Abstract:

H+ ATPase activity of tonoplast in roots of Hordeum vulgare L. cv.“Tanyin 2" (salt tolerant cultivar) increased when the roots were exposed to 50-200 mmol/L NaCl for 2 d, and decreased when NaCl concentration was increased to 600 mmol/L. In “Kepin 7" (salt sensitive cultivar), tonoplast H+ ATPase activity in roots also increased at lower levels of NaCl (50-100 mmol/L), but decreased at higher levels of NaCl (200-600 mmol/L). Tonoplast fluidity in roots of“Tanyin 2" decreased at 50-200 mmol/L NaCl, and increased significantly at 600 mmol/L NaCl. Under salt stress, the change of tonoplast fluidity was identical with that of the ratio of unsaturated fatty acids to saturated fatty acids in tonoplast lipid of barley roots. It is proposed that the increase of tonoplast fluidity due to increased degree of unsaturation of fatty acids is one of the reasons leading to the decrease of H+ ATPase activity under higher level of NaCl stress.

NaC1 胁迫下大麦根液泡膜H⁺-ATPase活性、离子吸收与钙的关系
章文华 刘友良
（南京农业大学农学院，农业部作物生长调控重点开放实验室，南京210095）

摘要：NaCl胁迫2d，耐盐大麦（Hordeum vulgare L.cv)（“滩引2号”）根系液泡膜H⁺-ATPase活性增强，H⁺-PPase活性下降。以质膜Ca ²⁺通道抑制剂La³⁺(1 mmol/L)或Ca ²⁺螯合剂EGTA（5mmol/L)处理大麦幼苗，抑制了NaCl诱导的液泡膜H⁺-ATPase活性的增强，但提高了H⁺-PPase活性；用CaM拮抗剂三氟拉嗪（TFP，20μmol/L）处理，也抑制了液泡膜H⁺-ATPase活性的增强。NaCl胁迫下，外加La³⁺，TFP或La ³⁺ ，TFP处理，使Na⁺ 吸收增加，K ⁺和Ca ²⁺ 吸收降低。结果表明，NaCl胁迫下，液泡膜H⁺ -ATPase活性提高和离子吸收的变化可能与Ca-CaM系统有关。

文章关键词: 液泡膜 质子泵 钙 离子吸收 耐盐性 大麦
 

Key words: salt stress, H+ ATPase, membrane fluidity, fatty acid composition, barley