| 摘要: |
| 在渗透势为-0. 5和-1. 0MPa的PEG溶液胁迫下,小麦抗旱品种陕合6号根质膜(PM )Ca2+-ATPase活性分别增加59%和25%,水分敏感品种郑引1号该酶活性是先略降5%而后增加43%。8 mmol/L EGTA能明显抑制PMCa2+-ATPase活性,陕合6号抑制率为43%～77%,郑引1号为46%～56%,其中两品种在PEG胁迫以后,EGTA的抑制率减小。经对Ca2+-ATPase的动力学分析表明:随着胁迫强度的增加,陕合6号Km值分别下降46%和22%,Vmax虽略有增加,但变化不大。郑引1号Km值分别下降75%和82%,Vmax约降低到对照的1 /3. |
| 关键词: 渗透胁迫，质膜Ca2+-ATPase，冬小麦 |
| DOI： |
| 分类号:Q945.12 |
| 基金项目:国家自然科学基金资助项目 |
|
| The Ca2+-ATPase Activity and Kinetics of Winter Wheat Root Plasma Membrane Under Osmotic Stress |
|
Lu Jinyin 1 Gao Junfeng 2 Cao Cuiling 2,Lu Jinyin 1 Gao Junfeng 2 Cao Cuiling 2,Lu Jinyin 1 Gao Junfeng 2 Cao Cuiling 2
|
| Abstract: |
| Under -0. 5 and -1. 0 MPa of osmotic potential PEG stress, the wheat
root plasma membrance (PM) Ca2+-ATPase activity incresed by 59% and 25% respectively in drought-resistant Shaanhe No. 6,and the activity dropped by 5% firstly, and
then incresed by 43% in drought-sensitive Zhengyin No. 1. The PM Ca2+-ATPase was inhibited obviously by 8 mmol/L EGTA. The inhibition rate was between 43～77% in
Shaanhe N0. 6 and between 46～56% in Zhengyin No. 1, while EGTA inhibition rate reduced in the two cultivars when PEG stressed. The results of PM Ca2+-ATPase with kinetic analysis showed that Shaanhe No. 6 Km decreased by 46% and 22% respectively
and Vmax increased little or change little with the stress strength increasing. Zhengyin
No. 1 Km dropped by 75% and 82% respectively and the Vmax approximately reduced 1/3
as much as the control. |
| Key words: osmotic stress, plasma membrane Ca2+-ATPase, winter wheat |
