Ca2+信号系统对低温下柑橘膜脂过氧化和抗氧化酶的影响

Effects of calcium signal system on anti-oxidant enzymes and membrane lipid peroxidation of citrus under low temperature

关键词:  Ca²⁺  EGTA  TFP  柑橘愈伤组织  抗氧化酶  膜脂过氧化

Key words:  Ca²⁺  EGTA  TFP  citrus callus  anti-oxidant enzymes  membrane lipid peroxidation

摘要:

研究不同Ca²⁺处理对低温下柑橘愈伤组织膜脂过氧化和抗氧化酶的变化。结果表明,一定低浓度的Ca²⁺(5 mmol/L)能明显减少柑橘愈伤组织膜伤害率和膜脂过氧化产物MDA的积累,增加渗透调节物质可溶性蛋白质的含量,提高膜保护性酶SOD和POD的活性,从而增强柑橘的抗寒性。采用Ca²⁺螯合剂乙二醇双乙胺醚-N,N'-四乙酸(ethylene glycol-bis-β-aminoethylether-N,N'-tetraacetic acid,EGTA)或钙调素(calmodulin,CaM)拮抗剂三氟拉嗪(trifluoperazine,TFP)处理会增加膜伤害率和MDA的积累,减少可溶性蛋白质的合成,降低SOD和POD的活性。说明钙信号系统参与调节柑橘抗寒中膜脂过氧化和保护性酶等生理生化反应。

Abstract:

Effects of calcium signal system on anti-oxidant enzymes and membrane lipid peroxidaton of citrus callus under low temperature were studied. The results showed that exogenous Ca²⁺(5 mmol/L)could markedly decrease membrane injury rate and malondialdehyde(MDA)accumulation during low temperature stress. Moreover, it could raise the content of soluble protein and increase the activity of superoxide dismutase(SOD)and peroxidase(POD).Exogenous calcium could strengthen the cold-resistant of citrus,compared with Ca-deficient treatment. But such effects were inhibited by addition of Ca²⁺ chelating agent EGTA or calmodulin antagonist TFP in the culture medium. Taken together the results above,it is suggested that calcium signal system may be involved in the membrane lipid peroxidation and protective enzyme system of cold-resistant of citrus under low temperature.