采用水培法研究酸雨胁迫对水稻叶片质膜H+-ATPase活性的影响,结果表明,高强度酸雨(pH 2.5和pH 3.0组)胁迫下,pH 2.5组质膜H+-ATPase活性显著受抑,胞内pH降低,POD活性受抑,pH3.0组质膜H+-ATPase活性上升,胞内pH降低,POD活性升高,质膜透性和MDA含量均增加,Fv/Fm和叶鲜重降低;低强度酸雨(3.0〈pH≤5.5)胁迫下,质膜H+-ATPase活性应激升高,虽胞内pH降低,POD活性升高,质膜未遭明显损伤,对生长的抑制程度明显低于高强度酸雨胁迫.可见,酸雨胁迫下,质膜功能蛋白H+-ATPase能在一定范围内调节胞内pH,进而缓解大量H+引发的活性氧积累,减轻质膜损伤,从而增强作物对酸雨胁迫的抗逆性和适应性.
The effect of acid rain(AR) on plasma membrane H+-ATPase activity of rice leaves was investigated under hydroponic conditions in order to explore the relationship between change of H+-ATPase activity and adaptation of plants to AR stress.The results show that AR(pH 2.5) led to a decrease in plasma membrane H+-ATPase activity,intracellular pH and POD activity,while AR(pH 3.0) led to an increase in plasma membrane H+-ATPase activity and POD activity and a decrease in intracellular pH Both groups led to an increase in membrane permeability and MDA content,and reduced Fv/Fm and fresh weight of leaves.AR(3.0pH≤5.5) caused an increase in the plasma membrane H+-ATPase activity and POD activity,and a decrease in intracellular pH.However,no obvious change was observed for membrane permeability and MDA content,indicating that low intensity of AR did not obviously damage cell membrane.Inhibition of low intensity AR on growth was less than that caused by high intensity AR.Under AR stress,H+-ATPase in plasma membrane can regulate intracellular pH within a certain range,and alleviate the damage caused by excess H+ on plasma membrane,thereby showing that crop stress resistance and adaptability to AR were enhanced.