烟草(Nicotiana tabacum)碳酸酐酶基因NtCA7的克隆及表达模式分析

Cloning and Expression Pattern Analysis of Carbonic Anhydrase Gene NtCA7 in Nicotiana tabacum

为了给烟草碳酸酐酶的功能研究提供理论依据,本研究采用同源克隆的方法,从普通烟草(Nicotiana tabaccum)中克隆得到一个属于α碳酸酐酶家族的烟草碳酸酐酶基因NtCA7。该基因CDS全长810 bp,编码了一个由270个氨基酸组成的蛋白。该蛋白分子量为31.03 kD,等电点为8.95,定位在细胞质基质中,属于亲水性蛋白,存在信号肽与磷酸位点。同源性分析结果显示,NtCA7基因与其它茄科植物的氨基酸序列相似度较高。NtCA7基因在烟草根、茎、叶、花中均有表达,其中,在叶中表达量最高。同时,NtCA7基因响应高盐、干旱、低钾、ABA、低温及H2O2的诱导表达。本研究结果表明,NtCA7基因可能在烟草非生物胁迫生理响应过程中发挥作用,对关于增强烟叶抗逆性,提高烟叶产质量的进一步研究有着重要意义。

In order to provide a theory evidence for the functional study of tobacco carbonic anhydrase,a tobacco carbonic anhydrase gene NtCA7 belonging toα-carbonic anhydrase family was cloned from common tobacco(Nicotiana tabaccum)by homologous cloning.The full CDS length of gene was 810 bp,encoding a protein consist of 270 amino acids.The protein has a molecular weight of 31.03 kD and an isoelectric point of 8.95.It was located in the cytoplasmic matrix and belong to hydrophilic protein,existed signal peptide and phosphoric acid sites.The results of homology analysis showed that NtCA7 gene has high similarity with amino acid sequences of other Solanaceae plants.NtCA7 gene was expressed in tobacco roots,stems,leaves and flowers,of which the highest expression was in leaves.At the same time,NtCA7 gene responded to the induced expression of high salt,drought,low potassium,ABA,low temperature and hydrogen peroxide.The results showed that NtCA7 gene may play a role in physiological response of abiotic stress in tobacco,which had great significance to further study on enhancing the resistance of tobacco leaves and improving the yield and quality of tobacco leaves.