论文部分内容阅读
黄花蒿中含有大量的香气类物质,在食品和医药行业有广泛的应用前景,但对其生物合成的分子机理研究非常欠缺.本研究采用SMART-RACE-PCR技术从黄花蒿花组织差异文库中获得了1个新的双键还原酶编码基因A aDBR3,其cDNA序列全长为1 279 bp,开放阅读框(ORF)长度为1 038 bp编码345氨基酸,蛋白分子量为38.46 kD,等电点(pI)为6.05.通过生物信息学的分析,AaDBR3属于中链脱氢酶超级家族中leukotriene B4 dehydrogenases类酶.系统发育进化树结果表明,该基因与烟草的烯丙醇脱氢酶(NtADH,GenBank:BAA89423.1)的同源性最高,相似性为77％.体外酶研究发现,重组蛋白酶能催化3-壬烯-2-酮向2-壬酮的转化,表明其属于双键还原酶.本研究为进一步丰富黄花蒿优异基因资源,及黄花蒿的品种改良提供了重要的靶基因.“,”A rtemisia annua contains a large amount of aroma compounds,which has a wide range of potential applications in the food and pharmaceutical industry,but the molecular mechanism of biosynthesis is poorly understood.In this study,a novel double bond reductase gene A aDBR3 was obtained from the differentially expressed gene library established using flowers of A.annua by SMART-RACE-PCR.The full-length cDNA of A aDBR3 was 1 279 bp,with a open read frame (ORF) of 1 038 bp,encoding 345 amino acid.The molecular weight of the protein was 38.46 kD,and the pI was 6.05.The bioinformatic analysis indicated that AaDBR3 belonged to leukotriene B4 dehydrogenases in the super family of medium chain dehydrogenase.The result of phylogenetic tree analysis showed this gene had the highest homology with allyl-alcohol dehydrogenase (NtADH,GenBank:BAA89423.1) in tobacco,and the similarity reached 77％.In vitro enzyme study found that recombinant protease could catalyze the conversion of 3-nonen-2-ketone to 2-nonanone,indicating that it belonged to double bond reductase.This study provided important target genes for further enriching the excellent gene resources of A rtemisia annua and improving the variety ofA rtemisia annua.