摘要
为探讨乌龙茶加工过程中做青工序的机械力对香气成分中α-法呢烯的影响及形成机理,本实验以乌龙茶品种黄旦的鲜叶、萎凋叶、摇青叶为供试材料,未摇青等时间摊放叶为对照组,采用GC-TOF-MS方法检测乌龙茶加工过程中α-法呢烯含量,结合转录组和茶树基因组数据库筛选α-法呢烯合成酶(AFS)关键基因,构建系统进化发育树,利用实时荧光定量PCR(Quantitative Real-time PCR,qRT-PCR)进行数据验证,并进行α-法呢烯含量与基因表达水平间的相关性分析。结果表明,α-法呢烯的含量在第一次摇青时有所下降,由于机械胁迫的累加,摇青叶中α-法呢烯的含量逐渐增加并在第三次摇青时达到峰值(0.9485%)。筛选获得的CL11384.Contig7_All转录本与茶树α-法呢烯合成酶基因(CsAFS,GenBank登录号:MH125264.1)高度相似,暂命名为CsAFS7基因,该基因表达模式与测序数据相一致。皮尔逊相关系数分析表明,乌龙茶加工过程中α-法呢烯含量与CsAFS7基因的相关表达水平之间存在极显著正相关(r=0.951,P<0.01)。因此,乌龙茶做青过程中α-法呢烯的累积可能受到CsAFS7基因的表达调控。
For purpose of understanding the influence of mechanical force during the turning-over process on the formation ofα-farnesene,in this experiment,fresh tea leaves,solar withering tea leaves,turned-over tea leaves of the oolong tea cultivar Camellia sinensis cv.Huangdan as test materials and spread tea leaves(collected at the same time point)as control group were detected by headspace-gas chromatograpy-mass spectrometry(GC-TOF-MS).Thereafter,α-farnesene synthase(AFS)gene was selected based on Tea Tree Genemo Database and phylogenetic tree was constructed.The data were measured by quantitative real-time PCR and the relative correlation betweenα-farnesene content and relative gene expression level was also analyzed.The results indicated that although theα-farnesene content in first-time turned-over leaves decreased under the mechanical force,it still increased gradually with the treatments and reached the peak at the third-time turned-over point(0.9485%).The CL11384.Contig7_All gene was remarkably similar to CsAFS(GenBank accession no.MH125264.1),so CL11384.Contig7_All gene was named as CsAFS7 tentatively since the gene expression pattern was corresponding with the sequencing data.The correlation betweenα-farnesene content of manufacturing-process oolong tea and relative expression level of CsAFS7 gene were evaluated by Pearson correlation coefficient,and the results showed that there was a significant positive correlation(r=0.951,P<0.01).To sum up,the accumulation ofα-farnesene content during manufacturing process might be regulated by CsAFS7 gene expression manipulation.
作者
吴晴阳
周子维
武清扬
倪子鑫
赖钟雄
孙云
WU Qing-yang;ZHOU ZI-wei;WU Qing-yang;NI Zi-xin;LAI Zhong-xiong;SUN Yun(College of Horticulture,Fujian Agriculture and Forestry University/Key Laboratory of Tea Science of Fujian Universities,Fuzhou 350002,China;Institute of Horticulture Biotechnology,Fujian Agriculture and Forestry University,Fuzhou 350002,China)
出处
《食品工业科技》
CAS
北大核心
2020年第15期135-142,共8页
Science and Technology of Food Industry
基金
国家现代农业(茶叶)产业技术体系建设专项(CARS-19)
福建农林大学科技创新基金项目(CXCX2017178)
福建农林大学科技创新专项(CXZX2018076)。
