|
Plant Physiol, May 2001, Vol. 126, pp. 352-362
Hydraulic Conductance and Mercury-Sensitive Water Transport for
Roots of Opuntia acanthocarpa in Relation to Soil
Drying and Rewetting1
Pierre
Martre,
Gretchen B.
North, and
Park S.
Nobel*
Department of Organismic Biology, Ecology, and Evolution,
University of California, Los Angeles, California 90095-1606 (P.M.,
P.S.N.); and Department of Biology, Occidental College, Los Angeles,
California 90041 (G.B.N.)
Drought-induced changes in root hydraulic conductance
(LP) and mercury-sensitive water transport
were examined for distal (immature) and mid-root (mature) regions of
Opuntia acanthocarpa. During 45 d of soil drying,
LP decreased by about 67% for distal and
mid-root regions. After 8 d in rewetted soil,
LP recovered to 60% of its initial value
for both regions. Axial xylem hydraulic conductivity was only a minor
limiter of LP. Under wet conditions, HgCl2 (50 µM), which is known to block
membrane water-transport channels (aquaporins), decreased
LP and the radial hydraulic conductance for
the stele (LR, S) of the distal root region
by 32% and 41%, respectively; both LP and
LR, S recovered fully after transfer to
2-mercaptoethanol (10 mM). In contrast,
HgCl2 did not inhibit LP of the
mid-root region under wet conditions, although it reduced LR, S by 41%. Under dry conditions, neither
LP nor LR, S of
the two root regions was inhibited by HgCl2. After 8 d
of rewetting, HgCl2 decreased LP
and LR, S of the distal region by 23% and
32%, respectively, but LP and
LR, S of the mid-root region were unaltered. Changes in putative aquaporin activity accounted for about 38% of the
reduction in LP in drying soil and for 61%
of its recovery for the distal region 8 d after rewetting. In the
stele, changes in aquaporin activity accounted for about 74% of the
variable LR, S during drought and after
rewetting. Thus, aquaporins are important for regulating water movement
for roots of O. acanthocarpa.
1
This work was supported by the National Science
Foundation (grant no. IBN-9975163).
*
Corresponding author; e-mail psnobel{at}biology.ucla.edu; fax
310-206-3987.
© 2001 American Society of Plant Physiologists
This article has been cited by other articles:
|
|
|
|
 
B. Choat, G. A. Gambetta, K. A. Shackel, and M. A. Matthews
Vascular Function in Grape Berries across Development and Its Relevance to Apparent Hydraulic Isolation
Plant Physiology,
November 1, 2009;
151(3):
1677 - 1687.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Bramley, N. C. Turner, D. W. Turner, and S. D. Tyerman
Roles of Morphology, Anatomy, and Aquaporins in Determining Contrasting Hydraulic Behavior of Roots
Plant Physiology,
May 1, 2009;
150(1):
348 - 364.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Parent, C. Hachez, E. Redondo, T. Simonneau, F. Chaumont, and F. Tardieu
Drought and Abscisic Acid Effects on Aquaporin Content Translate into Changes in Hydraulic Conductivity and Leaf Growth Rate: A Trans-Scale Approach
Plant Physiology,
April 1, 2009;
149(4):
2000 - 2012.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. K. Vandeleur, G. Mayo, M. C. Shelden, M. Gilliham, B. N. Kaiser, and S. D. Tyerman
The Role of Plasma Membrane Intrinsic Protein Aquaporins in Water Transport through Roots: Diurnal and Drought Stress Responses Reveal Different Strategies between Isohydric and Anisohydric Cultivars of Grapevine
Plant Physiology,
January 1, 2009;
149(1):
445 - 460.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Li, M. Tajkarimi, and B. I. Osburn
Impact of Vacuum Cooling on Escherichia coli O157:H7 Infiltration into Lettuce Tissue
Appl. Envir. Microbiol.,
May 15, 2008;
74(10):
3138 - 3142.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Levin, J. H. Lemcoff, S. Cohen, and Y. Kapulnik
Low air humidity increases leaf-specific hydraulic conductance of Arabidopsis thaliana (L.) Heynh (Brassicaceae)
J. Exp. Bot.,
October 10, 2007;
(2007)
erm220v1.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Melkonian, L.-X. Yu, and T. L. Setter
Chilling responses of maize (Zea mays L.) seedlings: root hydraulic conductance, abscisic acid, and stomatal conductance
J. Exp. Bot.,
August 1, 2004;
55(403):
1751 - 1760.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Ranathunge, L. Kotula, E. Steudle, and R. Lafitte
Water permeability and reflection coefficient of the outer part of young rice roots are differently affected by closure of water channels (aquaporins) or blockage of apoplastic pores
J. Exp. Bot.,
February 1, 2004;
55(396):
433 - 447.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Martre, R. Morillon, F. Barrieu, G. B. North, P. S. Nobel, and M. J. Chrispeels
Plasma Membrane Aquaporins Play a Significant Role during Recovery from Water Deficit
Plant Physiology,
December 1, 2002;
130(4):
2101 - 2110.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
