title: Etioplast and etio-chloroplast formation under natural conditions: the dark side of chlorophyll biosynthesis in angiosperms.
abstract: Chloroplast development is usually regarded as proceeding from proplastids. However, direct or indirect conversion pathways have been described in the literature, the latter involving the etioplast or the etio-chloroplast stages. Etioplasts are characterized by the absence of chlorophylls (Chl-s) and the presence of a unique inner membrane network, the prolamellar body (PLB), whereas etio-chloroplasts contain Chl-s and small PLBs interconnected with chloroplast thylakoids. As etioplast development requires growth in darkness for several days, this stage is generally regarded as a nonnatural pathway of chloroplast development occurring only under laboratory conditions. In this article, we have reviewed the data in favor of the involvement of etioplasts and etio-chloroplasts as intermediary stage(s) in chloroplast formation under natural conditions, the molecular aspects of PLB formation and we propose a dynamic model for its regulation.
authors.affiliation: Department of Plant Anatomy, Institute of Biology, Eötvös University, Pázmány P. s. 1/C, 1117 Budapest, Hungary. solymosikata@hotmail.com
authors.forename: Katalin
authors.initials: K
authors.lastname: Solymosi
authors.forename: Benoît
authors.initials: B
authors.lastname: Schoefs
mesh_terms: D002734:Chlorophyll / Q000096:biosynthesis*; D002736:Chloroplasts / Q000378:metabolism* / Q000648:ultrastructure; D003624:Darkness; D019684:Magnoliopsida / Q000378:metabolism*; D038081:Organogenesis
chemical_list: D002734:Chlorophyll