三种锦鸡儿属植物过氧化氢酶基因的克隆及表达特性分析

Cloning and Expression Analysis of Catalase Genes from Three Caragana Species

为研究过氧化氢酶基因在锦鸡儿属植物抵御干旱胁迫中发挥的作用,采用兼并PCR(degenerate polymerase chain reaction,Deg-PCR)和末端克隆(rapid amplify cDNA ends,RACE)技术分离了柠条锦鸡儿(Caragana korshinskiikom)、小叶锦鸡儿(C.microphylla)和中间锦鸡儿(C.davazamcii)的过氧化氢酶(Catalase,CAT)基因cDNA序列,并对它们在干旱胁迫条件下的表达特性进行了比较分析。这3种锦鸡儿属植物CAT cDNA均为1755 bp,含有1个1479 bp的开放阅读框(open reading frame,ORF)、85个碱基的5’非编码区和201个碱基的3’非编码区,编码492个氨基酸的蛋白质。序列比较分析发现,该3条序列仅在322 bp处有一个碱基的差异(CkCAT为T碱基,CmCAT和CdCAT为C碱基),但它们编码相同的氨基酸。生物信息学分析显示,CkCAT、CmCAT和CiCAT的与其他植物的CAT蛋白具有较高的同源性,在进化上与豇豆和大豆的CAT亲缘关系较近。实时荧光定量PCR分析结果显示,在干旱胁迫条件下CkCAT、CmCAT和CdCAT的表达量明显升高,显示CAT在锦鸡儿属植物抵御干旱逆境中发挥重要作用。

For understanding the function of Catalase(CAT)genes of Caragana plants in resisting drought stress,the full-length sequences of CAT cDNAs were isolated from Caragana korshinskiikom,C.microphyll and C.intermedia using degenerate-PCR and RACE technique,and their expression under drought stress conditions were analyzed.The CAT cDNA sequences contain 1755 bp,including a predicted ORF of 1479 bp,a 5'-untranslated region of 85 base,and a 3'-untranslated region of 201 base,encode a polypeptide of 492 amino acids.Sequence comparative analysis indicated there is a different nucleotide in 322 bp among CkCAT,CmCAT and CdCAT,however they encode the same amino acid.Bioinformatic analysis showed that the Caragana CATs share high identity and similarity to those from the other plants,which is close relatives to CATs from Vigna radiate and Glycine.Real-time PCR detection revealed that the expression of the Caragana CATs were strongly induced under drought stress conditions,showing that the CAT plays an important role in resisting to drought stress in the Caragana plants.