118
H. Pfanz
(Pfanz et al. 1987; Kronberger 1988; Yin et al. 1990, 1991) can create
proton/hydroxyl imbalances in cells and organelles, plants are equipped with
pH-stat mechanisms to cope with the excess H+ or OH-(Davies 1973, 1986;
Smith and Raven 1979; Pfanz and Heber 1986; Raven 1988). Longer-lasting
deviations from the normal "physiological" pH values are rarely recorded,
and pH is kept within very narrow limits (Pfanz and Beyschlag 1992; Pfanz
and Vollrath 1992; Heber et al., this Vol.). Cellular pH values are tightly
regulated and well protected by biochemical and biophysical buffer systems
to allow a functioning metabolism, as relatively small pH changes (e.g., less
than 0.3 pH units) may lead to severe changes in metabolism.
Acknowledgments. Most of the experiments presented above were performed within the
Sonderforschungsbereich 251 of the Universitiit Wiirzburg and within the project No.
6495-1053-21632 of the Staatsministerium fUr Landesentwicklung und Umweltfragen
(StMLU) coordinated by the Projektgruppe Bayem zur Erforschung der Wirkung von
Umweltschadstoffen (PBWU) and the EUROSILV A/Eureka 447 project No. PT BEO
51/0g 1201 5. The proofreading of Martha Virginia White is gratefully acknowledged.
References
Addanki S, Cahill FD, Sotos JF (1968) Determination of intramitochondrial pH and
intramitochondrial-extramitochondrial pH gradient of isolated heart mitochondria by
the use of 5.5-dimethyl-2.4-oxazolidinedione. J BioI Chern 243: 2337-2348
Aducchi P, Federico R, Carpinelli G, Podo F (1982) The temperature dependence of
intracellular pH in higher plant cells. Planta 156: 579-582
Baker DA (1978) Proton co-transport of organic solutes by plant cells. New Phytol 81:
485-497
Boron WF, Roos A (1976) Comparison of microelectrode, DMO, and methylamine
methods for measuring intracellular pH. Am J Physiol 231: 799-809
Bown A W (1985) CO2 and intracellular pH. Plant Cell Environ 8: 459-465
Buchanan BB, Schiirmann P, Wolosiuk RA (1976) Appearance of sedoheptulose-1.7diphosphatase activity on conversion of chloroplast fructose-1.6-diphosphatase from
dimer to monomer form. Biochem Biophys Res Commun 69: 970-978
Caldwell PD (1956) Intracellular pH. Int Rev Cytol 5: 229-277
Canny MJ (1988) Bundle sheath tissue of legume leaves as the site of recovery of solutes
from the transpiration stream. Physiol Plant 73: 457-464
Cleland RE (1981) Wall extensibility: hormones and wall extension. In: Tanner W,
Loewus FA (eds) Plant carbohydrates II. Encycl Plant Physiol NS, vol 13B. Springer,
Berlin Heidelberg New York, pp 255-273
Clevenger CB (1919) Hydrogen-ion concentration of plant juices: II Factors affecting the
hydrogen-ion concentration of plant juices. Soil Sci 8: 277-242
Colvin JR (1981) Ultrastructure of the plant cell wall: Biophysical viewpoint. In: Tanner
W, Loewus FA (eds) Plant carbohydrates II. Encyc Plant Physiol NS 13B. Springer,
Berlin Heidelberg New York, pp 9-23
Cowan JR, Raven JA, Hartung W, Farquhar GD (1982) A possible role for abscisic acid
in coupling stomatal conductance and photosynthetic carbon metabolism in leaves.
Aust J Plant Physiol 9: 489-498
Davies DD (1973) Control of and by pH. Symp Soc Exp BioI 27: 513-529
Davies DD (1986) The fine control of cytosolic pH. Physiol Plant 67: 702-706
H. Pfanz
(Pfanz et al. 1987; Kronberger 1988; Yin et al. 1990, 1991) can create
proton/hydroxyl imbalances in cells and organelles, plants are equipped with
pH-stat mechanisms to cope with the excess H+ or OH-(Davies 1973, 1986;
Smith and Raven 1979; Pfanz and Heber 1986; Raven 1988). Longer-lasting
deviations from the normal "physiological" pH values are rarely recorded,
and pH is kept within very narrow limits (Pfanz and Beyschlag 1992; Pfanz
and Vollrath 1992; Heber et al., this Vol.). Cellular pH values are tightly
regulated and well protected by biochemical and biophysical buffer systems
to allow a functioning metabolism, as relatively small pH changes (e.g., less
than 0.3 pH units) may lead to severe changes in metabolism.
Acknowledgments. Most of the experiments presented above were performed within the
Sonderforschungsbereich 251 of the Universitiit Wiirzburg and within the project No.
6495-1053-21632 of the Staatsministerium fUr Landesentwicklung und Umweltfragen
(StMLU) coordinated by the Projektgruppe Bayem zur Erforschung der Wirkung von
Umweltschadstoffen (PBWU) and the EUROSILV A/Eureka 447 project No. PT BEO
51/0g 1201 5. The proofreading of Martha Virginia White is gratefully acknowledged.
References
Addanki S, Cahill FD, Sotos JF (1968) Determination of intramitochondrial pH and
intramitochondrial-extramitochondrial pH gradient of isolated heart mitochondria by
the use of 5.5-dimethyl-2.4-oxazolidinedione. J BioI Chern 243: 2337-2348
Aducchi P, Federico R, Carpinelli G, Podo F (1982) The temperature dependence of
intracellular pH in higher plant cells. Planta 156: 579-582
Baker DA (1978) Proton co-transport of organic solutes by plant cells. New Phytol 81:
485-497
Boron WF, Roos A (1976) Comparison of microelectrode, DMO, and methylamine
methods for measuring intracellular pH. Am J Physiol 231: 799-809
Bown A W (1985) CO2 and intracellular pH. Plant Cell Environ 8: 459-465
Buchanan BB, Schiirmann P, Wolosiuk RA (1976) Appearance of sedoheptulose-1.7diphosphatase activity on conversion of chloroplast fructose-1.6-diphosphatase from
dimer to monomer form. Biochem Biophys Res Commun 69: 970-978
Caldwell PD (1956) Intracellular pH. Int Rev Cytol 5: 229-277
Canny MJ (1988) Bundle sheath tissue of legume leaves as the site of recovery of solutes
from the transpiration stream. Physiol Plant 73: 457-464
Cleland RE (1981) Wall extensibility: hormones and wall extension. In: Tanner W,
Loewus FA (eds) Plant carbohydrates II. Encycl Plant Physiol NS, vol 13B. Springer,
Berlin Heidelberg New York, pp 255-273
Clevenger CB (1919) Hydrogen-ion concentration of plant juices: II Factors affecting the
hydrogen-ion concentration of plant juices. Soil Sci 8: 277-242
Colvin JR (1981) Ultrastructure of the plant cell wall: Biophysical viewpoint. In: Tanner
W, Loewus FA (eds) Plant carbohydrates II. Encyc Plant Physiol NS 13B. Springer,
Berlin Heidelberg New York, pp 9-23
Cowan JR, Raven JA, Hartung W, Farquhar GD (1982) A possible role for abscisic acid
in coupling stomatal conductance and photosynthetic carbon metabolism in leaves.
Aust J Plant Physiol 9: 489-498
Davies DD (1973) Control of and by pH. Symp Soc Exp BioI 27: 513-529
Davies DD (1986) The fine control of cytosolic pH. Physiol Plant 67: 702-706