다육질성 둥근바위솔 수분저장세포의 특성

Water Storage Cells in Succulent Orostachys malacophyllus

Water storage cells (WSCs) in the leaf succulent Orostachys malacophyllus have been studied to understand their adaptive nature to its coastal habitat employing the electron microscopy. Attention has been paid to the features of vacuoles and plasmodesmata in this study, since leaf tissues in O. malacaphyllus are under continous physiological drought due to its occurrence in the shore-line environment. The WSCs occupied almost all of the leaf volume and appeared empty at low magnifications. Among the WSCs, small rudimentary vascular bundles were scattered throughout the internal volume. However, in high magnification the WSCs were vacuolate in most cases and vacuolization into a well-developed huge central vacuole was very common phenomenon. Such vacuolization has been detected within the vacuoles as well as within the cytoplasms. Well-developed plasmodesmata were often found in cells appeared to be mucilagenous. Moreover, plasmodesmata being involved in the secretion of materials or structures were even encountered. Thus, vacuolization from various sizes of vacuoles in the WSCs to have a huge central vacuole seems playing an important role in adapting the plant itself to its coastal habitat.