Molecular characterization of putative vacuolar NHX-type Na(+)/H(+) exchanger genes from the salt-resistant tree Populus euphratica.
The vacuolar NHX-type Na(+)/H(+) exchangers play a key role in salt tolerance in plants. However, little is known about the Na(+)/H(+) exchangers in the salt-resistant tree, Populus euphratica. In this study, we identified six putative vacuolar Na(+)/H(+) exchanger genes from P. euphratica, designated as PeNHX1-6. Real-time polymerase chain reaction indicated that the PeNHX1/3/6 transcripts were abundant compared with the other three PeNHX genes in the three tissues (roots, stems and leaves) examined. After NaCl treatment for 6 h, the transcript levels of PeNHX1-6 were upregulated in the roots. To address the function of PeNHX1-6, complementation studies were performed with the salt-sensitive yeast mutant strain R100, which lacks activity of the endosomal Na(+)/H(+) antiporter NHX1. The results showed that PeNHX1-6 compensates, at least in part, for the function of yeast NHX1. Moreover, PeNHX3 was targeted to the tonoplast when transiently expressed in onion. Together, these results suggest that PeNHX1-6 function as vacuolar Na(+)/H(+) exchangers and that PeNHX products play an important role in the salt resistance of P. euphratica.
Ye
Chu-Yu
CY
National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China.
Zhang
He-Chen
HC
Chen
Jin-Huan
JH
Xia
Xin-Li
XL
Yin
Wei-Lun
WL
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D005810:Multigene Family; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D055051:Salt-Tolerant Plants / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics* / Q000378:metabolism; D014617:Vacuoles / Q000235:genetics* / Q000378:metabolism
D018744:DNA, Plant; D010940:Plant Proteins; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride