Background info on Physco biology and culture
Physcomitrella patens is a monoecious moss, which requires simple growth conditions for the completion of its life cycle. Moss gametophytes exist in two morphologically distinct forms: the juvenile filamentous tissue called protonema and the adult leafy tissue called gametophore. However, the molecular mechanism for the transition from the juvenile (protonema) to the adult (gametophore) stage is not precisely known.
Here is a good site that show the Physco Lifecycle and various structures.
P. patens life cycle. (A) A haploid spore germinates into (B) chloronemal cells, which continue to grow and differentiate into (C) caulonemal cells. (D) Gametophores, or shoots, emerge off protonemal filaments and are ultimately anchored by rhizoids that grow by tip growth from the base of the gametophore. (E) At the apex of the gametophore, both female, archegonia (arrows), and male, antheridia (arrowheads), organs form. A motile flagellate sperm fertilizes the egg and the (F) sporophyte (marked with a bracket) develops at the apex of the gametophore. (A,E,F) Kindly provided by M. Hasebe (National Institute Basic Biology, Okazaki, Japan). (B-D) M.B. (unpublished).
gametophore (PO:0030018: A shoot system that consists of the shoot axes and non-vascular leaves of a plant in the gametophytic phase.
-The gametophore has non-vascular leaflets.
protonema
protonema (PO:0030003):
A portion of chlorenchyma tissue that develops directly from a spore and grows by division of an apical cell to form filaments that are one cell wide and dicotomously branching.
Useful references:
- Rensing, et al. (2008). The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants. Science, 319, 64-69. (link)
- Prigge, M. J. and Bezanilla, M. (2010). Evolutionary crossroads in developmental biology: Physcomitrella patens. Development, 137, 3535 -3543. (link)
- Cui, et al (2011). Proteome analysis of Physcomitrella patens exposed to progressive dehydration and rehydration. Journal of Experimental Botany. link