The Cloning And Sequence Analysis Of Full-length CDNA Of Plasma Membrane Aquaporin Genes From Stipa Grandis

Aquaporin represent an important selective pathway for water to move across cellular membrane, and involved in seed germination,cell elongation,stomatal movement,fertilization, and even some plant aquaporin that play an important role in response to stress. A typical grassland plants, Stipa grandis P.Smirn, growing in the steppe region of central Asia was collected and cultured. Full-length cDNA sequence of plasma membrane aquaporin genes from Stipa grandis was acquired by RT-PCR and RACE technology. Their structure of sequence of nucleotide and amino acid were analyzed by bioinformatics software. The mainly results as follows:The experiment obtained a total of nine core fragment cDNA sequences of SgPIPs, twenty-two 3′end cDNA sequences of SgPIPs, nine 5′end cDNA sequences of SgPIPs. The experiment cloned three full-length cDNA sequences of SgPIPs, named SgPIP1-1, SgPIP1-2 and SgPIP1-3.SgPIP1-1 full-length cDNA sequence consists of 991bp, which includes the length of 15bp of the 5′untranslated region, followed by 870bp of the open reading frame encoding 289 amino acids, and finally a 106bp of 3′untranslated region. SgPIP1-2 full-length cDNA sequence consists of 1248bp, which includes the length of 15bp of the 5′untranslated region, followed by 870bp of the open reading frame encoding 289 amino acids, and finally a 363bp of 3′untranslated region. SgPIP1-3 full-length cDNA sequence consists of 1068bp, which includes the length of 58bp of the 5′untranslated region, followed by 867bp of the open reading frame encoding 288 amino acids, and finally a 143bp of 3′untranslated region.SgPIP1-1, SgPIP1-2, and SgPIP1-3 amino acid sequence analysis showed that their not only have the MIP family of signal sequence SGXHXNPAVT, but also the characteristics of plasma membrane water channel protein signal sequence GGGANXXXXGY and TGI/TNPARSI/FGAAI/VI/VF/YN. Besides their have the typical six transmembrane domains and two NPA units.phylogenetic tree constructed by nucleotide sequences Between SgPIP1-1, SgPIP1-2, and SgPIP1-3 and gramineous species which are very closer in relationship showed that SgPIP1-1 and SgPIP1-3 the most closest in evolution, and then with Zea mays,Saccharum officinarum,Oryza sative clustered together. SgPIP1-2, Hordeum vulgare, and Triticum aestivum have the closest relationship in evolution. Phylogenetic tree constructed by amino acids sequences between SgPIP1-1, SgPIP1-2, and SgPIP1-3 and all PIPs of barley showed that SgPIP1-1, SgPIP1-2, and SgPIP1-3 were PIP1 subfamily members.