盐胁迫下巴西蕉幼苗部分细胞膜系统Ca^(2+)-ATPase的活性变化

Changes of Ca^(2+)-ATPase activities of part of cell membrane system in Brazilian banana seedling under salt stress

为研究盐胁迫下微粒体膜Ca^(2+)-ATPase活性变化,试验采用营养液培养的方法,研究巴西蕉幼苗在60 mmol·L^(-1)的NaCl胁迫4、8、12、24和48 h下,增加外源CaCl_2和钙离子螯合剂EGTA处理,测定其叶片和根部分细胞膜上的Ca^(2+)-ATPase活性。结果表明,巴西蕉幼苗根和叶片的质膜、液泡膜及内质网膜的Ca^(2+)-ATPase活性各不同,且CaCl_2处理的Ca^(2+)-ATPase活性均显著高于其它3种处理。在NaCl胁迫4 h时,CaCl_2处理的Ca^(2+)-ATPase活性均显著升高,而EGTA处理的则显著下降。幼苗质膜和液泡膜的Ca^(2+)-ATPase活性远远大于内质网膜Ca^(2+)-ATPase。这表明了质膜和液泡膜Ca^(2+)-ATPase活性主要参与巴西蕉幼苗Ca^(2+)稳态的调控。

To study the changes in Ca2＋-ATPase activities of microsome membrane under salt stress, the Brazilian banana seedlings were treated with the exogenous CaCl2 and Ca2＋ chelating agent EGTA under 60 mmol·L-1 NaCl for 4, 8, 12, 24 and 48 h, and Ca2＋-ATPase activities of part of cell membrane in leaves and roots were determined. The results showed that Ca2＋-ATPase activities of plasma membrane, tonoplast membrane and endoplasmic reticulum membrane in roots and leaves were different, and the Ca2＋-ATPase activity with CaCl2 treatment was significantly higher than those of other three treatment. Under NaCl stress for 4 h, the Ca2＋-ATPase activities with CaCl2 treatment were significantly increased, while the Ca2＋-ATPase activities with EGTA treatment decreased significantly. The Ca2＋-ATPase activities of the plasma membrane and tonoplast membrane were much larger than that of the endoplasmic reticulum membrane. These indicated that Ca2＋-ATPase activity of plasma membrane and tonoplast membrane mainly involved in the regulation of Ca2＋ homeostasis in Brazilian banana seedlings.