Molecular characterization of PeSOS1: the putative Na(+)/H (+) antiporter of Populus euphratica.
Populus euphratica is a salt-tolerant tree species growing in semi-arid saline areas. A Na(+)/H(+) antiporter gene was successfully isolated from this species through RACE cloning, and named PeSOS1. The isolated cDNA was 3665 bp long and contained a 3438 bp open reading frame that was predicted to encode a 127-kDa protein with 12 hypothetical transmembrane domains in the N-terminal part and a long hydrophilic cytoplasmic tail in the C-terminal part. The amino acid sequence of this PeSOS1 gene showed 64% identity with the previously isolated SOS1 gene from the glycophyte Arabidopsis thaliana. The level of protein expressed by PeSOS1 in the leaves of P. euphratica was significantly up-regulated in the presence of high (200 mM) concentrations of NaCl, while the mRNA level in the leaves remained relatively constant. Immunoanalysis suggested that the protein encoded by PeSOS1 is localized in the plasma membrane. Expression of PeSOS1 partially suppressed the salt sensitive phenotypes of the EP432 bacterial strain, which lacks the activity of the two Na(+)/H(+) antiporters EcNhaA and EcNhaB. These results suggest that PeSOS1 may play an essential role in the salt tolerance of P. euphratica and may be useful for improving salt tolerance in other tree species.
Wu
Yuxia
Y
Cold and Arid Regions Environment and Engineering Research Institute, The Chinese Academy of Sciences, Lanzhou, PR China.
Ding
Nan
N
Zhao
Xin
X
Zhao
Mingui
M
Chang
Zongqiang
Z
Liu
Jianquan
J
Zhang
Lixin
L
D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D057927:Hydrophobic and Hydrophilic Interactions; D050296:Microbial Viability / Q000187:drug effects; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D032107:Populus / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D010940:Plant Proteins; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride