Prasinophyte Explained

The prasinophytes are a group of unicellular green algae. Prasinophytes mainly include marine planktonic species, as well as some freshwater representatives.[1] [2] The prasinophytes are morphologically diverse, including flagellates with one to eight flagella and non-motile (coccoid) unicells. The cells of many species are covered with organic body scales; others are naked. Well studied genera include Ostreococcus, considered to be the smallest (ca. 0.95 μm) free-living eukaryote,[3] and Micromonas, both of which are found in marine waters worldwide. Prasinophytes have simple cellular structures, containing a single chloroplast and a single mitochondrion. The genomes are relatively small compared to other eukaryotes (about 12 Mbp for Ostreococcus[4] [5] and 21 Mbp for Micromonas[6]).At least one species, the Antarctic form Pyramimonas gelidicola, is capable of phagocytosis and is therefore a mixotrophic algae.[7]

Some authors treat the prasinophytes as a polyphyletic grouping of green algae from different clades. As the Tetraphytina emerged in the Prasinophytes, recently authors include it, rendering it monophyletic, and equivalent to chlorophyta.[8] [9]

Ecology

A study of photosynthetic gene-sequence diversity (rbcL) in the Gulf of Mexico indicated that Prasinophytes are particularly prevalent at the Subsurface Chlorophyll Maximum (SCM)[10] and several different ecotypes of Ostreococcus have been detected in the environment.[11] These ecotypes were thought to be distinguished in the environment by their adaptation to light intensities. O. lucimarinus was isolated from a high-light environment[12] and observed year-round in the coastal North Pacific Ocean.[13] RCC141 was considered low-light, because it was isolated from the lower euphotic zone. These strains, or ecotypes, were later shown to live in different habitats (open-ocean or mesotrophic) and their distributions do not appear to be connected to light availability.[14] O. tauri was isolated from a coastal lagoon and appears to be light-polyvalent. Genetic data indicates that distinct molecular differences exist between the different ecotypes that have been detected.[15]

Prasinophytes are subject to infection by large double-stranded DNA viruses belonging to the genus Prasinovirus in the family Phycodnaviridae,[16] [17] [18] as well as a Reovirus.[19] It has been estimated that from 2 to 10% of the Micromonas pusilla population is lysed per day by viruses.[20]

Phylogeny

Recent studies agree that the prasinophytes are not a natural group, being highly paraphyletic.[2] [21] [22] [23] Relationships among the groups making up the Chlorophyta are not fully resolved. The cladogram produced by Leliaert et al. 2011[2] and some modification according to Silar 2016, Leliaert 2016[24] and Lopes dos Santos et al. 2017[25] is shown below. The

blue shaded groups are or have traditionally been placed in the Prasinophyceae[1]). The species Mesostigma viride has been shown to be a member of the Streptophyta or basal Green algae. The others are member of the Chlorophyta.

As 2020 paper places the Palmophyllophyceae (prasinophyte clade VI) in a new phylum outside of the Chlorophyta and Streptophyta, the Prasinodermophyta.[26]

