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Plastid

February 13, 2023

The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle[1] found in the cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosymbiotic cyanobacteria. Examples include chloroplasts (used for photosynthesis), chromoplasts (used for pigment synthesis and storage), and leucoplasts (non-pigmented plastids that can sometimes differentiate).

Plant cells with visible chloroplasts.

The event which led to permanent endosymbiosis in the Archaeplastida clade (of land plants, red algae, and green algae) probably occurred with a cyanobiont (a symbiotic cyanobacteria) related to the genus Gloeomargarita, around 1.5 billion years ago.[2][3] A later primary endosymbiosis event occurred in photosynthetic Paulinella amoeboids about 90–140 million years ago. This plastid belongs to the "PS-clade" (of the cyanobacteria genera Prochlorococcus and Synechococcus).[4][5] Secondary and tertiary endosymbiosis has also occurred, in a wide variety of organisms; additionally, some organisms sequester ingested plastids in a process that is known as kleptoplasty.

A. F. W. Schimper was the first to name and provide a clear definition of plastids.[6][a] They often contain pigments used in photosynthesis, and the types of pigments in a plastid determine the cell's color. They are also the site of manufacture and storage of important chemical compounds used by the cells of autotrophic eukaryotes. They possess a double-stranded DNA molecule that is circular, like that of the circular chromosome of prokaryotic cells. Even in organisms where the plastids have lost their photosynthetic properties, the plastid is kept because of its essential role in the production of molecules like the isoprenoids.[8]

In land plants

 
Plastid types
 
Leucoplasts in plant cells.

In land plants, plastids that contain chlorophyll can carry out photosynthesis and are called chloroplasts. Plastids can also store products like starch and can synthesize fatty acids and terpenes, which can be used for producing energy and as raw material for the synthesis of other molecules. For example, the components of the plant cuticle and its epicuticular wax are synthesized by the epidermal cells from palmitic acid, which is synthesized in the chloroplasts of the mesophyll tissue.[9] All plastids are derived from proplastids, which are present in the meristematic regions of the plant. Proplastids and young chloroplasts commonly divide by binary fission, but more mature chloroplasts also have this capacity.

Plant proplastids (undifferentiated plastids) may differentiate into several forms, depending upon which function they perform in the cell. They may develop into any of the following variants:[10]

Depending on their morphology and function, plastids have the ability to differentiate, or redifferentiate, between these and other forms.

Each plastid creates multiple copies of a circular 10–250 kilobase plastome.[11][12] The number of genome copies per plastid is variable, ranging from more than 1000 in rapidly dividing cells, which, in general, contain few plastids, to 100 or fewer in mature cells, where plastid divisions have given rise to a large number of plastids. The plastome contains about 100 genes encoding ribosomal and transfer ribonucleic acids (rRNAs and tRNAs) as well as proteins involved in photosynthesis and plastid gene transcription and translation. However, these proteins only represent a small fraction of the total protein set-up necessary to build and maintain the structure and function of a particular type of plastid. Plant nuclear genes encode the vast majority of plastid proteins, and the expression of plastid genes and nuclear genes is tightly co-regulated to coordinate proper development of plastids in relation to cell differentiation.

Plastid DNA exists as large protein-DNA complexes associated with the inner envelope membrane and called 'plastid nucleoids'. Each nucleoid particle may contain more than 10 copies of the plastid DNA. The proplastid contains a single nucleoid located in the centre of the plastid. The developing plastid has many nucleoids, localized at the periphery of the plastid, bound to the inner envelope membrane. During the development of proplastids to chloroplasts, and when plastids convert from one type to another, nucleoids change in morphology, size and location within the organelle. The remodelling of nucleoids is believed to occur by modifications to the composition and abundance of nucleoid proteins.

Many plastids, particularly those responsible for photosynthesis, possess numerous internal membrane layers.

In plant cells, long thin protuberances called stromules sometimes form and extend from the main plastid body into the cytosol and interconnect several plastids. Proteins, and presumably smaller molecules, can move within stromules. Most cultured cells that are relatively large compared to other plant cells have very long and abundant stromules that extend to the cell periphery.

