Endopolyploidy in plants

Abstract

Plant growth and development is precisely programmed and achieved through three processes: cell division (proliferation), growth and differentiation. These three processes may overlap during plant organ development, when some cells start to differentiate while others continue to divide e.g. leaf epidermal cells (Harashima and Schnittger 2010). Dividing cells, called meristematic cells, increase their number and supply new cells for post-embryonic plant development. Outside the meristems non-dividing cells expand and differentiate. Cell proliferation and expansion result in varied but determined cell sizes specific for the plant, organ and tissue. The next phase in plant development is cell-type specification along with the differentiation processes. The control of all processes and the determination of final cell mass and size are poorly understood but there is increasing knowledge about the molecular mechanisms underpinning the regulatory systems. Cell sizes in plants are usually closely related to their function. There are two strategies to enlarge cell size: one is based on water uptake and vacuolar growth and the other is to increase the nuclear DNA content or the level of polyploidy, this gives rise to endopolyploidy.