See also

Notes and References

  1. Sym, S. D. and Pienaar, R. N. 1993. The class Prasinophyceae. In Round, F. E. and Chapman, D. J. (eds) Progress in Phycological Research, Vol. 9. Biopress Ltd., Bristol, pp.281-376.
  2. Leliaert F, Verbruggen H, Zechman FW . Into the deep: new discoveries at the base of the green plant phylogeny . BioEssays . 33 . 9 . 683–92 . September 2011 . 21744372 . 10.1002/bies.201100035 . 40459076 .
  3. Courties C, Vaquer A, Troussellier M, Lautier J, Chrétiennot-Dinet MJ, Neveux J, Machado C, Claustre H . 1994 . 6 . Smallest eukaryotic organism . Nature . 370 . 255 . 10.1038/370255a0 . 6487. 1994Natur.370..255C . free .
  4. Derelle E, Ferraz C, Rombauts S, Rouzé P, Worden AZ, Robbens S, Partensky F, Degroeve S, Echeynié S, Cooke R, Saeys Y, Wuyts J, Jabbari K, Bowler C, Panaud O, Piégu B, Ball SG, Ral JP, Bouget FY, Piganeau G, De Baets B, Picard A, Delseny M, Demaille J, Van de Peer Y, Moreau H . Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features . Proceedings of the National Academy of Sciences of the United States of America . 103 . 31 . 11647–52 . August 2006 . 16868079 . 1544224 . 10.1073/pnas.0604795103 . 2006PNAS..10311647D . free .
  5. Palenik B, Grimwood J, Aerts A, Rouzé P, Salamov A, Putnam N, Dupont C, Jorgensen R, Derelle E, Rombauts S, Zhou K, Otillar R, Merchant SS, Podell S, Gaasterland T, Napoli C, Gendler K, Manuell A, Tai V, Vallon O, Piganeau G, Jancek S, Heijde M, Jabbari K, Bowler C, Lohr M, Robbens S, Werner G, Dubchak I, Pazour GJ, Ren Q, Paulsen I, Delwiche C, Schmutz J, Rokhsar D, Van de Peer Y, Moreau H, Grigoriev IV . 6 . The tiny eukaryote Ostreococcus provides genomic insights into the paradox of plankton speciation . Proceedings of the National Academy of Sciences of the United States of America . 104 . 18 . 7705–10 . May 2007 . 17460045 . 1863510 . 10.1073/pnas.0611046104 . 2007PNAS..104.7705P . free .
  6. Worden AZ, Lee JH, Mock T, Rouzé P, Simmons MP, Aerts AL, Allen AE, Cuvelier ML, Derelle E, Everett MV, Foulon E, Grimwood J, Gundlach H, Henrissat B, Napoli C, McDonald SM, Parker MS, Rombauts S, Salamov A, Von Dassow P, Badger JH, Coutinho PM, Demir E, Dubchak I, Gentemann C, Eikrem W, Gready JE, John U, Lanier W, Lindquist EA, Lucas S, Mayer KF, Moreau H, Not F, Otillar R, Panaud O, Pangilinan J, Paulsen I, Piegu B, Poliakov A, Robbens S, Schmutz J, Toulza E, Wyss T, Zelensky A, Zhou K, Armbrust EV, Bhattacharya D, Goodenough UW, Van de Peer Y, Grigoriev IV . 6 . Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes Micromonas . Science . 324 . 5924 . 268–72 . April 2009 . 19359590 . 10.1126/science.1167222 . 2009Sci...324..268W . 206516961 .
  7. https://pure.uhi.ac.uk/en/publications/mixotrophy-in-the-antarctic-phytoflagellate-pyramimonas-gelidicol Mixotrophy in the Antarctic phytoflagellate, Pyramimonas gelidicola (Chlorophyta: Prasinophyceae)
  8. Tevatia R, Oyler GA . Evolution of DDB1-binding WD40 (DWD) in the viridiplantae . PLOS ONE . 13 . 1 . e0190282 . 2018-01-02 . 29293590 . 5749748 . 10.1371/journal.pone.0190282 . 2018PLoSO..1390282T . free .
  9. Rockwell NC, Martin SS, Li FW, Mathews S, Lagarias JC . The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2 . The New Phytologist . 214 . 3 . 1145–1157 . May 2017 . 28106912 . 5388591 . 10.1111/nph.14422 .
  10. Wawrik B, Paul JH, Campbell L, Griffin D, Houchin L, Fuentes-Ortega A, Müller-Karger F . 2003 . Vertical Structure of the Phytoplankton Community Associated with a Coastal Plume in the Gulf of Mexico . Marine Ecology Progress Series . 251 . 87 - 101 . 10.3354/meps251087. 2003MEPS..251...87W . free .
  11. Guillou L, Eikrem W, Chrétiennot-Dinet MJ, Le Gall F, Massana R, Romari K, Pedrós-Alió C, Vaulot D . Diversity of picoplanktonic prasinophytes assessed by direct nuclear SSU rDNA sequencing of environmental samples and novel isolates retrieved from oceanic and coastal marine ecosystems . Protist . 155 . 2 . 193–214 . June 2004 . 15305796 . 10.1078/143446104774199592 . 15859454 .
  12. Worden AZ, Nolan JK, Palenik B . 2004 . Assessing the dynamics and ecology of marine picophytoplankton: The importance of the eukaryotic component. Limnology and Oceanography . 49 . 168 - 179 . 1 . 10.4319/lo.2004.49.1.0168. 2004LimOc..49..168W .
