作　　者： ; ; ; ; ;

机构地区： 北京林业大学生物科学与技术学院林木花卉遗传育种教育部重点实验室

出　　处： 《植物生理与分子生物学学报》 2004年第1期59-68,共10页

摘　　要： 以零下低温锻炼和结合效应剂(CaCl2、钙离子螯合剂EGTA、钙离子通道阻断剂LaCl3或钙调素拮抗剂CPZ)处理的低温锻炼下的毛白杨(Populus tomentosa)扦插苗为试材,对其体内丙二醛(MDA)及钙调素(CaM)含量,超氧化物歧化酶(SOD)、过氧化物酶(POD)及线粒体腺苷三磷酸酶(Ca2+-ATPase)活性,以及幼苗的半致死温度(LT50)分别进行测定。结果表明,低温锻炼不仅在一定程度上提高了幼苗CaM含量,SOD、POD和线粒体Ca2+-ATPase活性,降低了MDA含量和幼苗半致死温度;而且减小了低温胁迫所引起的SOD、POD、线粒体Ca2+-ATPase活性和CaM含量的下降程度以及MDA的增加幅度,促进了胁迫后恢复过程中SOD、POD、线粒体Ca2+-ATPase活性和CaM水平的迅速回升以及MDA的下降。在低温锻炼的同时,用CaCl2处理能加强低温锻炼的效果,但这种效应可被EGTA、LaCl3或CPZ处理抑制。经或未经CaCl2处理的低温锻炼后,幼苗中CaM含量的增加有助于SOD、POD和线粒体Ca2+-ATPase活性的提高,进而对幼苗抗冻性的提高有明显的促进作用。看来,Ca2+-CaM信号系统可能参与了SOD、POD和线粒体Ca2+-ATPase活性的调节和抗冻性的低温诱导。 To explore the role of calcium-calmodulinmessenger system in the transduction of low tempera-ture signal in woody plants, Populus tomentosa cut-tings after being treated with CaCl2 (10 mmol/L), Ca2+chelator EGTA (3 mmol/L), Ca2+ channel inhibitorLaCl3 (100 mmol/L) or CaM antagonist CPZ (50 mmol/L) were used for freezing acclimation at -3℃. Thechanges in the calmodulin (CaM) and malonaldehyde(MDA) contents, the activities of superoxide dismutase(SOD), peroxidase (POD) and Ca2+-dependentadenosinetriphosphatase (Ca2+-ATPase) of mitochon-drial membrane as well as freezing resistance(expressed as LT50) of cuttings were investigated toelucidate the physiological mechanisms by which treesadapt to freezing. The results showed that freezingacclimation increased the CaM content, the activitiesof SOD, POD and Ca2+-ATPase of mitochondrial mem-brane as well as freezing resistance of cuttings, anddecreased the MDA content as compared with controlcuttings. Treatment with CaCl2 at the time of freezingacclimation enhanced the effect of freezing acclima-tion on the above-mentioned indexes, but this enhance-ment was abolished by Ca2+chelator EGTA, Ca2+ chan-nel inhibitor LaCl3 or CaM antagonist CPZ, indicat-ing that the calcium-calmodulin messenger system wasinvolved in the course of freezing resistancedevelopment. The presence of CaCl2 at the same timeof freezing acclimation also reduced the degree of de-cline in CaM content, and in SOD, POD and Ca2+-ATPase activities caused by freezing stress at -14℃,and enhanced the level of increase in CaM content,and in SOD, POD and Ca2+-ATPase activity in the re-covery periods at 25℃. The change in CaM contentwas found to be closely correlated to the levels of SOD,POD and Ca2+-ATPase, and to the degree of freezingThe Role of Calcium and Calmodulin in Freezing-Induced FreezingResistance of Populus tomentosa CuttingsLIN Shan-Zhi, ZHANG Zhi-Yi*, LIN Yuan-Zhen, ZHANG Qian, GUO Huan(Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Beij

关 键 词： 毛白杨 扦插苗 低温锻炼 钙调素 抗冻性

领　　域： [生物学]