Plant and Cell Physiology, 2003, Vol. 44, No. 7 743-749
© 2003 Oxford University Press
Silicon-Induced Changes in Viscoelastic Properties of Sorghum Root Cell Walls
1 Arid Land Research Center, Tottori University, 1390 Hamasaka, Tottori, 680-0001 Japan
2 Division of Information and Biological Sciences, Graduate School of Natural Sciences, Nagoya City University, Nagoya, 467-8501 Japan
3 Department of Plant Physiology, Faculty of Natural Sciences, Comenius University, Mlynská dolina B-2, SK-842 15 Bratislava, Slovak Republic
4 Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 14, SK-842 23 Bratislava, Slovak Republic
Silicon is deposited in the endodermal tissue in sorghum (Sorghum bicolor L. Moench) roots. Its deposition is thought to protect vascular tissues in the stele against invasion by parasites and drying soil via hardening of endodermal cells. We studied the silicon-induced changes in mechanical properties of cell walls to clarify the role of silicon in sorghum root. Sorghum seedlings were grown in nutrient solution with or without silicon. The mechanical properties of cell walls were measured in three separated root zones: basal, apical and subapical. Silicon treatment decreased cell-wall extensibility in the basal zone of isolated stele tissues covered by endodermal inner tangential walls. The silicon-induced hardening of cell walls was also measured with increases in elastic moduli (E) and viscosity coefficients (
). These results provided new evidence that silicon deposition might protect the stele as a mechanical barrier by hardening the cell walls of stele and endodermal tissues. In contrast to the basal zone, silicon treatment increased cell-wall extensibility in the apical and subapical zones with concomitant decrease in E and . Simultaneously, silicon promoted root elongation. When root elongation is promoted by silicon, one of the causal factors maybe the silicon-enhanced extensibility of cell walls in the growing zone.
5 Corresponding author: E-mail, hat{at}alrc.tottori-u.ac.jp; Fax, +81-857-29-6199.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  L. Fan, R. Linker, S. Gepstein, E. Tanimoto, R. Yamamoto, and P. M. Neumann Progressive Inhibition by Water Deficit of Cell Wall Extensibility and Growth along the Elongation Zone of Maize Roots Is Related to Increased Lignin Metabolism and Progressive Stelar Accumulation of Wall Phenolics Plant Physiology, February 1, 2006; 140(2): 603 - 612. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. F. Ma, R. Shen, S. Nagao, and E. Tanimoto Aluminum Targets Elongating Cells by Reducing Cell Wall Extensibility in Wheat Roots Plant Cell Physiol., May 1, 2004; 45(5): 583 - 589. [Abstract] [Full Text] [PDF]
|
|