低温胁迫下Ca2＋-CaM信使系统对三尖杉幼苗保护酶活性的影响

用一定浓度的CaCl2、LaCl3、EGTA、CPZ等4种效应剂根施三尖杉1年生幼苗，在25℃下预处理10d后，移入-3℃下进行低温胁迫处理，分别在胁迫后24、48、72、96h时测定过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化酶（SOD）等3种保护酶的活性。结果表明：根施外源CaCl2结合低温处理可增强三尖杉幼苗3种保护酶的活性，缓解低温处理过程中保护酶活性的下降；但三尖杉幼苗内源保护酶活性可被EGTA、LaCl3以及CPZ等3种效应剂抑制。说明三尖杉幼苗抗冻性的形成受Ca2＋-CaM信号传导途径的调控。

Effects of Ca2＋- CaM Messenger System on the Protective Enzyme Activity of Cephalotaxus fortunei Seedlings Under Low Temperature Stress

The 1-year-old Cephalotaxus fortunei seedlings were fertilized by a certain concentration of CaCl2, LaCl3, EGTA and CPZ solution, pretreated at for 10 d and then moved to be treated under -3 ℃ low temperature stress. The activity of protective enzymes i. e. , CAT, POD, SOD enzyme activity of the seedlings were measured after having been treated by the low temperature stress for 24 h, 48 h, 72 h and 96 h. The results showed that CaCl2 treatment combined with low temperature stress could enhance the activity of CAT, POD, SOD enzymes and alleviate the decrease of enzyme activity during the low temperature stress. It was showed that the activity of intrinsic protective enzymes of C. fortunei seedlings might be inhibited by applying LaCl3 , EGTA and CPZ. The results suggested that the formation of cold resistance of C. fortunei seedlings was regulated by Ca2 ＋ - CaM messenger system.