Tissue Culturing and Harvesting of Protonemata from the Moss Physcomitrella patens

Moss spores germinate to form an alga-like filamentous structure called the protonemata. Protonemata are the earliest stage (the haploid phase) of a bryophyte life cycle and eventually give rise to a mature gametophyte. Protonemata of the moss Physcomitrella patens (P. patens) are important not only in their life cycle, but also for research. Protonemata are used for various things such as RNA/DNA extractions and protoplast isolation. We can obtain high yield of intact protoplasts from protonemata. Protoplasts can be used to study a variety of cellular processes, such as subcellular localization of proteins, isolation and analyses of intact organelles and DNA transformation. In addition, the completed sequence of the P. patens genome facilitates the use of genetic and molecular approaches to identify genes and the ability of the moss to undergo homologous recombination at appreciable frequency offers a powerful way to determine gene function. Therefore, culture of P. patens protonemata is critical.