2008 Volume 2 Pages 29-37
A unique integrative analysis is proposed to monitor changes in the developmental processes of a particular cell type in the root, i.e. the rates of cell differentiation, production, and elongation. As a model case, effects of exogenous ethylene on differentiation, division and elongation of endodermal cells were analyzed in maize primary roots. The distance from the lowest position of the Casparian strip, a morphological marker for endodermal cell differentiation, to the root tip decreased in response to ethylene in a dose-dependent manner. The endodermal cell flux in a single cell file, an indicator for cell division, decreased in response to ethylene, although the estimated time required for an individual cell to complete the formation of the Casparian strip, as an indicator for the cell differentiation rate, did not. As indicators for cell elongation, the mature cell length did not change in the presence of ethylene, although the period for cell elongation increased. The Casparian strip formed after the endodermal cell had ceased elongation, irrespective of the presence of ethylene.