In 2014, evidence of possible plastid genome loss was found in Rafflesia lagascae, a non-photosynthetic parasitic flowering plant, and in Polytomella, a genus of non-photosynthetic green algae. Extensive searches for plastid genes in both Rafflesia and Polytomella yielded no results, however the conclusion that their plastomes are entirely missing is still controversial.[13] Some scientists argue that plastid genome loss is unlikely since even non-photosynthetic plastids contain genes necessary to complete various biosynthetic pathways, such as heme biosynthesis.[13][14]

In spite of the loss of the plastid genome in the Rafflesiaceae, the plastids still occur as "shells" without DNA content.[15] This looks suggestively reminiscent of hydrogenosomes in various organisms.

In algae and protists

Plastid types in algae and protists include:

  • Chloroplasts: found in the green algae (plants) and other organisms who derived their ones from the green algae.
  • Muroplasts: also known as cyanoplasts or cyanelles, the plastids of glaucophyte algae are similar to plant chloroplasts, except that they have a peptidoglycan cell wall that is similar to that of prokaryote.
  • Rhodoplasts: the red plastids found in red algae, that allow them to photosynthesize to a depth of up to 268 m.[10] The chloroplasts of plants differ from the rhodoplasts in their ability to synthesize starch, which is stored in the form of granules within the plastids. In red algae, floridean starch is synthesized and stored outside the plastids in the cytosol.[16]
  • Secondary and tertiary plastids: from endosymbiosis of green algae and red algae.
  • Leucoplast: in algae, the term is used for all unpigmented plastids. Their function differs from the leucoplasts of plants.
  • Apicoplast: the non-photosynthetic plastids of Apicomplexa derived from secondary endosymbiosis.

The plastid of photosynthetic Paulinella species is often referred to as the 'cyanelle' or chromatophore, and is used in photosynthesis;[17][18] it had a much more recent endosymbiotic event about 90–140 million years ago, and is the only other known primary endosymbiosis event of cyanobacteria.[19][20]

Etioplasts, amyloplasts and chromoplasts are plant-specific and do not occur in algae.[citation needed] Plastids in algae and hornworts may also differ from plant plastids in that they contain pyrenoids.

Inheritance

Most plants inherit the plastids from only one parent. In general, angiosperms inherit plastids from the female gamete, whereas many gymnosperms inherit plastids from the male pollen. Algae also inherit plastids from only one parent. The plastid DNA of the other parent is, thus, completely lost.

In normal intraspecific crossings (resulting in normal hybrids of one species), the inheritance of plastid DNA appears to be quite strictly 100% uniparental. In interspecific hybridisations, however, the inheritance of plastids appears to be more erratic. Although plastids inherit mainly maternally in interspecific hybridisations, there are many reports of hybrids of flowering plants that contain plastids of the father. Approximately 20% of angiosperms, including alfalfa (Medicago sativa), normally show biparental inheritance of plastids.[21]

DNA damage and repair

Plastid DNA of maize seedlings is subject to increased damage as the seedlings develop.[22] The DNA is damaged in oxidative environments created by photo-oxidative reactions and photosynthetic/respiratory electron transfer. Some DNA molecules are repaired while DNA with unrepaired damage appears to be degraded to non-functional fragments.

DNA repair proteins are encoded by the cell's nuclear genome but can be translocated to plastids where they maintain genome stability/integrity by repairing the plastid's DNA.[23] As an example, in chloroplasts of the moss Physcomitrella patens, a protein employed in DNA mismatch repair (Msh1) interacts with proteins employed in recombinational repair (RecA and RecG) to maintain plastid genome stability.[24]

Origin

Plastids are thought to be endosymbiotic cyanobacteria. The primary endosymbiotic event of the Archaeplastida is hypothesized to have occurred around 1.5 billion years ago[25] and enabled eukaryotes to carry out oxygenic photosynthesis.[26] Three evolutionary lineages in the Archaeplastida have since emerged in which the plastids are named differently: chloroplasts in green algae and/or plants, rhodoplasts in red algae, and muroplasts in the glaucophytes. The plastids differ both in their pigmentation and in their ultrastructure. For example, chloroplasts in plants and green algae have lost all phycobilisomes, the light harvesting complexes found in cyanobacteria, red algae and glaucophytes, but instead contain stroma and grana thylakoids. The glaucocystophycean plastid—in contrast to chloroplasts and rhodoplasts—is still surrounded by the remains of the cyanobacterial cell wall. All these primary plastids are surrounded by two membranes.

