|
Plant Physiol, September 2001, Vol. 127, pp. 119-130
Cytoplasmic pH Dynamics in Maize Pulvinal Cells Induced by
Gravity Vector Changes1,[w]
Eva
Johannes,*
David A.
Collings,2
Jochen C.
Rink,3 and
Nina Strömgren
Allen
Department of Botany, Box 7612, North Carolina State University,
Raleigh, North Carolina 27695-7612
In maize (Zea mays) and other grasses, changes in
orientation of stems are perceived by pulvinal tissue, which responds
to the stimulus by differential growth resulting in upward bending of
the stem. The amyloplast-containing bundle sheath cells are the sites
of gravity perception, although the initial steps of gravity perception
and transmission remain unclear. In columella cells of Arabidopsis
roots, we previously found that cytoplasmic pH (pHc) is a
mediator in early gravitropic signaling (A.C. Scott, N.S. Allen
[1999] Plant Physiol 121: 1291-1298). The question arises whether
pHc has a more general role in signaling gravity vector
changes. Using confocal ratiometric imaging and the fluorescent pH
indicator carboxy seminaphtorhodafluor acetoxymethyl ester acetate, we
measured pHc in the cells composing the maize pulvinus. When stem slices were gravistimulated and imaged on a horizontally mounted confocal microscope, pHc changes were only apparent
within the bundle sheath cells, and not in the parenchyma cells. After turning, cytoplasmic acidification was observed at the sides of the
cells, whereas the cytoplasm at the base of the cells where plastids
slowly accumulated became more basic. These changes were most apparent
in cells exhibiting net amyloplast sedimentation. Parenchyma cells and
isolated bundle sheath cells did not show any gravity-induced
pHc changes although all cell types responded to external
stimuli in the predicted way: Propionic acid and auxin treatments
induced acidification, whereas raising the external pH caused
alkalinization. The results suggest that pHc has an important role in the early signaling pathways of maize stem gravitropism.
1
This work was supported by the National
Aeronautics and Space Administration (NASA Specialized Center of
Research and Training grant no. NAGW-4984).
2
Present address: School of Biological Sciences, Macleay
Building A12, Sydney University, NSW 2006, Australia.
3
Present address: Max Planck Institute for Molecular Cell
Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
[w]
The online version of this article contains Web-only
data. The supplemental material is available at www.plantphysiol.org.
*
Corresponding author, e-mail eva_johannes{at}ncsu.edu; fax
919-515-3436.
© 2001 American Society of Plant Physiologists
This article has been cited by other articles:
|
|
|
|
 
Z. Barjaktarovic, W. Schutz, J. Madlung, C. Fladerer, A. Nordheim, and R. Hampp
Changes in the effective gravitational field strength affect the state of phosphorylation of stress-related proteins in callus cultures of Arabidopsis thaliana
J. Exp. Bot.,
March 1, 2009;
60(3):
779 - 789.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Hamamoto, J. Marui, K. Matsuoka, K. Higashi, K. Igarashi, T. Nakagawa, T. Kuroda, Y. Mori, Y. Murata, Y. Nakanishi, et al.
Characterization of a Tobacco TPK-type K+ Channel as a Novel Tonoplast K+ Channel Using Yeast Tonoplasts
J. Biol. Chem.,
January 25, 2008;
283(4):
1911 - 1920.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Sun, W. Zhang, H. Hu, B. Li, Y. Wang, Y. Zhao, K. Li, M. Liu, and X. Li
Salt Modulates Gravity Signaling Pathway to Regulate Growth Direction of Primary Roots in Arabidopsis
Plant Physiology,
January 1, 2008;
146(1):
178 - 188.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Y. Perera, C.-Y. Hung, S. Brady, G. K. Muday, and W. F. Boss
A Universal Role for Inositol 1,4,5-Trisphosphate-Mediated Signaling in Plant Gravitropism
Plant Physiology,
February 1, 2006;
140(2):
746 - 760.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Palmieri and J. Z. Kiss
Disruption of the F-actin cytoskeleton limits statolith movement in Arabidopsis hypocotyls
J. Exp. Bot.,
September 1, 2005;
56(419):
2539 - 2550.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Saito, M. T. Morita, T. Kato, and M. Tasaka
Amyloplasts and Vacuolar Membrane Dynamics in the Living Graviperceptive Cell of the Arabidopsis Inflorescence Stem
PLANT CELL,
February 1, 2005;
17(2):
548 - 558.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. B. Blancaflor and P. H. Masson
Plant Gravitropism. Unraveling the Ups and Downs of a Complex Process
Plant Physiology,
December 1, 2003;
133(4):
1677 - 1690.
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Hou, D. R. Mohamalawari, and E. B. Blancaflor
Enhanced Gravitropism of Roots with a Disrupted Cap Actin Cytoskeleton
Plant Physiology,
March 1, 2003;
131(3):
1360 - 1373.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Haruta and C. P. Constabel
Rapid Alkalinization Factors in Poplar Cell Cultures. Peptide Isolation, cDNA Cloning, and Differential Expression in Leaves and Methyl Jasmonate-Treated Cells
Plant Physiology,
February 1, 2003;
131(2):
814 - 823.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. C. Long, W. Zhao, A. M. Rashotte, G. K. Muday, and S. C. Huber
Gravity-Stimulated Changes in Auxin and Invertase Gene Expression in Maize Pulvinal Cells
Plant Physiology,
February 1, 2002;
128(2):
591 - 602.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Heilmann, J. Shin, J. Huang, I. Y. Perera, and E. Davies
Transient Dissociation of Polyribosomes and Concurrent Recruitment of Calreticulin and Calmodulin Transcripts in Gravistimulated Maize Pulvini
Plant Physiology,
November 1, 2001;
127(3):
1193 - 1203.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
