The cotton GhNHX1 gene encoding a novel putative tonoplast Na(+)/H(+) antiporter plays an important role in salt stress.
A cDNA clone was isolated from cotton (Gossypium hirsutum) cDNA library and characterized with regard to its sequence, regulation in response to salt stress and functions in yeast mutants and transgenic tobacco plants. The clone, designated as GhNHX1, contains 2485 nucleotides with an open reading frame of 1629 nucleotides, and the deduced amino acid sequence showed high identities with other plant vacuolar-type Na(+)/H(+) antiporters. Northern blot analysis indicated that the mRNA accumulation of GhNHX1 was strongly induced by salt stress and abscisic acid in cotton seedlings. The expression of GhNHX1 in yeast Na(+)/H(+) antiporter mutant showed function complementation. The transgenic tobacco plants overexpressing GhNHX1 also had higher salt tolerance than the wild-type plants. The salt-induced mRNA level of GhNHX1 was 3 and 7 times higher in the salt-tolerant cotton cultivar ZM3 than those in the salt-sensitive cotton cultivars ZMS17 and ZMS12, respectively. Together, these results suggest that the products of the novel gene, GhNHX1, function as a tonoplast Na(+)/H(+) antiporter and play an important role in salt tolerance of cotton.
Wu
Chang-Ai
CA
Department of Biochemistry and Molecular Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, P.R. China.
Yang
Guo-Dong
GD
Meng
Qing-Wei
QW
Zheng
Cheng-Chao
CC
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D003368:Gossypium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000633:toxicity*; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics* / Q000302:isolation & purification
D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride; D000040:Abscisic Acid