Abstract
We characterized the effect of water stress on cell division rates within the meristem of the primary root of maize (Zea mays L.) seedlings. As usual in growth kinematics, cell number density is found by counting the number of cells per small unit length of the root; growth velocity is the rate of displacement of a cellular particle found at a given distance from the apex; and the cell flux, representing the rate at which cells are moving past a spatial point, is defined as the product of velocity and cell number density. The local cell division rate is estimated by summing the derivative of cell density with respect to time, and the derivative of the cell flux with respect to distance. Relatively long (2-h) intervals were required for time-lapse photography to resolve growth velocity within the meristem. Water stress caused meristematic cells to be longer and reduced the rates of cell division, per unit length of tissue and per cell, throughout most of the meristem. Peak cell division rate was 8.2 cells mm-1 h-1 (0.10 cells cell-1 h-1) at 0.8 mm from the apex for cells under water stress, compared with 13 cells mm-1 h-1 (0.14 cells cell-1 h-1) at 1.0 mm for controls.
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- Ben-Haj-Salah H., Tardieu F. Temperature Affects Expansion Rate of Maize Leaves without Change in Spatial Distribution of Cell Length (Analysis of the Coordination between Cell Division and Cell Expansion). Plant Physiol. 1995 Nov;109(3):861–870. doi: 10.1104/pp.109.3.861. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bret-Harte M. S., Silk W. K. Nonvascular, Symplasmic Diffusion of Sucrose Cannot Satisfy the Carbon Demands of Growth in the Primary Root Tip of Zea mays L. Plant Physiol. 1994 May;105(1):19–33. doi: 10.1104/pp.105.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fraser T. E., Silk W. K., Rost T. L. Effects of low water potential on cortical cell length in growing regions of maize roots. Plant Physiol. 1990 Jun;93(2):648–651. doi: 10.1104/pp.93.2.648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martinez M. C., Jørgensen J. E., Lawton M. A., Lamb C. J., Doerner P. W. Spatial pattern of cdc2 expression in relation to meristem activity and cell proliferation during plant development. Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7360–7364. doi: 10.1073/pnas.89.16.7360. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sharp R. E., Silk W. K., Hsiao T. C. Growth of the maize primary root at low water potentials : I. Spatial distribution of expansive growth. Plant Physiol. 1988 May;87(1):50–57. doi: 10.1104/pp.87.1.50. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silk W. K., Erickson R. O. Kinematics of plant growth. J Theor Biol. 1979 Feb 21;76(4):481–501. doi: 10.1016/0022-5193(79)90014-6. [DOI] [PubMed] [Google Scholar]
- Silk W. K., Walker R. C., Labavitch J. Uronide Deposition Rates in the Primary Root of Zea mays. Plant Physiol. 1984 Mar;74(3):721–726. doi: 10.1104/pp.74.3.721. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Voetberg G. S., Sharp R. E. Growth of the Maize Primary Root at Low Water Potentials : III. Role of Increased Proline Deposition in Osmotic Adjustment. Plant Physiol. 1991 Aug;96(4):1125–1130. doi: 10.1104/pp.96.4.1125. [DOI] [PMC free article] [PubMed] [Google Scholar]