Characterization of The Na~+/H~+ Antiporter in Tonoplast Vesicles From Populus tremula. calli
- VernacularTitle:欧洲山杨液泡膜Na~+/H~+反向运输体的性质鉴定
- Author:
Jingjing LIU
;
Xujia ZHANG
;
Cunfu LU
- Publication Type:Journal Article
- Keywords:
Populus tremula calli, Na+/H+ antiporter, V-ATPase
- From:
Progress in Biochemistry and Biophysics
2006;0(12):-
- CountryChina
- Language:Chinese
-
Abstract:
The Na+/H+ antiporter in vacuolar membranes transports Na+ from the cytoplasm to vacuoles using a pH gradient generated by proton pumps, which could reduce Na+ toxicity. It is uncertain that whether the woody plants have the same mechanism. Through differential centrifugation and sucrose density gradient centrifugation, tonoplast vesicles were isolated from Populus tremula calli broken by blender. After establishing pH gradient by V-ATPase, Na+ could dissipate the pH gradient, which indicates that there is Na+/H+ antiporter in the tonoplast vesicles from Populus tremula calli (Km=11.4 mmol/L). Amiloride could inhibit the Na+/H+ antiporter activity. The antiporter could transport Na+ and K+, the affinity for Na+ is higher. Salt stress decreased Km and Vmax.
