Abstract
Root apical growth is altered by genetic and/or environmental influences, which is attributable to changes in cell proliferation and volume growth. For investigating spatial profiles of these two parameters, “cell flux”-based kinematic analysis offers a powerful tool. Kinematic analysis of the root growth answers the question of where and at what rates cells proliferate and increase their volumes. The first step of kinematic analysis is to determine the spatial profile of root elongation rates from time-lapse images of a steadily growing root that are captured by a videomicroscope at a certain interval. Next, cell length is measured along the root axis on a differential interference contrast microscopic image, and the collected cell length data are used together with the spatial profile of elongation rates to determine the spatial profile of cell proliferation rates. We further analyze these profiles by an original mathematical model, which assumes several relationships between cell number, cell proliferation rate, and volume growth rate, to estimate costs of various aspects of the root growth. Here we describe the methodology of kinematic analysis of the root growth and application of our mathematical model.
