Abstract

Compartmentation of Na⁺ into vacuoles is an important way for cells to avoid the toxic effects of salt. Here, Arabidopsis AtCCX1 was studied in Pitch pastorisGS115. Yeast expressing AtCCX1 grew better in high H⁺ concentration medium and high salt medium than original strain and increased Na⁺ accumulation and decreased K⁺ accumulation. AtCCX1 was located in tonoplast in yeast. Transport essays were indicated by fluorescence SBFI and PBFI, respectively. Results show that AtCCX1 simultaneously participate in transports both of Na⁺ and K⁺ and the process was inhibited by H⁺-ATPase inhibitor vanadate. In conclusion, we suggest that AtCCX1 is an H⁺-dependent Na⁺/K⁺ exchanger.

Key words: AtCCX1, SBFI, PBFI, Na⁺ accumulation, K⁺ accumulation.

Abbreviation

[K⁺], K⁺ Concentration; [K⁺]m, K⁺ concentration in medium; [K⁺]c,K⁺ content in yeast cells; [Na⁺], Na⁺ concentration; [Na⁺]m, Na⁺ concentration in medium; [Na⁺]c, Na⁺ content in yeast cells; GAtCCX1, the Pitch pastoris GS115 expressing AtCCX1; T[Control], the Pitch pastoris GS115; [H⁺]m, H⁺concentration in culture media