Microtubule dependent regulation of vacuolar morphogenesis in the moss, Physcomitrella patens

Abstract

Eucaryotic cells develop several essential membranous components whose morphologies and localizations are regulated by cytoskeletons. In plant cells, development of the large vacuole is indispensable for plant morphogenesis. In this study, we visualized vacuolar membranes and cytoskeletons in Physcomitrella patens by stable expressions of marker genes and analyzed the vacuolar morphogenesis during cell differentiation and growth. In protonemal cells and rhizoids, tubular vacuoles were observed around the cell cortex and cell tips and they flexibly moved. These vacuolar movements were strongly restricted by microtubule inhibitors. Furthermore, the vacuolar membranes were co-localized with microtubules and the vacuole at the cell tips appeared to be pulled by microtubules. These results suggest that the vacuolar structures and distributions are regulated by microtubules in Physcomitrella patens.