The plastid of photosynthetic Paulinella species is often referred to as the 'cyanelle' or chromatophore, and had a much more recent endosymbiotic event about 90–140 million years ago; it is the only known primary endosymbiosis event of cyanobacteria outside of the Archaeplastida.[17][18] The plastid belongs to the "PS-clade" (of the cyanobacteria genera Prochlorococcus and Synechococcus), which is a different sister clade to the plastids belonging to the Archaeplastida.[4][5]

In contrast to primary plastids derived from primary endosymbiosis of a prokaryoctyic cyanobacteria, complex plastids originated by secondary endosymbiosis in which a eukaryotic organism engulfed another eukaryotic organism that contained a primary plastid.[27] When a eukaryote engulfs a red or a green alga and retains the algal plastid, that plastid is typically surrounded by more than two membranes. In some cases these plastids may be reduced in their metabolic and/or photosynthetic capacity. Algae with complex plastids derived by secondary endosymbiosis of a red alga include the heterokonts, haptophytes, cryptomonads, and most dinoflagellates (= rhodoplasts). Those that endosymbiosed a green alga include the euglenids and chlorarachniophytes (= chloroplasts). The Apicomplexa, a phylum of obligate parasitic protozoa including the causative agents of malaria (Plasmodium spp.), toxoplasmosis (Toxoplasma gondii), and many other human or animal diseases also harbor a complex plastid (although this organelle has been lost in some apicomplexans, such as Cryptosporidium parvum, which causes cryptosporidiosis). The 'apicoplast' is no longer capable of photosynthesis, but is an essential organelle, and a promising target for antiparasitic drug development.

Some dinoflagellates and sea slugs, in particular of the genus Elysia, take up algae as food and keep the plastid of the digested alga to profit from the photosynthesis; after a while, the plastids are also digested. This process is known as kleptoplasty, from the Greek, kleptes, thief.

Plastid development cycle

 
An illustration of the stages of inter-conversion in plastids

In 1977 J.M Whatley proposed a plastid development cycle which said that plastid development is not always unidirectional but is instead a complicated cyclic process. Proplastids are the precursor of the more differentiated forms of plastids, as shown in the diagram to the right.[28]

See also

  • Mitochondrion – Organelle in eukaryotic cells responsible for respiration
  • Cytoskeleton – Network of filamentous proteins that forms the internal framework of cells

Notes

  1. ^ Sometimes Ernst Haeckel is credited to coin the term plastid, but his "plastid" includes nucleated cells and anucleated "cytodes"[7] and thus totally different concept from the plastid in modern literature.

