Plant and Cell Physiology, 2004, Vol. 45, No. 5 530-534
© 2004 Oxford University Press
Role of Apoplastic Ascorbate and Hydrogen Peroxide in the Control of Cell Growth in Pine Hypocotyls
Departamento de Fisiología Vegetal, Facultad de Biología, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain
The growth cessation of plant axis has been related with the formation of diphenyl bridges among the pectic components of the cell wall caused by the action of apoplastic peroxidases using hydrogen peroxide as electron acceptor. The formation of diphenyl bridges is prevented by the presence of ascorbate in the apoplastic fluid which acts as a hydrogen peroxide scavenger. The current work focuses on the role of the apoplastic ascorbate and hydrogen peroxide in the cell growth. The addition of hydrogen peroxide caused an inhibition of the auxin-induced growth as well as a significant decrease in the cell wall creep induced by acid-pH solutions. The hydrogen peroxide content in apoplastic fluid increased with the hypocotyl age and along the hypocotyl axis of 10-day-old pine seedlings, as the growth capacity decreased. On the other hand, the ascorbate content in the apoplastic fluid decreased with the hypocotyl age and along the hypocotyl axis of 10-day-old seedlings. A very significant correlation between the hydrogen peroxide apoplastic level and the growth rate as well as between the ascorbate/hydrogen peroxide molar ratio and the growth rate of hypocotyls have been found suggesting that the redox state is the main factor controlling the cell wall stiffening mechanism and thus growth in pine hypocotyls.
1 Present address: Complex Carbohydrate Research Center, The University of Georgia, Athens, GA, U.S.A.
2 Corresponding author: E-mail, bvzarra{at}usc.es; Fax, +34-981-596904.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
G. B. Monshausen, T. N. Bibikova, M. A. Messerli, C. Shi, and S. Gilroy From the Cover: Oscillations in extracellular pH and reactive oxygen species modulate tip growth of Arabidopsis root hairs PNAS, December 26, 2007; 104(52): 20996 - 21001. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Knight New ideas on root hair growth appear from the flanks PNAS, December 26, 2007; 104(52): 20649 - 20650. [Full Text] [PDF] |
||||
![]() |
A. Karkonen and S. C Fry Effect of ascorbate and its oxidation products on H2O2 production in cell-suspension cultures of Picea abies and in the absence of cells J. Exp. Bot., May 1, 2006; 57(8): 1633 - 1644. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. G. WI, A. P. SINGH, K. H. LEE, and Y. S. KIM The Pattern of Distribution of Pectin, Peroxidase and Lignin in the Middle Lamella of Secondary Xylem Fibres in Alfalfa (Medicago sativa) Ann. Bot., April 1, 2005; 95(5): 863 - 868. [Abstract] [Full Text] [PDF] |
||||


