| 摘要: |
| 【目的】探究不同烤烟品种（系）二萜类物质代谢特点，为高香气烟草品种的选育提供理论依据。【方法】选取8306、红花大金元、云烟87、K326、豫烟11、豫烟12共计6个烤烟品种（系），通过q-PCR技术对二萜类物质合成关键基因DXR、CYC-1、CYP71D16、CPS2、ABS进行检测，应用GC-MS技术对二萜类物质及调制后二萜类降解产物进行测定，并对其感官质量进行评价。【结果】DXR、CYC-1和CYP71D16在8306和豫烟11中高表达，CPS2仅在产生顺 冷杉醇品种（系）8306和豫烟11中高表达，ABS在不产生顺 冷杉醇的品种K326、红花大金元、云烟87和豫烟12中高表达。在产生顺-冷杉醇品种（系）中CPS2基因第二外显子第456位碱基表现为G，在不产生顺-冷杉醇品种（系）中碱基表现为T。8306和豫烟11具有较高的西柏三烯二醇含量，顺-冷杉醇和赖百当烯二醇仅在8306、豫烟11中检测出。调制后，8306和豫烟11的西柏烷类降解产物含量较高，各品种（系）均未检测出赖百当类降解产物。豫烟11的感官质量评分最高，表现为香气质和柔细度稍好、浓度稍浓、刺激性稍小、灰色较白。二萜类物质总量与香气量、柔细度、杂气、刺激性和感官质量评价总分呈极显著正相关；二萜类降解产物总量与香气质呈极显著正相关。【结论】不同烤烟品种(系)二萜类物质及其降解产物、基因表达量存在明显差异。8306和豫烟11西柏烷类化合物含量较高的主要原因是，DXR和CYC-1、CYP71D16的上调表达。部分品种不产生顺-冷杉醇与CPS2碱基突变表达受阻有关。结合感官质量评价结果认为，二萜类物质及其降解产物能够起到增添香味、柔和烟气的作用。 |
| 关键词: 烤烟 腺毛 二萜化合物 基因表达 |
| DOI： |
| 分类号: |
| 基金项目:中国烟草总公司项目“河南豫浓香型优质烤烟品种筛选与配套技术的应用研究”(201841000270035) |
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| Difference in expression and metabolism of key genes for diterpenoid biosynthesis between different flue-cured tobacco |
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ZHANG Siqi,HE Jia,ZHOU Fang,et al
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| Abstract: |
| 【Objective】This experiment was conducted to explore metabolic characteristics of diterpenoids in different flue-cured tobacco varieties (lines）.【Method】Six flue-cured tobacco varieties （lines） including 8306,Honghuadajinyuan,Yunyan 87,K326,Yuyan 11,and Yuyan 12 were selected.The expression patterns of key genes for diterpenoid biosynthesis including DXR,CYC-1,CYP71D16,CPS2 and ABS were detected by q-PCR.The diterpenoids and degradation products after modulation were determined by GC-MS and the sensory quality was evaluated.【Result】The expression levels of DXR,CYC-1 and CYP71D16 in 8306 and Yuyan 11 were higher,CPS2 was highly expressed only in cis-abienol producing varieties of 8306 and Yuyan 11,while ABS was highly expressed in cis abienol non producing K326,Honghuadajinyuan,Yunyan 87 and Yuyan 12.The 456 base of the second exon of CPS2 was expressed as G in cis-abienol producing varieties,while the base was expressed as T in other varieties.Yuyan 11 and 8306 had higher content of cembratrienediol,and cis-abienol and labdenediol were only detected in Yuyan 11 and 8306.After modulation,8306 and Yuyan 11 had higher cembratrienediol degradation products,while labdanoids degradation products were not detected.Yuyan 11 had the highest sensory quality score characterized by slightly better aroma,slightly higher concentration,slightly softer,less irritating and grayish gray.The total amount of diterpenoids was significantly correlated with total amount of aroma,softness,gas,irritation and sensory quality.The total amount of diterpenoid degradation products was significantly correlated with aroma.【Conclusion】There were significant differences in diterpenoids and degradation products and gene expression levels among flue-cured tobacco varieties （lines）.The main reason for high cembratrienediol in 8306 and Yuyan 11 was the up-regulation of DXR and CYC-1,CYP71D16.Some cis-abienol non-producing varieties were associated with the inhibition of CPS2 expression.Combined with sensory quality evaluation,diterpenoids and degradation products can enhance flavor and soften gas. |
| Key words: flue-cured tobacco trichome diterpenoid gene expression |