References

  1. ^ Sato N (2006). "Origin and Evolution of Plastids: Genomic View on the Unification and Diversity of Plastids". In Wise RR, Hoober JK (eds.). The Structure and Function of Plastids. Advances in Photosynthesis and Respiration. Vol. 23. Springer Netherlands. pp. 75–102. doi:10.1007/978-1-4020-4061-0_4. ISBN 978-1-4020-4060-3.
  2. ^ Moore KR, Magnabosco C, Momper L, Gold DA, Bosak T, Fournier GP (2019). "An Expanded Ribosomal Phylogeny of Cyanobacteria Supports a Deep Placement of Plastids". Frontiers in Microbiology. 10: 1612. doi:10.3389/fmicb.2019.01612. PMC 6640209. PMID 31354692.
  3. ^ Vries, Jan de; Gould, Sven B. (2018-01-15). "The monoplastidic bottleneck in algae and plant evolution". Journal of Cell Science. 131 (2): jcs203414. doi:10.1242/jcs.203414. ISSN 0021-9533. PMID 28893840.
  4. ^ a b Marin, Birger; Nowack, Eva CM; Glöckner, Gernot; Melkonian, Michael (2007-06-05). "The ancestor of the Paulinella chromatophore obtained a carboxysomal operon by horizontal gene transfer from a Nitrococcus-like γ-proteobacterium". BMC Evolutionary Biology. 7: 85. doi:10.1186/1471-2148-7-85. PMC 1904183. PMID 17550603.
  5. ^ a b Ochoa de Alda, Jesús A. G.; Esteban, Rocío; Diago, María Luz; Houmard, Jean (2014-01-29). "The plastid ancestor originated among one of the major cyanobacterial lineages". Nature Communications. 5 (1): 4937. Bibcode:2014NatCo...5.4937O. doi:10.1038/ncomms5937. ISSN 2041-1723. PMID 25222494.
  6. ^ Schimper, A.F.W. (1882) "Ueber die Gestalten der Stärkebildner und Farbkörper" Botanisches Centralblatt 12(5): 175–178.
  7. ^ Haeckel, E. (1866) "Morphologische Individuen erster Ordnung: Plastiden oder Plasmastücke" in his Generelle Morphologie der Organismen Bd. 1, pp. 269-289
  8. ^ Picozoans Are Algae After All: Study | The Scientist Magazine®
  9. ^ Kolattukudy, P.E. (1996) "Biosynthetic pathways of cutin and waxes, and their sensitivity to environmental stresses", pp. 83–108 in: Plant Cuticles. G. Kerstiens (ed.), BIOS Scientific publishers Ltd., Oxford
  10. ^ a b Wise, Robert R. (2006). "1. The Diversity of Plastid Form and Function". Advances in Photosynthesis and Respiration. Vol. 23. Springer. pp. 3–26. doi:10.1007/978-1-4020-4061-0_1. ISBN 978-1-4020-4060-3.
  11. ^ Wicke, S; Schneeweiss, GM; dePamphilis, CW; Müller, KF; Quandt, D (2011). "The evolution of the plastid chromosome in land plants: gene content, gene order, gene function". Plant Molecular Biology. 76 (3–5): 273–297. doi:10.1007/s11103-011-9762-4. PMC 3104136. PMID 21424877.
  12. ^ Wicke, S; Naumann, J (2018). "Molecular evolution of plastid genomes in parasitic flowering plants". Advances in Botanical Research. 85: 315–347. doi:10.1016/bs.abr.2017.11.014. ISBN 9780128134573.
  13. ^ a b "Plants Without Plastid Genomes". The Scientist. Retrieved 2015-09-26.
  14. ^ Barbrook AC, Howe CJ, Purton S (February 2006). "Why are plastid genomes retained in non-photosynthetic organisms?". Trends in Plant Science. 11 (2): 101–8. doi:10.1016/j.tplants.2005.12.004. PMID 16406301.
  15. ^ "DNA of Giant 'Corpse Flower' Parasite Surprises Biologists". April 2021.
