Abstract:

Using a cDNA fragment PCR amplified from Arabidopsis AtNHX1 as the probe, a novel vacuole Na⁺/H⁺ antiporter gene (OsANT1) in rice was obtained based on the screening of a cDNA library made from leaves of rice plants treated with 200 mmol L^-1 NaCl. The results indicated that the full-length of OsANT1 cDNA was 2 178 bp. The open reading frame (ORF) of OsANT1 was
1 608 bp with 535 translated amino acids. OsANT1 had 15 exons and 14 introns with a total length of 4 835 bp at the DNA level. It was found that OsANT1 contained 12 transmembrane domains and had high similarities with other vacuole Na⁺/H⁺ antiporters from plant species, such as Arabidopsis thaliana, Oryza sativa, Triticum aestivum, Zea mays, Hordeum vulgare, Iris lacteal, and Phragmites australis. The expression of OsANT1 in leaf, stem and root was all induced by NaCl and the expression levels were increased with the increase of NaCl concentration applied and the elongation of NaCl treatment time. Taken together, it is suggested that OsANT1 is functional for rice to withstand NaCl under salt stress.

Key words: Rice (Oryza sativa), OsANT1, Gene characterization, Gene expression