Genetic Mechanisms Regulating Root Cap Cell Renewal in Arabidopsis thaliana L.

Synchronization of spatially separated processes of cells’ division and loss is crucial in renewal and maintenance of organ and tissue structure; however, genetic mechanisms of its regulation are poorly understood. In plants, root cap located at the root tip is quickly renewed protecting the stem cell niche against mechanical injury and performing some other important functions. In spite of continuous supply and differentiation of daughter cells from division of initials (stem cells), the root cap size does not increase because of regular sloughing of differentiated cells at its apex. In order to strictly maintain a permanent size of the root cap, it is important to synchronize divisions of stem cells with removal of the outer cell layer. In Arabidopsis thaliana, which is a model species in plant genetics, root cap structure is plain and well-ordered, and old cells are sloughed as a whole layer; that is why this species is a convenient object for investigation of the mechanisms responsible for root cap renewal. It this review, we will consider maintenance of root cap structure and size in A. thaliana and discuss the data concerning genetic control over this process and promising research avenues in this area.