目的克隆狭叶松果菊Echinacea angustifolia 3-脱氢奎尼酸合成酶基因并考察其在各个组织中的表达情况。方法采用快速扩增cDNA末端技术,以狭叶松果菊组培苗cDNA为模板,克隆出狭叶松果菊3-脱氢奎尼酸合成酶基因全长序列并通过半定量RT-PCR分析其在不同器官中的表达模式。结果克隆到的基因(命名为EanaroB)全长为1 424 bp,编码一个442个氨基酸残基组成的多肽。其氨基酸序列与植物来源的3-脱氢奎尼酸合成酶同源性都在80%左右。将得到的序列提交Genbank,序列号为EU293857。半定量RT-PCR结果表明,狭叶松果菊EanaroB基因在狭叶松果菊的根、茎、叶、花中均有表达,但花和叶中的表达量较高,在根和茎中较少。结论采用RACE和PCR的方法从狭叶松果菊中克隆出了咖啡酸类化合物生物合成途径上的一个基因EanaroB,为进一步研究咖啡酸类衍生物生物合成代谢途径提供一定依据,为今后利用基因工程技术提高咖啡酸类衍生物,包括苯乙醇苷类物质松果菊苷的代谢工程打下一定基础。

Objective To clone 3-dehydroquinate synthase cDNA from Echinacea angustifolia and in-vestigate its tissue expression characteristics in various tissues. Methods By using homology cloning andRACE-PCR，the cDNA encoding 3-dehydroquinate synthase was amplified with cDNA library of culturedplantlets as the template. The specificity expression profile in different tissues including roots，stems，leaves，and flowers of E. aungustifolia was investigated by semi-quantitative RT-PCR as well. Results The full length cDNA of 3-dehydroquinate synthase (named as EanaroB) had 1 424 by with an open read-ing frame encoding 442 amino acids of protein and its EanaroB was around 80%homologous with the se-quences of 3-dehydroquinate synthase from other plants. The sequence was reported to the GeneBank andcoded as EU293857. The results of semi-quantitative RT-PCR indicated that the expression of EanaroBwas detected in different tissues，while only the expression in leaves and flowers reached to a high level. Conclusion The cDNA encoding EU293857 from E. angusti folia is cloned and reported. This work un-derlays the first step for exploring the pathway of caffeic acid derivatives biosynthesis and improving thecontent of caffeic acid derivatives including phenylethanoid glycosides.