  16. ^ Viola R, Nyvall P, Pedersén M (July 2001). "The unique features of starch metabolism in red algae". Proceedings. Biological Sciences. 268 (1474): 1417–22. doi:10.1098/rspb.2001.1644. PMC 1088757. PMID 11429143.
  17. ^ a b Lhee, Duckhyun; Ha, Ji-San; Kim, Sunju; Park, Myung Gil; Bhattacharya, Debashish; Yoon, Hwan Su (2019-02-22). "Evolutionary dynamics of the chromatophore genome in three photosynthetic Paulinella species - Scientific Reports". Scientific Reports. 9 (1): 2560. doi:10.1038/s41598-019-38621-8. PMC 6384880. PMID 30796245.
  18. ^ a b Gabr, Arwa; Grossman, Arthur R.; Bhattacharya, Debashish (2020-05-05). Palenik, B. (ed.). "Paulinella , a model for understanding plastid primary endosymbiosis". Journal of Phycology. Wiley. 56 (4): 837–843. doi:10.1111/jpy.13003. ISSN 0022-3646. PMC 7734844. PMID 32289879.
  19. ^ Sánchez-Baracaldo, Patricia; Raven, John A.; Pisani, Davide; Knoll, Andrew H. (2017-09-12). "Early photosynthetic eukaryotes inhabited low-salinity habitats". Proceedings of the National Academy of Sciences. 114 (37): E7737–E7745. Bibcode:2017PNAS..114E7737S. doi:10.1073/pnas.1620089114. ISSN 0027-8424. PMC 5603991. PMID 28808007.
  20. ^ Luis Delaye; Cecilio Valadez-Cano; Bernardo Pérez-Zamorano (15 March 2016). "How Really Ancient Is Paulinella Chromatophora?". PLOS Currents. 8. doi:10.1371/CURRENTS.TOL.E68A099364BB1A1E129A17B4E06B0C6B. ISSN 2157-3999. PMC 4866557. PMID 28515968. Wikidata Q36374426.
  21. ^ Zhang Q (March 2010). "Why does biparental plastid inheritance revive in angiosperms?". Journal of Plant Research. 123 (2): 201–6. doi:10.1007/s10265-009-0291-z. PMID 20052516. S2CID 5108244.
  22. ^ Kumar RA, Oldenburg DJ, Bendich AJ (December 2014). "Changes in DNA damage, molecular integrity, and copy number for plastid DNA and mitochondrial DNA during maize development". Journal of Experimental Botany. 65 (22): 6425–39. doi:10.1093/jxb/eru359. PMC 4246179. PMID 25261192.
  23. ^ Oldenburg DJ, Bendich AJ (2015). "DNA maintenance in plastids and mitochondria of plants". Frontiers in Plant Science. 6: 883. doi:10.3389/fpls.2015.00883. PMC 4624840. PMID 26579143.
  24. ^ Odahara M, Kishita Y, Sekine Y (August 2017). "MSH1 maintains organelle genome stability and genetically interacts with RECA and RECG in the moss Physcomitrella patens". The Plant Journal. 91 (3): 455–465. doi:10.1111/tpj.13573. PMID 28407383.
  25. ^ Ochoa de Alda JA, Esteban R, Diago ML, Houmard J (September 2014). "The plastid ancestor originated among one of the major cyanobacterial lineages". Nature Communications. 5: 4937. Bibcode:2014NatCo...5.4937O. doi:10.1038/ncomms5937. PMID 25222494.
  26. ^ Hedges SB, Blair JE, Venturi ML, Shoe JL (January 2004). "A molecular timescale of eukaryote evolution and the rise of complex multicellular life". BMC Evolutionary Biology. 4: 2. doi:10.1186/1471-2148-4-2. PMC 341452. PMID 15005799.
  27. ^ Chan CX, Bhattachary D (2010). "The Origin of Plastids". Nature Education. 3 (9): 84.
  28. ^ Whatley, Jean M. (1978). "A Suggested Cycle of Plastid Developmental Interrelationships". The New Phytologist. 80 (3): 489–502. doi:10.1111/j.1469-8137.1978.tb01581.x. ISSN 0028-646X. JSTOR 2431207.

