作 者：
魏小春;张晓辉;吴青君;王海平;沈镝;邱杨;宋江萍;李锡香
单 位：
农业部蔬菜作物基因资源与种质创制北京科学观测实验站;中国农业科学院蔬菜花卉研究所
关键词：
欧洲山芥;小菜蛾;皂苷;beta–香树脂合成酶;克隆;荧光定量RT-PCR;抗虫
摘 要：
以能够产生抗虫皂苷的高抗小菜蛾资源G型欧洲山芥(Barbarea vulgaris R.Br.)B44为材料,利用RACE技术克隆出皂苷合成关键酶beta–香树脂合成酶的基因(Barbarea vulgaris beta-amyrin synthase,Bv-beta-AS)。该基因编码区序列长为2289bp(GenBank登录号JQ172795),推导其编码762个氨基酸;在基因组水平上长度为4107bp(GenBank登录号JQ172796),含有15个内含子。Bv-beta-AS编码的氨基酸具有beta–香树脂合成酶基因家族的保守序列,即DCTAE序列和QW特征序列,氨基酸多序列比对和进化树分析表明,该基因与拟南芥beta–香树脂合成酶基因的相似性最高,为74%。利用荧光定量PCR对欧洲山芥在小菜蛾诱导下该基因的表达进行研究,结果表明,该基因受虫害诱导时上调表达,但是上升到12h达顶峰后随时间推移呈回归的趋势。从序列特征和表达模式上推测,Bv-beta-AS可能是抗虫皂苷合成途径的一个关键酶的基因。
译 名：
Cloning,Characterization and Real-time RT-PCR Analysis of a Key Gene beta-Amyrin synthase for Saponin Biosynthesis in Barbarea vulgaris
作 者：
WEI Xiao-chun,ZHANG Xiao-hui,WU Qing-jun,WANG Hai-ping,SHEN Di,QIU Yang,SONG Jiang-ping,and LI Xi-xiang(Institute of Vegetables and Flowers,China Academy of Agricultural Sciences,China Academy of Agricultural Sciences, Beijing Research Station of Vegetable Crop Gene Resource and Germplasm Enhancement Ministry of Agriculture,Beijing 100081,China)
关键词：
Barbarea vulgaris;Plutella xylostella;saponin;beta-amyrin synthase;cloning;real-time RT-PCR;insect resistant
摘 要：
G-type Barbarea vulgaris R.Br. which produce saponins is a rare insect resistant vegetable in Cruciferae. A beta-amyrin synthase gene which codes a key enzyme of saponin biosynthesis pathway was cloned from Barbarea vulgaris R.Br. using RT-PCR and RACE(Rapid Amplification of cDNA Ends) method,and named as Bv-beta-AS. The Bv-beta-AS contained a coding sequence of 2 289 bp(GenBank accession number:JQ172795),which encoded 762 amino acids. The gene of 4 107 bp from genomic DNA was further cloned,which contained 15 introns embedded in its coding sequences. The deduced protein of this gene contained the conserved characteristic motif of beta-amyrin synthase -DCTAE and QW. And thehigh similarity of this gene with the beta-amyrin synthase from other plants indicated it was a homologue of beta-amyrin synthase. Multiple sequence alignments and phylogenetic tree analyses showed that Bv-beta-AS was clustered with Arabidopsis beta-amyrin synthase and showed the highly similarity(74%) in amino acid sequences. The expression of Bv-beta-AS under the diamondback moth(Plutella xylostella) attack was determined by real-time RT-PCR. The results showed that Bv-beta-AS gene expression was up-regulated within 12 h of diamondback moth attack,but decline tendency appeared after 12 hours. Both the sequences analysis results and the real-time RT-PCR data indicated that Bv-beta-AS may be an important candidate gene of saponin biosynthesis pathway.
