1 / 50

Cyanophyta and Flagellates

Cyanophyta and Flagellates. Lecture 10. OVERVIEW. Eubacteria & Protists Cyanophyta “ Phytoplankton ” Chlorophyta, Phaeophyta, Rhodophyta Vascular Plants (Gymnosperms & Angiosperms) Seagrasses – Hydrocharitaceae & Potamogetonaceae Saltmarshes – Poaceae, Juncaceae, etc

marvin-albert
Télécharger la présentation

Cyanophyta and Flagellates

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cyanophyta and Flagellates Lecture 10

  2. OVERVIEW Eubacteria & Protists • Cyanophyta • “Phytoplankton” • Chlorophyta, Phaeophyta, Rhodophyta Vascular Plants (Gymnosperms & Angiosperms) • Seagrasses – Hydrocharitaceae & Potamogetonaceae • Saltmarshes – Poaceae, Juncaceae, etc • Mangroves – Rhizophoraceae, Avicenniaceae • Beach & Dune plants

  3. Fan-Shaped Phylogenetic Tree

  4. Falkowski & Raven 2007

  5. Algal pigments

  6. “Endosymbiosis” Theory • Eukaryotic cells captured and ingested prokaryotic cells and “tamed” them to become organelles (Chloroplasts, Mitochondria – have own DNA). • Chloroplasts from blue-green algal cells, • Mitochondria from bacteria • Flagellum (9+2 microtubules) from motile, saprophytic prokaryote • Rhodophyta ingested a Cyanobacteria (chloroplast with phycobiliproteins)

  7. Organelles and endosymbiosis During the 1980s, Lynn Margulis proposed the theory of endosymbiosis to explain the origin of mitochondria and chloroplasts from permanent resident prokaryotes. According to this idea, a larger prokaryote (or perhaps early eukaryote) engulfed or surrounded a smaller prokaryote some 1.5 billion to 700 million years ago. The basic events in endosymbiosis. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

  8. Falkowski & Raven 2007

  9. “Cyanophyta” • = cyanobacteria or blue-green algae • Prokaryote Eubacteria– organelles lacking • Unicellular, colonial, filamentous forms • Chl a + Phycocyanin (blue), Phycoerythrin (red), Zeaxanthin • Heterocysts & N-fixation • http://www-cyanosite.bio.purdue.edu

  10. Heterocysts – N fixation Triple layer cell wall: glycolipid and polysaccharide • Differentiated cell that provides a low O2 environ for N-fixation (nitrogenase) • Oxygen diffusion 100x lower than normal cell • No photosystem II – no p’synth • Higher respiration (uses up O2) • Under genetic control – up regulated under low N, 1 in 10 cells become heterocysts, within 24 hrs, 600-1000 genes involved. NH4 N2 http://biology.kenyon.edu/Microbial_Biorealm/bacteria/anabaena/anabaena.htm http://www2.hawaii.edu/~scallaha/SMCsite/Research.html

  11. Heterocysts – N fixation Triple layer cell wall: glycolipid and polysaccharide • Differentiated cell that provides a low O2 environ for N-fixation (nitrogenase) • Oxygen diffusion 100x lower than normal cell • No photosystem II – no p’synth • Higher respiration (uses up O2) • Under genetic control – up regulated under low N, 1 in 10 cells become heterocysts, within 24 hrs, 600-1000 genes involved. NH4 N2

  12. Cyanophyta • Stromatolites –Bermuda, Shark Bay • 3.5 Bio – 600 Mio • O2 production – red bands (FeOx) • Warm, low energy, low grazing. • http://stromatolites.info/

  13. Cyanophyta • Stromatolites –Bermuda, Shark Bay • 3.5 Bio – 600 Mio • O2 production – red bands (FeOx) • Warm, low energy, low grazing. • http://stromatolites.info/

  14. Cyanophyta • Stromatolites –Bermuda, Shark Bay • Lyngbya • Oscillatoria • Scytonema

  15. Cyanophyta • Stromatolites –Bermuda, Shark Bay • Lyngbya • Oscillatoria • Nostoc • Trichodesmium

  16. Div Cyanophyta taxonomy • Single class: Cyanophyceae. • No flagellae, no organelles • No sexual reproduction, use transformation and conjugation (bacterial recombinant process) • Mostly freshwater, some marine and terrestrial habitats (including glaciers, hot springs, etc.) • 150 genera, 2000 spp • Prefer warm, quiescent water, often higher salinities. • Important members of the picoplankton (0.2-2um) • 5 Orders: Chroococcales, Pleurocapsales, Oscillatoriales, Nostocales, Stigonematales

