Plant Physiology Preview
Published on February 5, 2004; 10.1104/pp.103.031294
Received August 4, 2003
Returned for revision September 8, 2003
Accepted November 7, 2003
Two Distinct Signaling Pathways Participate inAuxin-Induced Swelling of Pea Epidermal Protoplasts
Mutsumi Yamagami , Ken Haga , Richard M. Napier , and Moritoshi Iino *
Institute for Environmental Science, Rokkasho-mura, Aomori 039-3212, Japan (M.Y.); Botanical Gardens, Graduate School of Science, Osaka City University, Kisaichi, Katano-shi, Osaka 576-0004, Japan (K.H., M.I.); and Horticulture Research International, Warwick CV35 9EF, United Kingdom (R.M.N.)
* Corresponding author; email: iino{at}sci.osaka-cu.ac.jp.
Protoplast swelling was used to investigate auxin signaling in the growth-limiting stem epidermis. The protoplasts of epidermal cells were isolated from elongating internodes of pea (Pisum sativum). These protoplasts swelled in response to auxin, providing the clearest evidence that the epidermis can directly perceive auxin. The swelling response to the natural auxin IAA showed a biphasic dose response curve but that to the synthetic auxin 1-naphthalene acetic acid (NAA) showed a simple bell-shaped dose response curve. The responses to IAA and NAA were further analyzed using antibodies raised against ABP1 (auxin-binding protein 1), and their dependency on extracellular ions was investigated. Two signaling pathways were resolved for IAA, an ABP1-dependent pathway and an ABP1-independent pathway that is much more sensitive to IAA than the former. The response by the ABP1 pathway was eliminated by anti-ABP1 antibodies, had a higher sensitivity to NAA, and did not depend on extracellular Ca2+. In contrast, the response by the non-ABP1 pathway was not affected by anti-ABP1 antibodies, had no sensitivity to NAA, and depended on extracellular Ca2+. The swelling by either pathway required extracellular K+ and Cl-. The auxin-induced growth of pea internode segments showed similar response patterns, including the occurrence of two peaks in the dose response curve for IAA and the difference in Ca2+ requirements. It is suggested that two signaling pathways participate in auxin-induced internode growth and that the non-ABP1 pathway is more likely to be involved in the control of growth by constitutive concentrations of endogenous auxin.
This article has been cited by other articles:
|
|
|
|
 
X. Gao, S. Nagawa, G. Wang, and Z. Yang
Cell Polarity Signaling: Focus on Polar Auxin Transport
Mol Plant,
November 20, 2008;
(2008)
ssn069v1.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. Braun, J. Wyrzykowska, P. Muller, K. David, D. Couch, C. Perrot-Rechenmann, and A. J. Fleming
Conditional Repression of AUXIN BINDING PROTEIN1 Reveals That It Coordinates Cell Division and Cell Expansion during Postembryonic Shoot Development in Arabidopsis and Tobacco
PLANT CELL,
October 1, 2008;
20(10):
2746 - 2762.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Christian, W. B. Hannah, H. Luthen, and A. M. Jones
Identification of auxins by a chemical genomics approach
J. Exp. Bot.,
July 1, 2008;
59(10):
2757 - 2767.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Kawabe, B. Hansson, J. Hagenblad, A. Forrest, and D. Charlesworth
Centromere Locations and Associated Chromosome Rearrangements in Arabidopsis lyrata and A. thaliana
Genetics,
July 1, 2006;
173(3):
1613 - 1619.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Haga and M. Iino
Asymmetric distribution of auxin correlates with gravitropism and phototropism but not with autostraightening (autotropism) in pea epicotyls
J. Exp. Bot.,
March 1, 2006;
57(4):
837 - 847.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Campanoni and P. Nick
Auxin-Dependent Cell Division and Cell Elongation. 1-Naphthaleneacetic Acid and 2,4-Dichlorophenoxyacetic Acid Activate Different Pathways
Plant Physiology,
March 1, 2005;
137(3):
939 - 948.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
