4种百合不同花期花香成分鉴定与关键基因表达研究

Identification of fragrance constituents and expression analysis of key genes in four lily varieties at different flowering stages

使用顶空固相微萃取(HS-SPME)和气相色谱-质谱(GC-MS)联用技术,对4个百合(Lilium spp.)品种初花期和盛花期的花朵进行花香成分分析,并利用实时荧光定量PCR(qRT-PCR)和中性红染色试验,分别对不同品种百合初花期和盛花期花朵进行6个花香合成关键基因相对表达量和花香释放部位的测定.结果表明,4个百合品种初花期和盛花期共测定出61种挥发性化合物,盛花期花朵挥发物总含量均高于初花期,含量较高的成分有芳樟醇、(Z)-β-罗勒烯、桉树脑、(+)-柠檬烯、月桂烯、苯甲酸甲酯等.差异挥发物的筛选结果显示,4个品种共筛选出差异挥发物44种.将61种挥发性化合物分为9大类,4个品种初花期与盛花期花香的主要成分为萜烯类和酯类化合物. qRT-PCR结果表明,PAL、PAL3、DXS、TPS这4个基因在4个品种盛花期的相对表达量均高于初花期,而BSMT在‘西伯利亚’盛花期,DXR基因在‘竞争’和‘木门’盛花期的相对表达量低于初花期.中性红染色试验结果显示,盛花期花朵染色程度高于初花期,且均在花瓣的上半部反卷处染色最深,说明该部位为主要的花香物质释放区域.

Using headspace solid-phase microextraction(HS-SPME)combined with gas chromatographymass spectrometry(GC-MS),the floral volatile compounds of four lily(Lilium spp.)varieties at the early flowering stage and full blooming stage were analyzed.Quantitative real-time PCR(qRT-PCR)and neutral red staining experiments were employed to determine the relative expression levels of six key genes involved in floral scent synthesis and the scent-releasing sites in lily flowers during different stages.The results revealed that a total of 61volatile compounds were identified in the early flowering stage and full blooming stage of the four lily varieties.The total volatile compound contents were higher in the full blooming stage compared to the early flowering stage.The major components with higher contents included linalool,(Z)-β-ocimene,1,8-cinede,D-limonene myrcene,and methyl benzoate.Screening of differential volatile compounds identified 44 different compounds among the four varieties.The 61 volatile compounds were classified into nine major classes,the main volatile compounds of four varieties in early flowering stage and full blooming stage were terpenes and esters.The qRT-PCR results indicated that the relative expression levels of the PAL,PAL3,DXS,and TPS genes were higher in the full blooming stage compared to the early flowering stage in all four varieties.The relative expression levels of BSMT gene in full blooming stage of'Siberia'and DXR gene in full blooming stage of'Competition'and'Conca d'Or'were lower than those in early flowering stage.The neutral red staining experiment revealed that the degree of staining was higher in the full blooming stage,with the upper half of the petals showing the deepest staining,indicating that this area was the main site for the release of floral scent compounds.