在低温诱导毛白杨抗冻性中CaM含量和G6PDHase及ATPase活性的变化

该文对毛白杨幼苗在低温锻炼中钙调蛋白 (CaM)、6 磷酸葡萄糖脱氢酶 (G6PDHase)、腺苷三磷酸酶 (ATPase)、幼苗存活率及抗冻性的动态变化过程进行了测定 .结果表明 ,为了获得较高的抗冻性 ,生长期毛白杨幼苗的低温锻炼可分 3阶段进行 ,其中第 3阶段的 - 3℃锻炼对毛白杨幼苗抗冻性发育最有效 ;低温锻炼提高了幼苗叶片和枝条中CaM含量和G6PDHase及ATPase活性 ,同时也提高了幼苗的存活率和抗冻性 ,但毛白杨幼苗叶片的CaM含量和G6PDHase及ATPase活性提高程度较枝条明显 .进一步分析发现 ,在 - 3℃低温锻炼期间 ,上述各项指标变化与幼苗抗冻性的提高存在着明显的相关性 ,CaM可能参与G6PDHase和ATPase活性的调节 .

Changes of content of CaM, and activities of G6PDHase and ATPase during low-temperature-induced freezing tolerance of Populus tomentosa seedlings

The changes of calmodulin(CaM), glucose 6 phosphate dehydrogenase(G6PDHase), adenosin tripho sphatase(ATPase), survival rates and freezing tolerance in Populus tomentosa seedlings under cold acclimation were studied. The results showed that the cold acclimation of Populus tomentosa seedlings needed to experience three stages in order to acquire the highest freezing tolerance, and the third stage of cold acclimation at -3℃ had greater effect on the development of freezing tolerance. Cold acclimation increased the content of CaM, the activities of G6PDHase and ATPase in leaves and branches, the survival rates and freezing tolerance of seedlings.But the enhancing degree of CaM, G6PDHase and ATPase in leaves was larger than that in branches. Further analysis found that the changes of the above mentioned indexes were closely related to the freezing tolerance of seedlings; CaM possibly regulated the activities of G6PDHase and ATPase.