Coordinate Up‏-‏regulation of Vacuolar Pyrophosphatase and V-Na+/H+ ‎Antiporter to Early Salt Stress in Halophytic Monocot ‎Leptochloa fusca Roots ‎

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Vacuolar H+-translocation pyrophosphatase (V-PPase) and Na+/H+ antiporter (V-Na+/H+) are important transporters in plant cells and have essential roles against abiotic stresses. In this study, the effects of salt stress were surveyed on the transcription of V-PPase pump and Na+/H+ antiporter genes at early times of NaCl treatment in roots of halophytic grass Leptochloa fusca through the Real Time PCR. The first results showed that L. fusca has high ability for accumulating Na+ under saline conditions. Real-Time PCR analysis demonstrated that the expression level of V-PPase and V-Na+/H+ increased in response to different levels of NaCl treatment, but the transcriptional increase of V-Na+/H+ gene was higher than that of the V-PPase gene, indicating that V-Na+/H+ had a crucial role in salt tolerance in this plant. These results indicated that coordinate up-regulations of V-PPase expression and Na+/H+ antiporter expression were correlated with Na+ sequestering into vacuoles of L. fusca. It was also shown that increase e in the expression level of V-Na+/H+ and V-PPase was correlated with the accumulation of sodium in roots, suggesting a physiological role for these antiporters and pump in Na+ compartmentation during adaptation to high salinity.