Chapter 4.4.1 - Callose in Cell Division

Abstract

This chapter discusses the callose in cell division. In the cell plate, callose is thought to mechanically stabilize the delicate membrane networks and “create a spreading force” that widens the tubules of the TVN to produce the fenestrated plate. Callose may serve as a scaffold or matrix onto or into which the more permanent polysaccharides and proteins of the mature wall may be deposited. The formation of hydrogels by callose would allow insertion or co-gelation with other polymers in the cell plate. The subsequent removal of callose is presumably mediated by (1,3)-β-glucan endohydrolases, such as those expressed in oat endosperm, without affecting the other polymers. Callose is also involved in the junction of the cell plate with the parental wall, where its role may be related to the general role of callose as part of the wound response cascade. We speculate that the cell may anticipate rupture of the parental membrane/wall that will be necessary for the new cell plate to complete cytokinesis and is able to mobilize the cellular machinery that produces callose for a rapid and pliable repair until the strut and matrix wall can be reconstructed.