Further reading

  • Hanson MR, Köhler RH. . Plant Physiology Online. Archived from the original on 2005-06-14.
  • Wycliffe P, Sitbon F, Wernersson J, Ezcurra I, Ellerström M, Rask L (October 2005). "Continuous expression in tobacco leaves of a Brassica napus PEND homologue blocks differentiation of plastids and development of palisade cells". The Plant Journal. 44 (1): 1–15. doi:10.1111/j.1365-313X.2005.02482.x. PMID 16167891.
  • Birky CW (2001). (PDF). Annual Review of Genetics. 35: 125–48. doi:10.1146/annurev.genet.35.102401.090231. PMID 11700280. Archived from the original (PDF) on 2010-06-22. Retrieved 2009-03-01.
  • Chan CX, Bhattacharya D (2010). "The origins of plastids". Nature Education. 3 (9): 84.
  • Bhattacharya D, ed. (1997). Origins of Algae and their Plastids. New York: Springer-Verlag/Wein. ISBN 978-3-211-83036-9.
  • Gould SB, Waller RF, McFadden GI (2008). "Plastid evolution". Annual Review of Plant Biology. 59: 491–517. doi:10.1146/annurev.arplant.59.032607.092915. PMID 18315522. S2CID 30458113.
  • Keeling PJ (March 2010). "The endosymbiotic origin, diversification and fate of plastids". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 365 (1541): 729–48. doi:10.1098/rstb.2009.0103. PMC 2817223. PMID 20124341.

