Plant Cell Division and its Unique Features

Abstract

Abstract In plant cells, mitosis involves many of the same ancestral components found in other eukaryotic cells, and the fundamental mitotic stages are similarly conserved. However, during the 1600 million years since plants and animals last shared a common ancestor, evolution has resulted in the appearance of unique (derived) features that reflect the evolutionary trajectory of plants. Unlike animal cells, plant cells are constrained by a cellulosic wall that largely precludes cell migration during overall development of the plant. Not only is cell migration limited by the wall, but this rigid matrix affects the character of the cytokinetic apparatus, which functions in a centrifugally expanding manner, rather than in a centripetally furrowing fashion. Another unique feature of plant cytokinesis involves the early determination (in G 2 ) of the placement of the new cell plate, which has a long‐lasting impact on plants cells, tissues and organs in the developing plant. Key Concepts: The formation of the bipolar spindle involves multiple pathways. Although plant cell division has several derived features, plants make use of a highly conserved set of tools that are used by all eukaryotes during cell division. The preprophase band is a mitotic structure unique to plants (and some green algae) that functions in the formation of the prophase spindle and presages the location of the future cell plate at cytokinesis. Flowering plants lack centrioles and focused microtubule organising centres, but nonetheless, a bipolar spindle is assembled in most plant cells at prophase. Cytokinesis involves the construction of a new cell plate that is constructed in a centrifugal fashion by the phragmoplast (which arises from the remnants of the anaphase spindle).