Chromatin of endoreduplicated pavement cells has greater range of movement than that of diploid guard cells in Arabidopsis thaliana

Abstract

In the current model of chromatin organization in the interphase cell nucleus, chromosomes are organized into territories. Although constrained diffusion of chromatin in interphase cells has been confirmed in all cell types examined, little is known about chromatin dynamics in plant interphase cells. In this work, we measured for the first time interphase chromatin dynamics in plants using the green-fluorescent-protein-mediated chromatin-tagging system. Moreover, we compared the dynamics of diploid guard cells and endoreduplicated pavement cells. The movement of tagged loci in live seedlings shows constrained behavior in both types of nuclei. However, we found that the apparent confinement area for tagged loci in pavement cells is over 6 times larger than it is in guard cells. These findings suggest that chromatin is anchored to some component of the nucleus and that this might be responsible for the different dynamics of chromatin diffusion between diploid cells and endoreduplicated cells.