Cloning and sequence analysis of a plasma membrane Na╋/H╋ antiporter fragment from halophyte Suaeda salsa

To investigate longdistance transport of Na+ in Suaeda salsa, degenerate primers were designed based on the conserved sequences of the SOS1 genes from other plants. Total RNA was extracted from the roots of S. salsa and the SOS1 gene fragment was obtained by reverse transcription polymerase chain reaction (RTPCR) aiming to provide the foundation for cloning fulllength SOS1 gene and expression regulation. The sequencing result showed that the SOS1 gene fragment (736 bp) from S. salsa encoded 224 amino acids. Homology comparison showed that the SOS1 gene fragment shared over 74% nucleotide and 61% amino acid similarity to SOS1 fragments from other plants.