论文部分内容阅读
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。
Populus tomentosa cuttings under cold stress were treated with cold and low temperature exercise and combined with CaCl2 (CaCl2, calcium ion chelator EGTA, calcium channel blocker LaCl3 or calmodulin antagonist CPZ) The activities of malondialdehyde (MDA) and calmodulin (CaM), superoxide dismutase (SOD), peroxidase (POD) and mitochondrial ATPase (ATPase) Of the lethal temperature (LT50) were measured. The results showed that cold stress not only increased CaM content, SOD, POD and mitochondrial Ca2 + -ATPase activity of seedlings, but also decreased MDA content and semi-lethal temperature of seedlings, and reduced SOD, POD and mitochondria induced by low temperature stress The decrease of Ca2 + -ATPase activity and CaM content and the increase of MDA promoted the rapid recovery of SOD and POD, mitochondrial Ca2 + -ATPase activity and CaM level and the decrease of MDA during stress recovery. At the same time of low temperature exercise, CaCl2 treatment can enhance the effect of low temperature exercise, but this effect can be inhibited by EGTA, LaCl3 or CPZ treatment. With or without CaCl2 treatment, the increase of CaM content in seedlings could increase the activities of SOD, POD and mitochondrial Ca2 + -ATPase, and then promote the frost resistance of seedlings significantly. It appears that the Ca2 + -CaM signaling system may be involved in the regulation of SOD, POD and mitochondrial Ca2 + -ATPase activity and the cryogenic induction of frost resistance.