skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Cell wall yield properties of growing tissue: evaluation by in vivo stress relaxation. [Pisum sativus L]

Abstract

Growing pea stem tissue, when isolated from an external supply of water, undergoes stress relaxation because of continued loosening of the cell wall. A theoretical analysis is presented to show that such stress relaxation should result in an exponential decrease in turgor pressure down to the yield threshold (Y), with a rate constant given by phi epsilon where phi is the metabolically maintained irreversible extensibility of the cell wall and epsilon is the volumetric elastic modulus of the cell. Stress relaxation was measured in pea (Pisum sativus L.) stem segments using the pressure microprobe technique. From the rate of stress relaxation, phi of segments pretreated with water was calculated to be 0.08 per megapascal per hour while that of auxin-pretreated tissue was 0.24 per megapascal per hour. These values agreed closely with estimates of phi made by a steady-state technique. The yield threshold (0.29 megapascal) was not affected by auxin. A theoretical analysis is also presented to show that the tissue hydraulic conductance may be estimated from the T/sub 1/2/ of tissue swelling. Experimentally, pea stems had a swelling T/sub 1/2/ of 2.0 minutes, corresponding to a relative hydraulic conductance of about 2.0 per megapascal per hour. This value ismore » at least 8 times larger than phi. From these data and from computer modeling, it appears that the radial gradient in water potential which sustains water uptake in growing pea segments is small (0.04 megapascal). This means that hydraulic conductance does not substantially restrict growth. The results also demonstrate that the stimulation of growth by auxin can be entirely accounted for by the change in phi.« less

Authors:
Publication Date:
Research Org.:
Pennsylvania State Univ., University Park
OSTI Identifier:
5620371
Resource Type:
Journal Article
Journal Name:
Plant Physiol.; (United States)
Additional Journal Information:
Journal Volume: 78:2
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; CELL WALL; HYDRAULIC CONDUCTIVITY; PLANT GROWTH; PHYSIOLOGY; PLANT STEMS; STRESS RELAXATION; AUXINS; BIOLOGICAL STRESS; COMPUTERIZED SIMULATION; ELASTICITY; EQUATIONS; IN VIVO; METABOLISM; PEAS; PRESSURE MEASUREMENT; SWELLING; UPTAKE; WATER; CELL CONSTITUENTS; FOOD; GROWTH; HYDROGEN COMPOUNDS; MECHANICAL PROPERTIES; OXYGEN COMPOUNDS; PLANT GROWTH REGULATORS; PLANTS; RELAXATION; SIMULATION; TENSILE PROPERTIES; VEGETABLES; 550500* - Metabolism

Citation Formats

Cosgrove, D J. Cell wall yield properties of growing tissue: evaluation by in vivo stress relaxation. [Pisum sativus L]. United States: N. p., 1985. Web.
Cosgrove, D J. Cell wall yield properties of growing tissue: evaluation by in vivo stress relaxation. [Pisum sativus L]. United States.
Cosgrove, D J. 1985. "Cell wall yield properties of growing tissue: evaluation by in vivo stress relaxation. [Pisum sativus L]". United States.
@article{osti_5620371,
title = {Cell wall yield properties of growing tissue: evaluation by in vivo stress relaxation. [Pisum sativus L]},
author = {Cosgrove, D J},
abstractNote = {Growing pea stem tissue, when isolated from an external supply of water, undergoes stress relaxation because of continued loosening of the cell wall. A theoretical analysis is presented to show that such stress relaxation should result in an exponential decrease in turgor pressure down to the yield threshold (Y), with a rate constant given by phi epsilon where phi is the metabolically maintained irreversible extensibility of the cell wall and epsilon is the volumetric elastic modulus of the cell. Stress relaxation was measured in pea (Pisum sativus L.) stem segments using the pressure microprobe technique. From the rate of stress relaxation, phi of segments pretreated with water was calculated to be 0.08 per megapascal per hour while that of auxin-pretreated tissue was 0.24 per megapascal per hour. These values agreed closely with estimates of phi made by a steady-state technique. The yield threshold (0.29 megapascal) was not affected by auxin. A theoretical analysis is also presented to show that the tissue hydraulic conductance may be estimated from the T/sub 1/2/ of tissue swelling. Experimentally, pea stems had a swelling T/sub 1/2/ of 2.0 minutes, corresponding to a relative hydraulic conductance of about 2.0 per megapascal per hour. This value is at least 8 times larger than phi. From these data and from computer modeling, it appears that the radial gradient in water potential which sustains water uptake in growing pea segments is small (0.04 megapascal). This means that hydraulic conductance does not substantially restrict growth. The results also demonstrate that the stimulation of growth by auxin can be entirely accounted for by the change in phi.},
doi = {},
url = {https://www.osti.gov/biblio/5620371}, journal = {Plant Physiol.; (United States)},
number = ,
volume = 78:2,
place = {United States},
year = {Sat Jun 01 00:00:00 EDT 1985},
month = {Sat Jun 01 00:00:00 EDT 1985}
}