EXTRACELLULAR AND INTRACELLULAR PH AND MEMBRANE-POTENTIAL CHANGES INDUCED BY K+, CL-, H2PO4-, AND NO3- UPTAKE AND FUSICOCCIN IN ROOT HAIRS OF LIMNOBIUM-STOLONIFERUM

被引:110
作者
ULLRICH, CI [1 ]
NOVACKY, AJ [1 ]
机构
[1] UNIV MISSOURI,DEPT PLANT PATHOL,COLUMBIA,MO 65211
关键词
D O I
10.1104/pp.94.4.1561
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Short-term ion uptake into roots of Limnobium stoloniferum was followed extracellularly with ion selective macroelectrodes. Cystosolic or vacuolar pH, together with the electrical membrane potential, was recorded with microelectrodes both located in the same young root hair. At the onset of chloride, phosphate, and nitrate uptake the membrane potential transiently decreased by 50 to 100 millivolts. During Cl- and H2PO4- uptake cytosolic pH decreased by 0.2 to 0.3 pH units. Nitrate induced cytosolic alkaliniation by 0.19 pH units, indicating rapid reduction. The extracellular medium alkalinized when anion uptake exceeded K+ uptake. During fusicoccin-dependent plasmalemma hyperpolarization, extracellular and cytosolic pH remained rather constant. Upon K+ absorption, FC intensified extracellular acidification and intracellular alkalinization (from 0.31 to 0.4 pH units). In the presence of Cl- FC induced intracellular acidification. Since H+ fluxes per se do not change the pH, recorded pH changes only result from fluxes of the stronger ions. The extra- and intracellular pH changes, together with membrane depolarization, exclude mechanisms as K+/A- symport or HCO3-/A- antiport for anion uptake. Though not suitable to reveal the actual H+/A- stoichiometry, the results are consistent with an H+/A- cotransport mechanism.
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页码:1561 / 1567
页数:7
相关论文
共 30 条
[1]  
ADUCCI P, 1989, NATO ASI SERIES H, V27, P143
[3]   MECHANISMS OF FUSICOCCIN ACTION - KINETIC MODIFICATION AND INACTIVATION OF K+ CHANNELS IN GUARD-CELLS [J].
BLATT, MR ;
CLINT, GM .
PLANTA, 1989, 178 (04) :509-523
[4]   INFLUENCE OF NITRATE AND CHLORIDE UPTAKE ON EXPRESSED SAP PH, ORGANIC-ACID SYNTHESIS, AND POTASSIUM ACCUMULATION IN HIGHER-PLANTS [J].
BLEVINS, DG ;
HIATT, AJ ;
LOWE, RH .
PLANT PHYSIOLOGY, 1974, 54 (01) :82-87
[5]   METABOLIC REGULATION OF ALKALINE EFFECT OF NITRATE UTILIZATION IN PLANTS [J].
DIJKSHOORN, W .
NATURE, 1962, 194 (4824) :165-&
[6]   PHOSPHATE AND MEMBRANE ELECTROPOTENTIALS IN TRIFOLIUM-REPENS L [J].
DUNLOP, J .
JOURNAL OF EXPERIMENTAL BOTANY, 1989, 40 (216) :803-807
[7]   EVIDENCE FOR AMINO ACID-H+ CO-TRANSPORT IN OAT COLEOPTILES [J].
ETHERTON, B ;
RUBINSTEIN, B .
PLANT PHYSIOLOGY, 1978, 61 (06) :933-937
[8]   THE FABRICATION OF H+-SELECTIVE LIQUID-MEMBRANE MICROELECTRODES FOR USE IN PLANT-CELLS [J].
FELLE, H ;
BERTL, A .
JOURNAL OF EXPERIMENTAL BOTANY, 1986, 37 (182) :1416-1428
[9]  
GOOD NE, 1988, PHOTOSYNTH RES, V19, P225, DOI 10.1007/BF00046875
[10]   IONIC BALANCE IN DIFFERENT TISSUES OF TOMATO PLANT IN RELATION TO NITRATE UREA OR AMMONIUM NUTRITION [J].
KIRKBY, EA ;
MENGEL, K .
PLANT PHYSIOLOGY, 1967, 42 (01) :6-&