普通烟草NtNDPK4基因的克隆与表达分析

为揭示核苷二磷酸激酶在烟草中的功能和作用机制，从烟草K326克隆获得了1个核苷二磷酸激酶基因并命名为NtNDPK4,CDS长度为678 bp，编码225个氨基酸。生物信息学分析表明，NtNDPK4蛋白分子量大小24.95 kDa,pI约8.34，亚细胞定位预测在叶绿体上，进化分析显示该蛋白属于NDPKⅡ型，顺式作用元件分析预测该基因启动子含有激素和光照响应的作用元件。组织表达特异性分析结果显示，NtNDPK4在烟草各组织中均有表达。在MeJA、ABA、GR-24、IAA、GA和6-BA等激素处理下，NtNDPK4基因的表达显著上调，尤其是GA处理后NtNDPK4基因表达上调了近50倍。黑暗生长的烟草幼苗恢复光照24 h后，NtNDPK4基因表达明显上调。这表明烟草NtNDPK4基因可能参与激素和光照响应。

Cloning and expression analysis of NtNDPK4 gene in Nicotiana tabacum

In order to reveal the function and mechanism of nucleoside diphosphate kinase in tobacco, NtNDPK4 was cloned from tobacco cv. K326. The CDS length of NtNDPK4 was 678 bp, and 225 amino acids were encoded. Bioinformatics analysis showed that the molecular weight of NtNDPK4 protein was 24.95 kDa, and the pI was about 8.34. The subcellular localization was predicted in chloroplast. The evolutionary analysis showed that NtNDPK4 belonged to NDPK Ⅱ. The cis-acting element analysis predicted that the promoter of NtNDPK4 contained hormone and light-responsive elements. Tissue expression specificity analysis showed that NtNDPK4 was expressed in all tissues. Under the treatment of different hormones(MeJA, ABA, GR-24, IAA, GA and 6-BA), the expression of NtNDPK4 was significantly up-regulated, and the expression level of NtNDPK4 was up-regulated nearly 50 folds after the GA treatment. After 24 h of light restoration, the expression of NtNDPK4 in tobacco seedlings grown in darkness was also up-regulated obviously. These results suggest that NtNDPK4 might be involved in hormone and light responses.