山茶花花香成分鉴定及相关基因的转录组分析  

Identification of Floral Aroma Components and Transcriptome Analysis of Related Genes in Camellia japonica L.

作　　者：陈艺荃 林榕燕 孔兰 方能炎 樊荣辉[1] 钟淮钦[1] CHEN Yiquan;LIN Rongyan;KONG Lan;FANG Nengyan;FAN Ronghui;ZHONG Huaiqin(Institute of Crop Sciences(Fujian Germplasm Resources Center),Fujian Academy of Agricultural Sciences,Fuzhou,Fujian 350013)

机构地区：[1]福建省农业科学院作物研究所(福建省种质资源中心),福建福州350013

出　　处：《核农学报》2024年第12期2281-2293,I0001,共14页Journal of Nuclear Agricultural Sciences

基　　金：福建省科技计划项目-福建省属公益科研院所基本科研专项(2022R1032007);“5511”协同创新项目(XTCXGC2021016);福建省农科院特色花卉科技创新团队项目(CXTD2021010-2)。

摘　　要：为了探究山茶花品种香太阳、香妃和赤丹不同花期花瓣中的挥发性成分,采用顶空-固相微萃取(HS-SPME)和气相色谱-质谱联用(GC-MS)技术,并结合相对气味活度值(ROAV)鉴定关键香气成分。通过转录组测序技术,探究山茶花花香生物合成途径及花香差异形成相关基因。结果表明,3个山茶花品种的主要花香成分由单萜和苯环型/苯丙素类化合物构成,单萜种类最多,品种间成分和含量有明显差异。共鉴定出16种特征香气成分,其中,芳樟醇为关键香气成分,对山茶花整体香气的表达起主控作用。从转录组数据中筛选出7个甲羟戊酸(MVA)途径结构基因和8个甲基赤藓醇磷酸(MEP)途径结构基因,其中CaDXS2、CaDXS3为单萜合成关键结构基因。筛选出萜类合成途径关键酶基因CaLIS/NES1和CaLIS/NES2及苯环型/苯丙素类化合物合成途径关键酶基因CaPAR和CaSAMT,推测上述基因在花香关键成分芳樟醇、2-苯乙醇和水杨酸甲酯的合成中发挥关键作用。对差异表达基因进行实时荧光定量PCR(qRT-PCR)和RNA-seq验证,结果显示二者拟合度较高,因此认为RNA-seq测序结果具有较高的准确性。研究结果为山茶花花香形成机理研究提供了依据。In order to investigate the volatile components in the petals of Camellia varieties Scented Sun,High Fragrance and Chidan at different flowering stages,HS-SPME and GC-MS techniques were employed in conjunction with relative odor activity values(ROAVs)to identify key aroma components.By using transcriptome sequencing technology,floral fragrance biosynthesis pathways and genes related to the floral fragrance were explored.The results showed that the main floral aroma components of three varieties consisted of monoterpenes and benzenoids/phenylpropanoids,with the highest concentration of monoterpenes and significant differences in composition and content among the varieties.A total of 16 characteristic aroma components were identified,with linalool being the key aroma component that plays a dominant role in the overall aroma profile of Camellia.Seven structural genes from the mevalonate pathway and eight structural genes from the methylerythritol phosphate pathway were screened from transcriptome data,among these,CaDXS2 and CaDXS3 are key structural genes involved in monoterpene synthesis.Screening of key enzyme genes CaLIS/NES1 and CaLIS/NES2 in the terpenoid synthesis pathway,as well as CaPAR and CaSAMT in the benzenering/phenylpropanoid compound synthesis pathway,suggests that these genes play a crucial role in the synthesis of key components in floral fragrance,such as linalool,2-phenylethanol,and methyl salicylate.The results of qRT-PCR and RNA-seq validation of differentially expressed genes showed a high degree of correlation,indicating that RNA-seq sequencing results have high accuracy.These research results provide a basis for further study on the mechanisms involved in the formation of flower fragrance in Camellia.

关 键 词：山茶花 花香 差异表达基因 萜类化合物 

分 类 号：S685.14[农业科学—观赏园艺]