4个不同苯甲醇含量茶树品种的转录组分析

Transcriptome Analysis in Four Tea Cultivars of Different Benzyl Alcohol Content

香气是茶叶品质决定因子之一,苯甲醇作为一种芳香族醇,参与茶叶香气物质形成。本研究选用4个苯甲醇含量不同的茶树品种,分别是‘薮北’(苯甲醇含量低)、‘湘妃翠’、‘牛皮茶’(苯甲醇含量中等)和‘铁香茗’(苯甲醇含量高),通过Illumina Hiseq^TM2000高通量测序技术对上述4种茶树一芽二叶的转录组进行测序,通过Blast搜索比对,共有151 198条Unigene获得了基因注释。4种茶树在新陈代谢路径中注释的基因数最多,其中次生代谢物生物合成和萜类和聚酮化合物代谢途径可能与茶树苯甲醇合成有关,通过对4种茶树样品的Unigene与NR数据库比对,发现5条可能编码茶树苯甲醇合成途径的关键酶β-葡萄糖苷酶基因,这些相关研究为分析茶树香气功能基因提供理论指导,为香气相关候选基因的发掘提供重要依据。

Aroma is one of th e determinants of tea quality and benzyl alcohol participates in the formation of aroma as an aromatic alcohol. This research selected four tea cultivars of different benzyl alcohol contents:’Soubei’(low benzyl alcohol content),’Xiangfeicui’,’Niupicha’(medium benzyl alcohol content), and ’Tiexiangming’(high benzyl alcohol content). Through the Illumina HiseqTM2000 high-throughput sequencing technology, transcriptome sequencing was applied to bud and two leaves of four tea cultivars above. A total of 151 198 Unigenes were annotated through blast searching comparison. The highest number of genes annotated of the four tea trees was in the metabolic pathways, and secondary metabolite biosynthesis and terpene and polyketide metabolic pathways might be related to the synthesis of benzyl alcohol in tea trees. By comparing the Unigene and NR databases of four tea tree samples, there showed 5 key enzyme β-glucosidase genes that likely encode in the benzyl alcohol pathway of tea tree. These related studies would lay a good foundation for the analysis of tea aroma functional genes and provide an important basic for the discovery of related candidate genes of aroma.