显下降，1周和3周效果不明显；PatPTS转录本下降趋势与其调控的倍半萜含量变化趋势类似；表明PatPTS基因负责了广藿香精油主要倍半萜成分的合成。说明广藿香中VIGS体系已初步建立，并在侵染植物2周后诱导基因沉默和干扰次生代谢产物合成的效果最好，为在广藿香中快速研究基因功能打下基础。

关键词: VIGS, 广藿香, 广藿香醇合酶, 倍半萜类化合物