  17. “Thallus” organization • Unicells – Chroococales • Colonial – Pleurocapsales • Filamentous – Oscillatoriales, Nostocales • Simple parenchymatous – Stigonematales • Two taxonomic systems: • Geitler (1932) based on morphology • Stanier (1977) based on axenic clonal culture (bacteriological techniques) http://tolweb.org/Cyanobacteria/2290 http://www-cyanosite.bio.purdue.edu/images/images.html

  18. Or. Chroococales Chroococcus Microcystis

  19. Or. Pleurocapsales CyanocystisPleurocapsa Black bands on seashore rocks

  20. Or. Oscillatoriales - Stromatolites Lyngbya Trichodesmium Lyngbya Oscillatoria Microcoleus

  21. Or. Nostocales Heterocysts Nostoc Anabaena Autofluorescence image

  22. Or. Stigonematales Fisherella

  23. Microbial Mats http://www.marine.unc.edu/Paerllab/sansalmo/index.htm

  24. Cyanophyta summary • Prokayotic Eubacteria • Simplest photosynthesizers – stromatolites and atmospheric oxygen • N-fixation in heterocysts • Oscillatoriales most important marine order. • Can form blooms: toxins, anoxia • Microbial Mats important area of research

  25. “Phytoplankton” • Passive floating • Photic Zone (0-100m depth = 0.1% PAR) • Diurnal Vertical Migration (DVM) • Sampling – Plankton Net (mesh = 40-76mm mesh size, silk or nylon). • 30 yr N. Atl dataset - Continuous Plankton Records (CPR): Plankton Atlas of the North Atlantic Ocean (1958–1999). MEPS Suppl. 3, 2004.

  26. “Phytoplankton” • Size: net- (40-80+mm), nanno- (2-20mm), pico- (0.2-2mm), ultra- (<0.2mm) • Filtering, microscopy cell counts. • 47 Pigments: chls + accessory pigments • Analysis by HPLC (High Performance Liquid Chromatography) • Pigments have potential use in Remote Sensing of presence/concentration

  27. “Phytoplankton” • Unicells • Filamentous • Colonies – chains, or spheres

  28. Flagellates • Mixed bag taxonomically, includes “picoplankton (<2mm)” • “naked” – don’t preserve well, need to be studied while living • Size <1mm – 1mm • >1x109 cells / Liter in blooms! • Ubiquitous, poorly studied to date

  29. Flagellates Euglena

  30. 2 central + 9 axial microtubules Single or paired Anterior, posterior flagellum Smooth or “hairy” Basal body = anchoring structure Flagellum

  31. 2 central + 9 axial microtubules Single or paired Anterior, posterior flagellum Smooth or “hairy” Basal body = anchoring structure Flagellum

  32. Division Chromophyta Cryptophyceae Division Heterokontophyta Dinophyceae (naked Dinoflagellates) Raphidophyceae Chrysophyceae Xanthophyceae Dictyochophyceae Prymnesiophyceae Chl a + accessory pigments (carotenoids) Division Chlorophyta Class: Euglenophyceae Prasinophyceae Chlorophyceae - Chlamydomonas Chl a + b Flagellates

  33. Class Euglenophyceae • Can also be placed in Div. Euglenophyta • Chl a+b • Eyespot • Mainly FW, some marine • 6 orders, 40 genera, 800 spp • Heterotrophy important

  34. Class Euglenophyceae • Single Class – Euglenophyceae • Chl a+b • Eyespot • Mainly FW, some marine • 6 orders, 40 genera, 800 spp • Heterotrophy important

  35. Class Prasinophyceae • 4 Orders, 16 genera, 180 spp • Cells with 1-8 flagellae • Bathycoccus - picoplankton (0.5-2um), N. Atlantic • Pterosperma - large (100-800um) cyst-like stages = phycomata. Fossil cysts from 1.2 Bya.

  36. Class Prasinophyceae • 4 Orders, 16 genera, 180 spp • Cells with 1-8 flagellae • Bathycoccus - picoplankton (0.5-2nm), N. Atlantic • Pterosperma - large (100-800nm) cyst-like stages = phycomata. Fossil cysts from 1.2 Bya.

