major group of eukaryotes

The Archaeplastida (or kingdom Plantae sensu lato "in a broad sense") are a major group of eukaryotes. It include the photoautotrophic red algae (Rhodophyta), green algae, land plants and the minor group glaucophytes.[6] It also includes the Rhodelphidia, an eukaryotrophic flagellate that is sister to the Rhodophyta, and probably picozoans.[7] The Archaeplastida have chloroplasts that are surrounded by two membranes. All other groups which have chloroplasts, besides the amoeboid genus Paulinella, have chloroplasts surrounded by three or four membranes.

Temporal range: Calymmian - Present, 1600–0 Ma
Trees, grasses and algae in and around Sprague River, Oregon
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
(unranked): Archaeplastida
Adl et al., 2005[1]
  • Plantae Cavalier-Smith, 1981[4]
  • Primoplastobiota Reviers, 2002[source?]
  • Primoplantae Palmer et al. 2004[5]

The cells of the Archaeplastida do not have centrioles. They have mitochondria with flat cristae. They usually have a cell wall that contains cellulose. Food is stored as starch. However, these characteristics are also shared with other eukaryotes. The main evidence that the Archaeplastida form a monophyletic group comes from genetic studies. These studies show their plastids probably had a single origin. Not all scientists agree with these studies.[8][9] Photosynthetic organisms with plastids of different origin (such as brown algae) do not belong to the Archaeplastida.

The archaeplastidans fall into two main evolutionary lines. The red algae are colored with chlorophyll a and phycobiliproteins, like most cyanobacteria, and accumulate starch outside the chloroplasts. The green algae and land plants are colored with chlorophylls a and b, but do not have phycobiliproteins. Also, starch is built up inside the chloroplasts.[10] These two groups are called Viridiplantae (Latin for "green plants") or Chloroplastida. The glaucophytes have cyanobacterial color. They are unusual as they havea cell wall within their plastids (called cyanelles).[1]

Archaeplastida should not be confused with the older and obsolete name Archiplastideae. This term refers to cyanobacteria and other groups of bacteria.[11][12]

References change

  1. 1.0 1.1 Adl, S.M.; et al. (2005). "The New Higher Level Classification of Eukaryotes with Emphasis on the Taxonomy of Protists". Journal of Eukaryotic Microbiology. 52 (5): 399–451. doi:10.1111/j.1550-7408.2005.00053.x. PMID 16248873. S2CID 8060916.
  2. Yazaki, Euki; Yabuki, Akinori; Imaizumi, Ayaka; Kume, Keitaro; Hashimoto, Tetsuo; Inagaki, Yuji (31 August 2021). "Phylogenomics invokes the clade housing Cryptista, Archaeplastida, and Microheliella maris". doi:10.1101/2021.08.29.458128. S2CID 237393558. Retrieved 25 November 2021. {{cite journal}}: Cite journal requires |journal= (help)
  3. Schön, M.E.; Zlatogursky, V.V.; Singh, R.P.; et al. (17 November 2021). "Single cell genomics reveals plastid-lacking Picozoa are close relatives of red algae". Nature Communications. 12: 6651 (1): 6651. Bibcode:2021NatCo..12.6651S. doi:10.1038/s41467-021-26918-0. ISSN 2041-1723. PMC 8599508. PMID 34789758.
  4. Cavalier-Smith, T. (1981). "Eukaryote Kingdoms: Seven or Nine?"". BioSystems. 14 (3–4): 461–481. doi:10.1016/0303-2647(81)90050-2. PMID 7337818.
  5. 5.0 5.1 Palmer, Jeffrey D.; Soltis, Douglas E.; Chase, Mark W. (2004). "The plant tree of life: an overview and some points of view". American Journal of Botany. 91 (10): 1437–1445. doi:10.3732/ajb.91.10.1437. PMID 21652302.
  6. Ball, S.; Colleoni, C. (January 2011). "The evolution of glycogen and starch metabolism in eukaryotes gives molecular clues to understand the establishment of plastid endosymbiosis". Journal of Experimental Botany. 62 (6). Cenci, U.; Raj, J.N.; Tirtiaux, C.: 1775–1801. doi:10.1093/jxb/erq411. PMID 21220783.
  7. Picozoans Are Algae After All: Study | The Scientist Magazine®
  8. Parfrey. L. W.; Barbero, E.; Lasser, E; et al. (December 2006). "Evaluating support for the current classification of eukaryotic diversity". PLOS Genetics. 2 (12): e220. doi:10.1371/journal.pgen.0020220. PMC 1713255. PMID 17194223.
  9. Kim, E; Graham, L. E. (July 2008). Redfield, Rosemary Jeanne (ed.). "EEF2 analysis challenges the monophyly of Archaeplastida and Chromalveolata". PLOS ONE. 3 (7): e2621. Bibcode:2008PLoSO...3.2621K. doi:10.1371/journal.pone.0002621. PMC 2440802. PMID 18612431.
  10. Viola, R.; Nyvall, P.; Pedersén, M. (2001). "The unique features of starch metabolism in red algae". Proceedings of the Royal Society B: Biological Sciences. 268 (1474): 1417–1422. doi:10.1098/rspb.2001.1644. PMC 1088757. PMID 11429143.
  11. Copeland, H. F. (1956). The Classification of Lower Organisms. Palo Alto: Pacific Books, p. 29, [1].
  12. Bessey, C. E. (1907). "A Synopsis of Plant Phyla". Univ. Nebraska Studies. 7: 275–358.