Plant Physiology Preview Published on December 29, 2005; 10.1104/pp.105.073130
Received October 20, 2005
Returned for revision November 21, 2005
Accepted November 21, 2005
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
Ling Fan , Raphael Linker , Shimon Gepstein , Eiichi Tanimoto , Ryoichi Yamamoto , and Peter M. Neumann *
Plant Physiology lab., Department of Environmental, Water and Agricultural Engineering, Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
Eiichi Tanimoto, Plant Physiology lab., Department of Information and Biological Sciences, Graduate School of Natural Sciences, Nagoya City University, Nagoya 467-8501, Japan
Ryoichi Yamamoto, Biology and Chemistry Lab., Tezukayama University, Gakuen-Minami 3, Nara, 631-8585, Japan
* Corresponding author; email: agpetern{at}tx.technion.ac.il.
Water-deficit caused by addition of PEG 6000 at -0.5 MPa water potential to well-aerated nutrient solution for 48 h inhibited the elongation of maize (Zea mays L.) seedling primary roots. Segmental growth-rates in the root elongation zone were maintained 0 to 3 mm behind the tip but in comparison with well-watered control roots, progressive growth inhibition was initiated by water deficit as expanding cells crossed the region 3 to 9 mm behind the tip. The mechanical extensibility of the cell walls was also progressively inhibited. We investigated the possible involvement in root-growth inhibition by water deficit of alterations in metabolism and accumulation of wall-linked phenolic substances. Water deficit increased expression in the root elongation zone of transcripts of 2 genes involved in lignin biosynthesis, cinnamoyl-CoA reductase 1 and 2, after only 1h i.e. before decreases in wall extensibility. Further increases in transcript expression and increased lignin staining were detected after 48 h. Progressive stress-induced increases in wall-linked phenolics at 3 to 6 and 6 to 9 mm behind the root-tip were detected by comparing Fourier transform IR-spectra and UV-fluorescence images of isolated cell walls from water deficit and control roots. Increased UV fluorescence and lignin-staining co-located to vascular tissues in the stele. Longitudinal bisection of the elongation zone resulted in inward curvature, suggesting that inner, stelar tissues were also rate-limiting for root-growth. We suggest that spatially-localized changes in wall-phenolic-metabolism are involved in the progressive inhibition of wall extensibility and root growth and may facilitate root acclimation to drying environments.
This article has been cited by other articles:

|
 |

|
 |
 
D. Bustos, R. Lascano, A. L. Villasuso, E. Machado, M. E. Senn, A. Cordoba, and E. Taleisnik
Reductions in Maize Root-tip Elongation by Salt and Osmotic Stress do not Correlate with Apoplastic O2*- Levels
Ann. Bot.,
October 1, 2008;
102(4):
551 - 559.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. M. Neumann
Coping Mechanisms for Crop Plants in Drought-prone Environments
Ann. Bot.,
May 1, 2008;
101(7):
901 - 907.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. V. Voznesenskaya, H. Akhani, N. K. Koteyeva, S. D. X. Chuong, E. H. Roalson, O. Kiirats, V. R. Franceschi, and G. E. Edwards
Structural, biochemical, and physiological characterization of photosynthesis in two C4 subspecies of Tecticornia indica and the C3 species Tecticornia pergranulata (Chenopodiaceae)
J. Exp. Bot.,
May 1, 2008;
59(7):
1715 - 1734.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Zhu, S. Alvarez, E. L. Marsh, M. E. LeNoble, I.-J. Cho, M. Sivaguru, S. Chen, H. T. Nguyen, Y. Wu, D. P. Schachtman, et al.
Cell Wall Proteome in the Maize Primary Root Elongation Zone. II. Region-Specific Changes in Water Soluble and Lightly Ionically Bound Proteins under Water Deficit
Plant Physiology,
December 1, 2007;
145(4):
1533 - 1548.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q.-H. Ma
Characterization of a cinnamoyl-CoA reductase that is associated with stem development in wheat
J. Exp. Bot.,
June 1, 2007;
58(8):
2011 - 2021.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. M. Neumann
Evidence for long-distance xylem transport of signal peptide activity from tomato roots
J. Exp. Bot.,
June 1, 2007;
58(8):
2217 - 2223.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Tokunaga and M. Esaka
Induction of a Novel XIP-Type Xylanase Inhibitor by External Ascorbic Acid Treatment and Differential Expression of XIP-Family Genes in Rice
Plant Cell Physiol.,
May 1, 2007;
48(5):
700 - 714.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|