PLANT PHYSIOLOGY , Vol 114, Issue 2 501-509, Copyright © 1997 by American Society of Plant Biologists

WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY

Decreased Growth-Induced Water Potential (A Primary Cause of Growth Inhibition at Low Water Potentials)

H. Nonami, Y. Wu and J. S. Boyer
College of Agriculture, Ehime University, Tarumi, Matsuyama 790, Japan (H.N.)

Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of soybean (Glycine max L. Merr.) seedlings and the growth and potential difference were monitored in the stems. In water-limited plants, the inhibited stem growth increased when the roots were pressurized and it reverted to the previous rate when the pressure was released. The pressure around the roots was perceived as an increased turgor in the stem in small cells next to the xylem, but not in outlying cortical cells. This local effect implied that water transport was impeded by the small cells. The diffusivity for water was much less in the small cells than in the outlying cells. The small cells thus were a barrier that caused the growth-induced potential difference to be large during rapid growth, but to reverse locally during the early part of a water deficit. Such a barrier may be a frequent property of meristems. Because stem growth responded to the pressure-induced recovery of the potential difference across this barrier, we conclude that a decrease in the growth-induced potential difference was a primary cause of the inhibition.

This article has been cited by other articles:

				A.-C. Tang and J. S. Boyer Xylem tension affects growth-induced water potential and daily elongation of maize leaves J. Exp. Bot., March 1, 2008; 59(4): 753 - 764. [Abstract] [Full Text] [PDF]

				V. Volkov, C. Hachez, M. Moshelion, X. Draye, F. Chaumont, and W. Fricke Water permeability differs between growing and non-growing barley leaf tissues J. Exp. Bot., February 1, 2007; 58(3): 377 - 390. [Abstract] [Full Text] [PDF]

				L. I. Solari and T. M. DeJong The effect of root pressurization on water relations, shoot growth, and leaf gas exchange of peach (Prunus persica) trees on rootstocks with differing growth potential and hydraulic conductance J. Exp. Bot., June 1, 2006; 57(9): 1981 - 1989. [Abstract] [Full Text] [PDF]

				M. Keller Deficit Irrigation and Vine Mineral Nutrition Am. J. Enol. Vitic., September 1, 2005; 56(3): 267 - 283. [Abstract] [Full Text] [PDF]

				D. A. Eisenbarth and A. R. Weig Dynamics of aquaporins and water relations during hypocotyl elongation in Ricinus communis L. seedlings J. Exp. Bot., July 1, 2005; 56(417): 1831 - 1842. [Abstract] [Full Text] [PDF]

				A.-C. Tang and J. S. Boyer Root pressurization affects growth-induced water potentials and growth in dehydrated maize leaves J. Exp. Bot., November 1, 2003; 54(392): 2479 - 2488. [Abstract] [Full Text] [PDF]

				J. A. Kreps, Y. Wu, H.-S. Chang, T. Zhu, X. Wang, and J. F. Harper Transcriptome Changes for Arabidopsis in Response to Salt, Osmotic, and Cold Stress Plant Physiology, December 1, 2002; 130(4): 2129 - 2141. [Abstract] [Full Text] [PDF]

				W. FRICKE Biophysical Limitation of Cell Elongation in Cereal Leaves Ann. Bot., August 1, 2002; 90(2): 157 - 167. [Abstract] [Full Text] [PDF]

				I. C. Dodd, R. Munns, and J. B. Passioura Does shoot water status limit leaf expansion of nitrogen-deprived barley? J. Exp. Bot., August 1, 2002; 53(375): 1765 - 1770. [Abstract] [Full Text] [PDF]

				W. Fricke and W. S. Peters The Biophysics of Leaf Growth in Salt-Stressed Barley. A Study at the Cell Level Plant Physiology, May 1, 2002; 129(1): 374 - 388. [Abstract] [Full Text] [PDF]

				A.-C. Tang and J. S. Boyer Growth-induced water potentials and the growth of maize leaves J. Exp. Bot., March 1, 2002; 53(368): 489 - 503. [Abstract] [Full Text] [PDF]

				J. S. Boyer Growth-induced water potentials originate from wall yielding during growth J. Exp. Bot., July 1, 2001; 52(360): 1483 - 1488. [Abstract] [Full Text] [PDF]

				T. C. Hsiao and L.-K. Xu Sensitivity of growth of roots versus leaves to water stress: biophysical analysis and relation to water transport J. Exp. Bot., September 1, 2000; 51(350): 1595 - 1616. [Abstract] [Full Text] [PDF]

				Z. Lu and P. M. Neumann Water Stress Inhibits Hydraulic Conductance and Leaf Growth in Rice Seedlings but Not the Transport of Water via Mercury-Sensitive Water Channels in the Root Plant Physiology, May 1, 1999; 120(1): 143 - 152. [Abstract] [Full Text]

				T. E. Proseus, J. K.E. Ortega, and J. S. Boyer Separating Growth from Elastic Deformation during Cell Enlargement Plant Physiology, February 1, 1999; 119(2): 775 - 784. [Abstract] [Full Text]

				L. Bogoslavsky and P. M. Neumann Rapid Regulation by Acid pH of Cell Wall Adjustment and Leaf Growth in Maize Plants Responding to Reversal of Water Stress Plant Physiology, October 1, 1998; 118(2): 701 - 709. [Abstract] [Full Text]