Growth Rate Gradients And Extracellular Ph In Roots: How To Control An Explosion, Winfried S. Peters
May 2004
Growth Rate Gradients And Extracellular Ph In Roots: How To Control An Explosion, Winfried S. Peters
Winfried S. Peters
This paper has no abstract; this is the first paragraph. As plant growth is restricted to defined zones of growing organs, the methodologically consistent analysis of spatial growth rate patterns in organ growth zones is prerequisite for studies into the regulation of cell growth in situ (Silk, 1984). The elongation zones at the tips of growing roots are classical objects of kinematic growth analysis, which aims at the quantitative description of growth rate gradients (Erickson & Sax, 1956). Root growth zones were generally believed to be characterized by growth rates that change gradually along bell-shaped growth gradients (Erickson & Sax, …
The Biophysics Of Leaf Growth In Salt-Stressed Barley. A Study At The Cell Level., Wieland Fricke, Winfried Peters
Apr 2002
The Biophysics Of Leaf Growth In Salt-Stressed Barley. A Study At The Cell Level., Wieland Fricke, Winfried Peters
Winfried S. Peters
Biophysical parameters potentially involved in growth regulation were studied at the single-cell level in the third leaf of barley (Hordeum vulgare) after exposure to various degrees of NaCl stress for 3 to 5 d. Gradients of elongation growth were measured, and turgor pressure, osmolality, and water potentials (ψ) were determined (pressure probe and picoliter osmometry) in epidermal cells of the elongation zone and the mature blade. Cells in the elongation zone adjusted to decreasing external ψ through increases in cell osmolality that were accomplished by increased solute loads and reduced water contents. Cell turgor changed only slightly. In …
Does Growth Correlate With Turgor-Induced Elastic Strain In Stems? A Re-Evaluation Of De Vries' Classical Experiments, Winfried Peters, Maggie Farm, A. Kopf
Mar 2001
Does Growth Correlate With Turgor-Induced Elastic Strain In Stems? A Re-Evaluation Of De Vries' Classical Experiments, Winfried Peters, Maggie Farm, A. Kopf
Winfried S. Peters
The correlation between growth and turgor-induced elastic expansion was studied in hypocotyls of sunflower (Helianthus annuus) seedlings under various growth conditions. Turgor-induced elastic cell wall strain was greater in hypocotyls of faster growing seedlings, i.e. in etiolated versus light-grown ones. It also was higher in rapidly growing young seedlings as compared with nongrowing mature ones. However, analysis of the spatial distribution of elastic strain and growth demonstrated that their correspondence was only apparent. Profiles of elastic strain declined steadily from the top of the hypocotyls toward the basis, whereas the profiles of relative elemental growth rate along the …
The Correlation Of Profiles Of Surface Ph And Elongation Growth In Maize Roots, Winfried Peters, Hubert Felle
Oct 1999
The Correlation Of Profiles Of Surface Ph And Elongation Growth In Maize Roots, Winfried Peters, Hubert Felle
Winfried S. Peters
High-resolution profiles of surface pH and growth along vertically growing maize (Zea mays) primary root tips were determined simultaneously by pH-sensitive microelectrodes and marking experiments. Methodological tests were carried out that proved the reliability of our kinematic growth analysis, while questioning the validity of an alternative technique employed previously. A distal acidic zone around the meristematic region and a proximal one around the elongation zone proper were detected. This pattern as such persisted irrespective of the bulk pH value. The proximal acidic region coincided with maximum relative elemental growth rates (REGR), and both characters reacted in a correlated …