External links

  • — Co-extra research project on coexistence and traceability of GM and non-GM supply chains
  • Tree of Life Eukaryotes

February 13, 2023
plastid, plastid, greek, πλαστός, plastós, formed, molded, plural, plastids, membrane, bound, organelle, found, cells, plants, algae, some, other, eukaryotic, organisms, they, considered, intracellular, endosymbiotic, cyanobacteria, examples, include, chloropl. The plastid Greek plastos plastos formed molded plural plastids is a membrane bound organelle 1 found in the cells of plants algae and some other eukaryotic organisms They are considered to be intracellular endosymbiotic cyanobacteria Examples include chloroplasts used for photosynthesis chromoplasts used for pigment synthesis and storage and leucoplasts non pigmented plastids that can sometimes differentiate PlastidScientific classificationDomain BacteriaPhylum CyanobacteriaClade PlastidPlant cells with visible chloroplasts The event which led to permanent endosymbiosis in the Archaeplastida clade of land plants red algae and green algae probably occurred with a cyanobiont a symbiotic cyanobacteria related to the genus Gloeomargarita around 1 5 billion years ago 2 3 A later primary endosymbiosis event occurred in photosynthetic Paulinella amoeboids about 90 140 million years ago This plastid belongs to the PS clade of the cyanobacteria genera Prochlorococcus and Synechococcus 4 5 Secondary and tertiary endosymbiosis has also occurred in a wide variety of organisms additionally some organisms sequester ingested plastids in a process that is known as kleptoplasty A F W Schimper was the first to name and provide a clear definition of plastids 6 a They often contain pigments used in photosynthesis and the types of pigments in a plastid determine the cell s color They are also the site of manufacture and storage of important chemical compounds used by the cells of autotrophic eukaryotes They possess a double stranded DNA molecule that is circular like that of the circular chromosome of prokaryotic cells Even in organisms where the plastids have lost their photosynthetic properties the plastid is kept because of its essential role in the production of molecules like the isoprenoids 8 Contents 1 In land plants 2 In algae and protists 3 Inheritance 4 DNA damage and repair 5 Origin 6 Plastid development cycle 7 See also 8 Notes 9 References 10 Further reading 11 External linksIn land plants Edit Plastid types Leucoplasts in plant cells In land plants plastids that contain chlorophyll can carry out photosynthesis and are called chloroplasts Plastids can also store products like starch and can synthesize fatty acids and terpenes which can be used for producing energy and as raw material for the synthesis of other molecules For example the components of the plant cuticle and its epicuticular wax are synthesized by the epidermal cells from palmitic acid which is synthesized in the chloroplasts of the mesophyll tissue 9 All plastids are derived from proplastids which are present in the meristematic regions of the plant Proplastids and young chloroplasts commonly divide by binary fission but more mature chloroplasts also have this capacity Plant proplastids undifferentiated plastids may differentiate into several forms depending upon which function they perform in the cell They may develop into any of the following variants 10 Chloroplasts typically green plastids used for photosynthesis Etioplasts are the precursors of chloroplasts Chromoplasts coloured plastids for pigment synthesis and storage Gerontoplasts control the dismantling of the photosynthetic apparatus during plant senescence Leucoplasts colourless plastids for monoterpene synthesis leucoplasts sometimes differentiate into more specialized plastids Amyloplasts for starch storage and detecting gravity for geotropism Elaioplasts for storing fat Proteinoplasts for storing and modifying protein Tannosomes for synthesizing and producing tannins and polyphenolsDepending on their morphology and function plastids have the ability to differentiate or redifferentiate between these and other forms Each plastid creates multiple copies of a circular 10 250 kilobase plastome 11 12 The number of genome copies per plastid is variable ranging from more than 1000 in rapidly dividing cells which in general contain few plastids to 100 or fewer in mature cells where plastid divisions have given rise to a large number of plastids The plastome contains about 100 genes encoding ribosomal and transfer ribonucleic acids rRNAs and tRNAs as well as proteins involved in photosynthesis and plastid gene transcription and translation However these proteins only represent a small fraction of the total protein set up necessary to build and maintain the structure and function of a particular type of plastid Plant nuclear genes encode the vast majority of plastid proteins and the expression of plastid genes and nuclear genes is tightly co regulated to coordinate proper development of plastids in relation to cell differentiation Plastid DNA exists as large protein DNA complexes associated with the inner envelope membrane and called plastid nucleoids Each nucleoid particle may contain more than 10 copies of the plastid DNA The proplastid contains a single nucleoid located in the centre of the plastid The developing plastid has many nucleoids localized at the periphery of the plastid bound to the inner envelope membrane During the development of proplastids to chloroplasts and when plastids convert from one type to another nucleoids change in morphology size and location within the organelle The remodelling of nucleoids is believed to occur by modifications to the composition and abundance of nucleoid proteins Many plastids particularly those responsible for photosynthesis possess numerous internal membrane layers In plant cells long thin protuberances called stromules sometimes form and extend from the main plastid body into the cytosol and interconnect several plastids Proteins and presumably smaller molecules can move within stromules Most cultured cells that are relatively large compared to other plant cells have very long and abundant stromules that extend to the cell periphery In 2014 evidence of possible plastid genome loss was found in Rafflesia lagascae a non photosynthetic parasitic flowering plant and in Polytomella a genus of non photosynthetic green algae Extensive searches for plastid genes in both Rafflesia and Polytomella yielded no results however the conclusion that their plastomes are entirely missing is still controversial 13 Some scientists argue that plastid genome loss is unlikely since even non photosynthetic plastids contain genes necessary to complete various biosynthetic pathways such as heme biosynthesis 13 14 In spite of the loss of