花生幼苗下胚轴质膜Ca<sup>2+</sup>-ATP酶及其对低温胁迫的反应

花生幼苗下胚轴质膜Ca²⁺-ATP酶及其对低温胁迫的反应

1.
South China Institute of Botany, The Chinese Academy of Sciences Guangzhou 510650
2.
Department of Biology, Harbin Normal University Harbin 150080

摘要: 经6% ～12% Dextran T70 密度梯度离心,获得了纯度较高的7 d 龄花生幼苗下胚轴质膜制剂。质膜Ca²⁺ -ATPase在反应系统不存在Mg²⁺ 时,可正常表现水解ATP的活性,但此活性明显低于Mg²⁺ 激活的ATPase.Ca²⁺ -ATPase不受Na₃VO₄ 抑制,不被K⁺ 激活,而被Cl^- 抑制。Ca²⁺ -ATPase的最适pH不同于Mg²⁺ 激活的ATPase.低温胁迫显着提高质膜Ca²⁺ -ATPase的活性,推测Ca²⁺ -ATPase参与胞质中Ca²⁺ 浓度变化的调节。
- 花生幼苗下胚轴 /
- 质膜Ca²⁺-ATPase /
- 低温胁迫
Abstract: Plasma membrane were obtained from 7-day old peanut seedling hypocotyl by 6%～12% Dextran T70 density gradient centrifugation,with high quality and purity.Plasmalemma ATPase acts normally as hydrolyzing ATP without Mg²⁺ in reaction system, but the activity was lower than Mg²⁺-activated ATPase.Ca²⁺-ATPase wasn't inhibited by Na₃VO₄ and wasn't activitied by K⁺,whereas it is inhibited by Cl^-.The optimum pH of Ca²⁺-ATPase is different from that of Mg²⁺-activated ATPase.Plasma membrane Ca²⁺-ATPase activity increased notably under low temperature stress.It is suggest that the possible role of Ca²⁺-ATPase is adjusting Ca²⁺ concentration on cytoplasms.
- Hypocotyl of peanut seedling /
- Plasmalemma ATPase /
- Low temperature stress