Cloning, subcellular localization and expression pattern analysis of tobacco nitrate transporter NtNRT1.7 gene

In order to study the role of nitrate transporter (NRT) in the uptake and transport of nitrate in tobacco, a nitrate transporter gene encoding 612 amino acids with a total length of 1 839 bp was cloned using the cDNA of tobacco cultivar K326 as a template and named as NtNRT1.7. Bioinformatics analysis indicated that NtNRT1.7 had typical transmembrane domains. The homology analysis showed that the homology of NtNRT1.7 and Arabidopsis thaliana AtNRT1.7 was 57.23%. Subcellular localization results showed that this protein was located on the cell membrane and was a typical membrane protein. Promoter analysis and QRT-PCR results of different stress treatments indicated that NtNRT1.7 gene was highly expressed in mature leaves, its expression was suppressed by low nitrogen and enhanced by drought, low temperature, high salt and other stresses, which suggested that NtNRT1.7 gene might be involved in nitrate recycle under abiotic stresses.