Plant Physiol. (1998) 117: 1529
CORRECTION
Vol. 117: 311-319, 1998
Yan, F., Feurele, R., Schaffer, S., Fortmeier, H., and Schubert,
S. Adaptation of Active Proton Pumping and Plasmalemma ATPase Activity
of Corn Roots to Low Root Medium pH.
An error was introduced in the abstract during preparation for
publication. The entire corrected abstract is reprinted below.
Corn (Zea mays L.) root
adaptation to pH 3.5 in comparison with pH 6.0 (control) was
investigated in long-term nutrient solution experiments. When pH was
gradually reduced, comparable root growth was observed irrespective of
whether the pH was 3.5 or 6.0. After low-pH adaptation, H+
release of corn roots in vivo at pH 5.6 was about 3 times higher than
that of control. Plasmalemma of corn roots was isolated for investigation in vitro. At optimum assay pH, in comparison with control, the following increases of the various parameters were caused
by low-pH treatment: (a) hydrolytic ATPase activity, (b) Vmax and Km, (c)
activation energy of H+-ATPase, (d) H+-pumping
activity, (e) H+ permeability of plasmalemma, and (f) pH
gradient across the membranes of plasmalemma vesicles. In addition,
vanadate sensitivity remained unchanged. It is concluded that
plasmalemma H+-ATPase contributes significantly to the
adaptation of corn roots to low pH. A restricted net H+
release at low pH in vivo may be attributed to the steeper pH gradient
and enhanced H+ permeability of plasmalemma but not to
deactivation of H+-ATPase. Possible mechanisms responsible
for adaptation of plasmalemma H+-ATPase to low solution pH
during plant cultivation are discussed.
