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The chenopodiaceae Suaeda salsaL. is a leaf succulent euhalophyte. Shoots of the S. salsaare larger and more succulent when grown in highly saline environments. This increased growth and water uptake has been correlated with a large and specific cellular accumulation of sodium. S. salsadoes not have salt glands or salt bladders on its leaves. Thus, this plant must compartmentalize the toxic Na+in the vacuoles. The ability to compartmentalize sodium may result from a stimulation of the proton pumps that provide the driving force for increased sodium transport into the vacuole. In this work, we isolated the cDNA of the vacuolar membrane proton-translocating inorganic pyrophosphatase (H+-PPase) from S. salsa. The SsVPcDNA contains an uninterrupted open reading frame of 2292 bp, coding for a polypeptide of 764 amino acids. Northern blotting analysis showed that SsVPwas induced in salinity treated leaves. The activities of both the V-ATPase and the V-PPase in Arabidopsisoverexpressing SsVP-2 is higher markedly than in wild-type plant under 200 mM NaCl and drought stresses. The Overexpression of SsVPcan increase salt and drought tolerance of transgenic Arabidopsis.The chenopodiaceae Suaeda salsaL. is a leaf succulent euhalophyte. Shoots of the S. salsaare larger and more succulent when grown in highly saline environments. This increased growth and water uptake has been correlated with a large and specific cellular accumulation of sodium. S. salsadoes not have salt glands or salt bladders on its leaves. Thus, this plant must compartmentalize the toxic Na+in the vacuoles. The ability to compartmentalize sodium may result from a stimulation of the proton pumps that provide the driving force for increased sodium transport into the vacuole. In this work, we isolated the cDNA of the vacuolar membrane proton-translocating inorganic pyrophosphatase (H+-PPase) from S. salsa. The SsVPcDNA contains an uninterrupted open reading frame of 2292 bp, coding for a polypeptide of 764 amino acids. Northern blotting analysis showed that SsVPwas induced in salinity treated leaves. The activities of both the V-ATPase and the V-PPase in Arabidopsisoverexpressing SsVP-2 is higher markedly than in wild-type plant under 200 mM NaCl and drought stresses. The Overexpression of SsVPcan increase salt and drought tolerance of transgenic Arabidopsis.