  37. Class Chlorophyceae • 4 orders, 355 genera, 2650 spp – only v few marine. • Or Volvocales – unicell & colonial, Chlamydomonas, Volvox • Or Chlorococcales – unicell -> siphononous,Chlorella (1-2um), endosymbiont in tropical foramifera, Scenedesmus (brackish, eutrophic) • Or Chaetophorales – no marine spp • Or Oedogoniales – filamentous,Oedogonium 400spp

  38. Class Chlorophyceae • 4 orders, 355 genera, 2650 spp – only v few marine. • Or Volvocales – unicell & colonial, Chlamydomonas, Volvox • Or Chlorococcales – unicell -> siphononous,Chlorella (1-2um), endosymbiont in tropical foramifera, Scenedesmus (brackish, eutrophic) • Or Chaetophorales – no marine spp • Or Oedogoniales – filamentous,Oedogonium 400spp

  39. Division Chromophyta Cryptophyceae Division Heterokontophyta Dinophyceae (naked Dinoflagellates) Raphidophyceae Chrysophyceae Xanthophyceae Dictyochophyceae Prymnesiophyceae Chl a + accessory pigments (carotenoids) Division Chlorophyta Class: Euglenophyceae Prasinophyceae Chlorophyceae - Chlamydomonas Chl a + b Flagellates

  40. Class Cryptophyceae • 12 genera, 200 spp, ½ marine • Biflagellate, ventral gullet with trichocysts, accessory pigments (phycobilins, xanthophylls, carotenes) • Dominate nannoplankton (2-20um) in North Sea spring blooms – Cryptomonas • Massive blooms of Mesodinium in upwelling zones (Peru, Baja California)

  41. Class Cryptophyceae • Class Cryptophyceae – 12 genera, 200 spp, ½ marine • Biflagellate, ventral gullet with trichocysts, accessory pigments (phycobilins, xanthophylls, carotenes) • Dominate nannoplankton (2-20um) in North Sea spring blooms – Cryptomonas • Massive blooms of Mesodinium in upwelling zones (Peru, Baja California) Cryptomonas

  42. Class Raphidophyceae • Heterokont = long tinsel flagellum anterior, short smooth flag posterior • 1. Class Raphidophyceae – 9 genera. • Unicell flagellates, 2 flagellae, cells 50-100um, curved dorsal side, flattened ventral side with flagellar groove. • FW and marine – form HABs in Japan, DE • Chattonella, Fibrocapsa

  43. Div Heterokontophyta • Heterokont = long tinsel flagellum anterior, short smooth flag posterior • Class Raphidophyceae – 9 genera. • Unicell flagellates, 2 flagellae, cells 50-100um, curved dorsal side, flattened ventral side with flagellar groove. • FW and marine – form HABs in Japan, DE • Chattonella, Fibrocapsa Chattonella Fibrocapsa

  44. Class Chrysophyceae • Unicell, amoeboid, coccoid, filamentous forms • 2. Class Chrysophyceae, 3 orders, 200 genera, 1000 spp, v. few marine. Includes Pelagoccocus (picoplankt) and Sarcinochrysis (estuarine) • 3. Class Xanthophyceae, 7 orders, 100 genera, 600 spp, few marine. Includes the mat forming Vaucheria (50 spp) – siphonous construction

  45. 10 um Class Xanthophyceae • Unicell, amoeboid, coccoid, filamentous forms • Class Chrysophyceae, 3 orders, 200 genera, 1000 spp, v. few marine. Includes Pelagoccocus (picoplankt) and Sarcinochrysis (estuarine) • Class Xanthophyceae, 7 orders, 100 genera, 600 spp, few marine. Includes the mat forming Vaucheria (50 spp) – siphonous construction Vaucheria (from GCRL) Pelagococcus

  46. Class Dictychophyceae • 4. Class Dictyochophyceae – 2 spp extant • Single flagellum with mastigonemes (hairs). Siliceous skeleton (fossilizes well), 120 Mya evolved (silicoflagellates) • More prevalent cooler waters. Used to estimate historic SST. • Dictyocha fibula and D. speculum

  47. Div Heterokontophyta • Class Dictyochophyceae – 2 spp extant • Single flagellum with mastigonemes (hairs). Siliceous skeleton (fossilizes well), 120 Mya evolved (silicoflagellates) • More prevalent cooler waters. Used to estimate historic SST. • Dictyocha fibula and D. speculum Dictyocha

  48. Summary • Flagellates part of phytoplankton – often picoplankton, poorly studied, don’t preserve well, very small, hard to ID • 2 groups – green pigments (Div Chlorophyta), brown pigments (Div Chromophyta / Heterokontophyta) • Some groups prone to blooms and HABs

More Related