Department of Botany, Rutgers University, Newark, New Jersey 07102.
Plant Physiol. 1978 Feb;61(2):164-9. doi: 10.1104/pp.61.2.164.
Gametophyte cells of Phaeoceros laevis (L.) Prosk. have vacuole electric potentials (PDs) of about -175 millivolts; the steady PD is not affected by light but small transient PDs result after changing from light to darkness or darkness to light. The PD is more negative than the Nernst potentials for any of the permeating ions. Changes in the concentration of any one of the external ions between 0.1 and 10 mm have only a very small effect on the PD. Increases in external pH cause the PD to depolarize by a few millivolts. Azide, 2,4-dinitrophenol, and NH(4)Cl each cause rapid and reversible depressions of the PD; the effects of these agents are similar in magnitude in the light and in the dark. Anoxia depolarizes the PD by about 30 millivolts in the light and by about 60 millivolts in the dark. Ouabain and 3-(3,4-dichlorophenyl)-1,1-dimethylurea have no effects on the PD. It is concluded that the membrane potential is controlled by an electrogenic efflux pump, possibly for H(+). It is also concluded that the source of energy for the pump is respiration and not photosynthesis.
黄苔（Phaeoceros laevis (L.) Prosk.）配子体细胞具有约-175 毫伏的液泡电动势（PD）；稳定的 PD 不受光的影响，但在从光到暗或从暗到光的转变后会产生小的瞬态 PD。PD 比任何渗透离子的能斯特电位更负。外部离子浓度在 0.1 到 10 mM 之间的任何变化对 PD 只有很小的影响。外部 pH 值的增加会使 PD 去极化几个毫伏。叠氮化物、2,4-二硝基苯酚和氯化铵都会导致 PD 迅速而可逆地下降；这些试剂在光和暗中的作用大小相似。缺氧会使 PD 在光下约 30 毫伏，在暗下约 60 毫伏去极化。哇巴因和 3-(3,4-二氯苯基）-1,1-二甲基脲对 PD 没有影响。结论是膜电位受一个生电的外排泵控制，可能是为了 H(+)。还得出结论，泵的能量来源是呼吸而不是光合作用。
