Cloning and sequence analysis of gene encoding plasma aquaporin of Tamarix albiflonum

Abstract

Plant aquaporins are water-selected-channels in plants and are involved in seed germination, cell elongation, stoma movement, fertilization and so on. Some plant aquaporins also play an important role in drought stress response. In this paper, the gene encoding the Tamarix albiflonum Aquaporin (AQP) was amplified by 5´rapid amplification of cDNA end (RACE) on the basis of the sequence information obtained from the expressed sequence tag of the subtractive hybridization library constructed under PEG6000 stress. The cDNA of the T. albiflonum AQP gene is 1,043 bp long, encoding a protein of 287 amino acids with a predicted molecular mass of 30.9 kDa, has 6 transmembrane regions, and possessing the major intrinsic protein (MIP) family signal consensus sequence SGXHXNPAVT and the higher plant plasma membrane intrinsic protein (PIP) highly conservative sequence GGGANXXXXGY and TGI/TNPARSL /FGAA I/VI/VF/YN. A comparative molecular analysis of the nucleotides equence in National Center for Biotechnology Information (NCBI) databases showed that it shared 95% homology with the gene of Arabidopsis thaliana (MIP-C), with a theoretical isoelectric point 8.84.