  13. Worden AZ. 2006 . Picoeukaryote diversity in coastal waters of the Pacific Ocean . Aquatic Microbial Ecology . 43 . 165 - 175 . 10.3354/ame043165. 2 . free .
  14. Demir-Hilton E, Sudek S, Cuvelier ML, Gentemann CL, Zehr JP, Worden AZ . Global distribution patterns of distinct clades of the photosynthetic picoeukaryote Ostreococcus . The ISME Journal . 5 . 7 . 1095–107 . July 2011 . 21289652 . 3146286 . 10.1038/ismej.2010.209 .
  15. Rodríguez F, Derelle E, Guillou L, Le Gall F, Vaulot D, Moreau H . Ecotype diversity in the marine picoeukaryote Ostreococcus (Chlorophyta, Prasinophyceae) . Environmental Microbiology . 7 . 6 . 853–9 . June 2005 . 15892704 . 10.1111/j.1462-2920.2005.00758.x .
  16. Mayer JA, Taylor FJ . 1979 . A virus which lyses the marine nanoflagellate, "Micromonas pusilla". Nature . 281 . 5729 . 299–301 . 10.1038/281299a0 . 1979Natur.281..299M . 4269889 .
  17. Cottrell. Matthew T.. Suttle. Curtis A. . vanc . 1991. Wide-spread occurrence and clonal variation in viruses which cause lysis of a cosmopolitan, eukaryotic marine phytoplankter, "Micromonas pusilla". Marine Ecology Progress Series . 78 . 1–9 . 10.3354/meps078001. 1991MEPS...78....1C. free.
  18. Bellec L, Grimsley N, Derelle E, Moreau H, Desdevises Y . Abundance, spatial distribution and genetic diversity of Ostreococcus tauri viruses in two different environments . Environmental Microbiology Reports . 2 . 2 . 313–21 . April 2010 . 23766083 . 10.1111/j.1758-2229.2010.00138.x .
  19. Attoui H, Jaafar FM, Belhouchet M, de Micco P, de Lamballerie X, Brussaard CP . Micromonas pusilla reovirus: a new member of the family Reoviridae assigned to a novel proposed genus (Mimoreovirus) . The Journal of General Virology . 87 . Pt 5 . 1375–83 . May 2006 . 16603541 . 10.1099/vir.0.81584-0 . free .
  20. Cottrell . Matthew T.. Suttle. Curtis A. . vanc . 1995-06-01. Dynamics of lytic virus infecting the photosynthetic marine picoflagellate "Micromonas pusilla" . Limnology and Oceanography . 40 . 4 . 730–739. 10.4319/lo.1995.40.4.0730. 1939-5590. 10.1.1.517.2324. 1995LimOc..40..730C.
  21. Lewis LA, McCourt RM . Green algae and the origin of land plants . American Journal of Botany . 91 . 10 . 1535–56 . October 2004 . 21652308 . 10.3732/ajb.91.10.1535 .
  22. Becker B, Marin B . Streptophyte algae and the origin of embryophytes . Annals of Botany . 103 . 7 . 999–1004 . May 2009 . 19273476 . 2707909 . 10.1093/aob/mcp044 .
  23. Marin B . Nested in the Chlorellales or independent class? Phylogeny and classification of the Pedinophyceae (Viridiplantae) revealed by molecular phylogenetic analyses of complete nuclear and plastid-encoded rRNA operons . Protist . 163 . 5 . 778–805 . September 2012 . 22192529 . 10.1016/j.protis.2011.11.004 .
  24. Leliaert F, Tronholm A, Lemieux C, Turmel M, DePriest MS, Bhattacharya D, Karol KG, Fredericq S, Zechman FW, Lopez-Bautista JM . Chloroplast phylogenomic analyses reveal the deepest-branching lineage of the Chlorophyta, Palmophyllophyceae class. nov . Scientific Reports . 6 . 1 . 25367 . May 2016 . 27157793 . 4860620 . 10.1038/srep25367 . 2016NatSR...625367L .
  25. Lopes Dos Santos A, Pollina T, Gourvil P, Corre E, Marie D, Garrido JL, Rodríguez F, Noël MH, Vaulot D, Eikrem W . Chloropicophyceae, a new class of picophytoplanktonic prasinophytes . Scientific Reports . 7 . 1 . 14019 . October 2017 . 29070840 . 5656628 . 10.1038/s41598-017-12412-5 . 2017NatSR...714019L .
  26. Linzhou Li . Sibo Wang . Hongli Wang . Sunil Kumar Sahu . Birger Marin . Haoyuan Li . Yan Xu . Hongping Liang . Zhen Li . Shifeng Chen . Tanja Reder . 22 June 2020 . The genome of Prasinoderma coloniale unveils the existence of a third phylum within green plants . Nature Ecology & Evolution . 4 . 9 . 1220–1231 . 10.1038/s41559-020-1221-7 . 7455551 . 32572216 . free . Yves Van de Peer . Michael Melkonian . Huan Liu . Xin Liu . Xun Xu . Gane Ka-Shu Wong . Huanming Yang . Hongli Du . Barbara Melkonian . Morten Petersen . Sebastian Wittek . Zehra Çebi . Jian Wang.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Prasinophyte".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.