leaf tonoplast V-H+ -ATPase activity of a C3 halophyte Suaeda salsa is enhanced by salt stress in a Ca-dependent mode

• Published in: Journal of plant physiology 2005-03, Vol.162 (3), p.267-274
• Main Authors: Han, N, Shao, Q, Lu, C.M, Wang, B.S
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blotting, Western; C3 plants; calcium; Calcium - pharmacology; Cell physiology; Chenopodiaceae - enzymology; enzyme activity; Fundamental and applied biological sciences. Psychology; Germination; H-transporting ATPase; halophytes; Kinetics; membrane permeability; nutrient solutions; Plant Leaves - enzymology; Plant physiology and development; plant proteins; plant response; plasma membrane; Plasma membrane and permeation; potassium; salt stress; salt tolerance; seedling growth; seedlings; Seeds; sodium; sodium chloride; Suaeda; Suaeda salsa; tonoplast; vacular proton-translocating ATPase; Vacuolar Proton-Translocating ATPases - metabolism
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2004.07.016

Suaeda salsa seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of Ca(2+) (0 and 20 mmol/L) to study the effect of Ca(2+) nutrition on the growth and activity of leaf tonoplast V-H(+)-ATPase. Increase of Ca(2+) concentration in the solution markedly increased the relative growth quantity of S. salsa seedlings and Ca(2+) and K(+) concentration in the leaf cell sap under NaCl stress. The leaf V-H(+)-ATPase activity was significantly increased with increasing NaCl concentration under high Ca(2+) application (20 mmol/L), but little changed under Ca(2+) starvation (0 mmol/L). Western blot analysis showed that the leaf V-H(+)-ATPase of S. salsa was at least composed of A, B, D and c subunits, and their protein amounts were not affected by NaCl treatments under Ca(2+) starvation (0 mmol/L) with an exception of 100 mmol/L NaCl, but increased under high Ca(2+) application (20 mmol/L). There was a positive correlation between activity of V-H(+)-ATPase and the protein amounts of the subunits. The results suggest that Ca(2+) nutrition played an important role in the salt tolerance of S. salsa, and that enhancement of V-H(+)-ATPase activity under salt stress was Ca(2+)-dependent.