Switching between symmetric and asymmetric cell divisions by abscisic acid in the moss, Physcomitrella patens

Abstract

Multicellular organisms distinctly use asymmetric cell division and symmetric cell division to create proper numbers or types of cells.
The moss, Physcomitrella patens shows asymmetric cell division in an apical stem cell of protonema, which produces a small apical stem cell with high ability to proliferate and a subapical cell with low ability to proliferate. We found when protonema of the P. patens was treated with abscisic acid (ABA), the apical stem cell produced daughter cells, both of which had the similar size and ability to proliferate, indicating that ABA induced symmetric cell division rather than asymmetric cell division. We will further study this ABA-induced cell division by using several factors which are responsible for asymmetric cell division or cell polarity.