摘要
冷和盐预处理显著提高水稻（OryzasatwaL．）幼苗的抗寒性，但两预处理诱导提高的抗寒性可为钙的螫合剂EGTA和钙调素的抑制剂CPZ所抑制。冷预处理有提高很质膜、液泡膜和叶片的叶绿体Ca2+．ATPase活性和质膜Fe（CN）3-6还原活性的作用，其中对提高根质膜Ca2+－ATPase活性和Fe（CN）3-6还原活性的作用尤为显著。盐预处理对提高根质膜、幼叶叶绿体Ca2+ATP酶活性和质膜Fe（CN）3-6还原活性的作用类似于冷预处理。虽然盐预处理苗液泡膜Ca2+－ATPase活性有所下降，但其活性仍明显高于未预处理苗，表明在低温胁迫下，两预处理苗都有较强的维持Ca2+稳态能力。结果揭示，冷和盐预处理诱导水稻幼苗抗寒性的提高，可能均与在低温胁迫下两预处理能有效地维持或激活Ca@+－ATPase活性有关，两者有着类似的适应机制。
The changes of Ca2+ -ATPase activities of plasmolemma, and tonoplast membrane in roots and leaf chloroplasts in rice (Oryza sativa L. ) seedlings were investigated for exploring the mechanism of cross adaptation to different stresses in the plants during the enhancement of chilling resistance induced by cold and saltpretreatment. The results indicated that the chilling resistance of rice seedlings was enhanced markedly by cold and salt pretreatment, but this enhancement was inhibited by Ca2+ -chelate ethyleneglycol-bis-(β-aminoethylether) N, N-tetraacetie acid(EGTA) and the calmodulin inhibitor chlorpromazine(CPZ), it showed the calci.um messenger system was involved in the course of chilling resistance formation. The Ca2+ -ATP ase activity ofroot plasmolemma and tonoplast membrane as well as the Fe(CN)3-6 reduction in root plasmolemma in nonpretreated seedlings were declined markedly during the chilling stress. The Ca2+ -ATPase activities of plasmolemma, tonoplast membrane and chloroplasts as well as the Fe(CN)3-6deduction of plasmolemma were enhancedby cold preheatment. The activities of Ca2+-ATPase and Fe(CN)3-6 reduction of plasmolemma, as comparedwith nonpretreated seedlings has increased by 86. 80% and 93 .93% mepectively. The effect of salt plasment on the Ca2+ -ATPase activities of plasmolemma and chloroplast as well as Fe(CN)3-6 reduction of plasmolemma were similar to the effect of cold pretreatment. Although the Ca2+ -ATPase activity of tonoplast membrane was declined by salt pretreatment, the activity was none the less markedly higher than that of the nonpretreated seedlings. It showed that there was stronger ability of maintaining calcium homeostasis in the seedlingsfollowing two pretreatment. The results displayed that the enhancement of chilling resistance in rice seedlingswith cold and salt pretreatment might be related to the effective activation of Ca2+ -ATPase in two preatmentseedlings, because the activated Ca2+ -ATPase could bring back rapidly the raised cytoplasmic Ca2+ concentration from chilling stress to the state of calcium homeostasis, leading to the maintenance of normal functioning ofthe calcium messenger system and physiological metabolism. It seems that the adapated mechanism tO chillingstress in two seedlings with cold and salt pretreatment was similar.
基金
国家自然科学基金
关键词
水稻
盐预处理
CA^2+-ATPASE
抗寒性
交叉适应
Rice seedlings, Cold and salt pretreatment, Ca2+ -ATPase, Chilling resistance, Cross adaptation
