Relationship Between Tonoplast H~+-ATPase Activity, Ion Uptake and Calcium in Barley Roots Under NaCl Stress

摘要

Under NaCl stress for 2 d, H~+-ATPase activity increased, and H~+-PPase activity decreased in the tonoplast of salt-tolerant barley (Hordeum vulgare L. cv. "Tanyin 2") roots. La~(3+) (1 mmol/L), an inhibitor of Ca~(2+) channel in plasma membrane, and EGTA (5 mmol/L), a Ca~(2+) chelator, inhibited this NaCl-induced increase in H~+-ATPase activity but stimulated the H~+-PPase activity. Treatment of barley roots with CaM antagonist (trifluoperazine, TFP, 20 μmol/L) also diminished the increase of H~+-ATPase activity induced by NaCl. La~(3+), TFP or La~(3+) + TFP increased Na~+ uptake and decreased K~+ and Ca~(2+) uptake in barley roots under NaCl stress. These results suggested that the activation of tonoplast H~+-ATPase and the regulation of Na~+ and K~+ uptake under NaCl stress may be related to Ca~(2+)-CaM system.