The Moss Physcomitrella patens: A Novel Model System for Plant Development and Genomic Studies

Abstract

INTRODUCTIONThe moss Physcomitrella patens has been used as an experimental organism for more than 80 years. Within the last 15 years, its use as a model to explore plant functions has increased enormously. The ability to use gene targeting and RNA interference methods to study gene function, the availability of many tools for comparative and functional genomics (including a sequenced and assembled genome, physical and genetic maps, and more than 250,000 expressed sequence tags [ESTs]), and a dominant haploid phase that allows direct forward genetic analysis have all led to a surge of new activity. P. patens can be easily cultured and spends the majority of its life cycle in the haploid state, allowing the application of experimental techniques similar to those used in microbes and yeast. Its development is relatively simple, and it generates only a few tissues that contain a limited number of cell types. Although mosses lack vascular tissue, true roots/stems/leaves, and flowers and seeds, many signaling pathways found in angiosperms are intact in moss. For example, the phytohormones auxin, cytokinin, and abscisic acid, as well as the photomorphogenic pigments phytochrome and cryptochrome, are all interwoven into distinct but overlapping pathways and linked to clear developmental phenotypes. In addition, about one-quarter of the moss genome contains genes with no known function based on sequence motifs, raising the likelihood of successful discovery efforts to identify new and novel gene functions.

The Arabidopsis YELLOW STRIPE LIKE4 and 6 Transporters Control Iron Release from the Chloroplast

“…The moss Physcomitrella patens has only two YSL isoforms , which, very peculiarly, belong to the distinct subclass formed by Arabidopsis YSL4 and YSL6 (see Supplemental Figure 7 online). As mosses lack a vascular system (Cove et al, 2009), it might explain the absence of members from the other subclasses that are characterized by their activity in long-distance transport of metals through loading/unloading of the saps. P. patens YSLa is predicted to lie in membranes of the secretory pathway by most prediction algorithms, whereas similar to Arabidopsis YSL4 and YSL6 or rice YSL5 and YSL6, no clear targeting is predicted for P. patens YSLb.…”

Can mosses serve as model organisms for forest research?

“…patens is amenable to several transformation techniques to generate transient or stable transgenic plants, with polyethylene glycol mediated protoplast transformation being the most commonly used (Cove et al 2009;Strotbek et al 2013). RNAi-based procedures and inducible expression systems are established and available (reviewed in Strotbek et al 2013).…”

An ATP Binding Cassette Transporter Is Required for Cuticular Wax Deposition and Desiccation Tolerance in the Moss Physcomitrella patens

“…In addition, P. patens has been used extensively for bryophyte genetic studies due to its amenability to genetic modification via homologous recombination (Hohe et al, 2004;Cove et al, 2009). Moreover, following the publication of its genome sequence and the creation of associated functional genomics tools (Rensing et al, 2008), its utility has grown rapidly as a system in which to investigate the evolution of plant gene pathways.…”