Phylum Chlorophyta Leliaert et al. (2011) Phylum Chlorophyta • 1-16 flagella • Flagella without mastigonems, but sometimes with hairs • Thylakoids can form grana • Pyrenoids and stigmas are intraplastidial • Starch is the major reserve polysaccharide mastigonems vs. hairs Phylum Chlorophyta Classification according to morphology: Assumes an evolution from unicellular organisms to more complex multicellular organisms Pröschold & Leliaert (2007) Phylum Chlorophyta Classification according to the ultrastructure : It assumes that the radiation of the various subgroups (classes, orders) occurred from flagellated cells Microtubular roots Distal connecting fibre (DF) Basal body Proximal connecting fibre (PF) Pröschold & Leliaert (2007) Phylum Chlorophyta Classification according to the type of covering structures Cell wall Scales (“Prasinophytes”) Theca – fused scales : (Chlorodendrophyceae) (Trebouxiophyceae) Chlorella Tetraselmis Chlorella Teca Membrana taxonomic.aad.gov.au Ulvskov et al. (2013) PLOS One 8, e76511 Arora et al. (2013) Eur. J. Phycol. 48, 61 Gerken et al. (2013) Planta 237, 239 Phylum Chlorophyta Composition of cell coverings Domozych et al. (2012) Phylum Chlorophyta Composition of Chlorella’s cell wall Control Lysozyme Lysozyme + Sulphatase Control Lysozyme Lysozyme + Sulphatase Gerken et al. (2013) Phylum Chlorophyta Composition of Chlorella’s cell wall • Sensitive to enzymes that degrade N-acetylglucosamine-containing polymers (peptidoglycan and chitin) • It has an outer protective layer with lysozyme sensitive hairs that allows more efficient action of other enzymes (e.g., chitinase) • The drastic action of lysozyme + sulfatase suggests that the cell wall consists of a polymer of sulfated N-acetylglucosamine (-> cell wall of bacteria and the surface of mammalian cells) Gerken et al. (2013) Phylum Chlorophyta Classification according to the type of mitosis : Chlorodendrophyceae Chlorophyceae “Charophytes” Trebouxiophyceae Closed mitosis with Open mitosis and Closed mitosis metacentric centrioles and mitotic spindle persistent mitotic spindle not persistent Lewis & McCourt (2004) Phylum Chlorophyta Classification according to the type of cytokinesis: “Charophytes” + Chlorophyceae Ulvophyceae Trebouxiophyceae Phragmoplast Phycoplast Mitotic spindle without cell plate, but with groove Lewis & McCourt (2004) e Leliaert et al. (2011) Phylum Chlorophyta Leliaert et al. (2011) Phylum Chlorophyta Mitose aberta com fuso mitótico persistente e citocinese por sulco (Pyramimonadales): Pröschold & Leliaert (2007) Phylum Chlorophyta Leliaert et al. (2011) Phylum Chlorophyta Closed mitosis without persistent mitotic spindle and cytokinesis with a growing furrow and phycoplast(Chlorophyceae): Pröschold & Leliaert (2007) Phylum Rhodophyta http://tolweb.org/Eukaryotes/3 Phylum Rhodophyta Rhodella reticulata Life cycle of a filamentous rhodophyte Rhodophyta vs. Cryptophyta Rhodophyta Cryptophyta Photosynthetic pigments: chlorophyll a Photosynthetic pigments: chlorophyll a, c2 phycoerythrin, phycocyanin, allophycocyanin evolutionarily related to phycoerythrins (the (all subunits encoded in the plastid genome) α -subunit is encoded in the nuclear genome) Phycobilisomes attached to the exterior of Biliproteins within the thylakoid lumen; simple thylakoids thylakoids grouped in pairs Non-flagellated in deep water habitats Flagella inserted near a crypt; superficial water habitats Floridian cytoplasmic starch Periplastic starch (between the plastid envelope and the two outer membranes) Chloroplast with a double membrane and Chloroplast surrounded by 4 membranes non-stacked thylakoids ER not associated with chloroplast ER associated with chloroplast Mitochondria with tubular cristae Mitochondria with flat cristae Phylum Euglenophyta http://tolweb.org/Eukaryotes/3 Euglenophyta n Chloroplasts with 3 membranes n Uni- or biflagellates n Chlorophyll a, b n Paramylon Horizontal gene transfer (HGT) between megagroups Multinear evolution Problems caused by HGT n It may confuse monophyletic relationships (especially in eubacteria) n The oomycetes and ciliates, both belonging to the lineage Chromalveolata (Stramenopiles and Alveolata), have traces of nuclear genes of plastid origin, suggesting that the process of endosymbiotic capture of a red algae that gave rise to the chloroplast was an event single ... or not? Photosynthetic megagroups Burki et al. (2008).