烟草3个甜菜碱醛脱氢酶基因的克隆及序列分析

Cloning and Sequence Analysis of Three Betaine Aldehyde Dehydrogenase Genes in Tobacco (Nicotiana tabacum)

为从烟草中克隆到与植物抗逆相关的甜菜碱醛脱氢酶(EADH)基因,以枸杞BADH基因为探针,通过电子克隆的方法从烟草栽培品种K326中克隆到3个BADH基因(NtBADH1、NtBADH2、NtBADH3),并对其进行了序列分析。结果表明:3个BADH基因的cDNA序列均包含完整的开放读码框,分别编码504个氨基酸,具有醛脱氢酶家族高度保守的十肽(VTLELGGKSP)以及与酶功能有关的半胱氨酸残基(C)。烟草3个BADH与其他物种在蛋白质水平上表现较高的相似性,NtBADH1和NtBADH2在进化上与同科的番茄BADH蛋白距离较近,NtBADH3在进化上与同科的枸杞BADH蛋白距离较近。这些结果为进一步分析该类蛋白的性质和功能,并为植物抗逆基因工程研究提供了基础资料。

In silicon cloning,three betaine aldehyde dehydrogenase genes（NtBADH1,NtBADH2 and NtBADH3） were obtained successfully from tobacco cultivar K326 by using the wolfberry BADH gene sequence（FJ514799） to be probe.Sequence analysis showed that the in silicon cloned cDNAs had a complete open reading frame（ORF） and encoded 504 amino acid residues,respectively,including the conserved decapaptide（VTLELGGKSP） and cysteine residue（C） in aldehyde dehydrogenase（ALDHs）.The three tobacco BADH genes showed high similarity at the protein level with that of other species.Phylogenetic tree analysis showed that NtBADH1 and NtBADH2 had closest relationship with that from Solanum lycopersicum,and NtBADH3 had closest relationship with that from Lycium barbarum.Those results is of potential importance not only for further study on the nature and function of tobacco BADHs but also for the improvement of crops for abiotic stress resistance by genetic engineering.