the plastid genome in the Rafflesiaceae the plastids still occur as shells without DNA content 15 This looks suggestively reminiscent of hydrogenosomes in various organisms In algae and protists EditPlastid types in algae and protists include Chloroplasts found in the green algae plants and other organisms who derived their ones from the green algae Muroplasts also known as cyanoplasts or cyanelles the plastids of glaucophyte algae are similar to plant chloroplasts except that they have a peptidoglycan cell wall that is similar to that of prokaryote Rhodoplasts the red plastids found in red algae that allow them to photosynthesize to a depth of up to 268 m 10 The chloroplasts of plants differ from the rhodoplasts in their ability to synthesize starch which is stored in the form of granules within the plastids In red algae floridean starch is synthesized and stored outside the plastids in the cytosol 16 Secondary and tertiary plastids from endosymbiosis of green algae and red algae Leucoplast in algae the term is used for all unpigmented plastids Their function differs from the leucoplasts of plants Apicoplast the non photosynthetic plastids of Apicomplexa derived from secondary endosymbiosis The plastid of photosynthetic Paulinella species is often referred to as the cyanelle or chromatophore and is used in photosynthesis 17 18 it had a much more recent endosymbiotic event about 90 140 million years ago and is the only other known primary endosymbiosis event of cyanobacteria 19 20 Etioplasts amyloplasts and chromoplasts are plant specific and do not occur in algae citation needed Plastids in algae and hornworts may also differ from plant plastids in that they contain pyrenoids Inheritance EditMost plants inherit the plastids from only one parent In general angiosperms inherit plastids from the female gamete whereas many gymnosperms inherit plastids from the male pollen Algae also inherit plastids from only one parent The plastid DNA of the other parent is thus completely lost In normal intraspecific crossings resulting in normal hybrids of one species the inheritance of plastid DNA appears to be quite strictly 100 uniparental In interspecific hybridisations however the inheritance of plastids appears to be more erratic Although plastids inherit mainly maternally in interspecific hybridisations there are many reports of hybrids of flowering plants that contain plastids of the father Approximately 20 of angiosperms including alfalfa Medicago sativa normally show biparental inheritance of plastids 21 DNA damage and repair EditPlastid DNA of maize seedlings is subject to increased damage as the seedlings develop 22 The DNA is damaged in oxidative environments created by photo oxidative reactions and photosynthetic respiratory electron transfer Some DNA molecules are repaired while DNA with unrepaired damage appears to be degraded to non functional fragments DNA repair proteins are encoded by the cell s nuclear genome but can be translocated to plastids where they maintain genome stability integrity by repairing the plastid s DNA 23 As an example in chloroplasts of the moss Physcomitrella patens a protein employed in DNA mismatch repair Msh1 interacts with proteins employed in recombinational repair RecA and RecG to maintain plastid genome stability 24 Origin EditPlastids are thought to be endosymbiotic cyanobacteria The primary endosymbiotic event of the Archaeplastida is hypothesized to have occurred around 1 5 billion years ago 25 and enabled eukaryotes to carry out oxygenic photosynthesis 26 Three evolutionary lineages in the Archaeplastida have since emerged in which the plastids are named differently chloroplasts in green algae and or plants rhodoplasts in red algae and muroplasts in the glaucophytes The plastids differ both in their pigmentation and in their ultrastructure For example chloroplasts in plants and green algae have lost all phycobilisomes the light harvesting complexes found in cyanobacteria red algae and glaucophytes but instead contain stroma and grana thylakoids The glaucocystophycean plastid in contrast to chloroplasts and rhodoplasts is still surrounded by the remains of the cyanobacterial cell wall All these primary plastids are surrounded by two membranes The plastid of photosynthetic Paulinella species is often referred to as the cyanelle or chromatophore and had a much more recent endosymbiotic event about 90 140 million years ago it is the only known primary endosymbiosis event of cyanobacteria outside of the Archaeplastida 17 18 The plastid belongs to the PS clade of the cyanobacteria genera Prochlorococcus and Synechococcus which is a different sister clade to the plastids belonging to the Archaeplastida 4 5 In contrast to primary plastids derived from primary endosymbiosis of a prokaryoctyic cyanobacteria complex plastids originated by secondary endosymbiosis in which a eukaryotic organism engulfed another eukaryotic organism that contained a primary plastid 27 When a eukaryote engulfs a red or a green alga and retains the algal plastid that plastid is typically surrounded by more than two membranes In some cases these plastids may be reduced in their metabolic and or photosynthetic capacity Algae with complex plastids derived by secondary endosymbiosis of a red alga include the heterokonts haptophytes cryptomonads and most dinoflagellates rhodoplasts Those that endosymbiosed a green alga include the euglenids and chlorarachniophytes chloroplasts The Apicomplexa a phylum of obligate parasitic protozoa including the causative agents of malaria Plasmodium spp toxoplasmosis Toxoplasma gondii and many other human or animal diseases also harbor a complex plastid although this organelle has been lost in some apicomplexans such as Cryptosporidium parvum which causes cryptosporidiosis The apicoplast is no longer capable of photosynthesis but is an essential organelle and a promising target for antiparasitic drug development Some dinoflagellates and sea slugs in particular of the genus Elysia take up algae as food and keep the plastid of the digested alga to profit from the photosynthesis after a while the plastids are also digested This process is known as kleptoplasty from the Greek kleptes thief Plastid development cycle Edit An illustration of the stages of inter conversion in plastids In 1977 J M Whatley proposed a plastid development cycle which said that plastid development is not always unidirectional but is instead a complicated cyclic process Proplastids are the precursor of the more differentiated forms of plastids as shown in the diagram to the right 28 See also EditMitochondrion Organelle in eukaryotic cells responsible for respiration Cytoskeleton Network of filamentous proteins that forms the internal framework of cellsNotes Edit Sometimes Ernst Haeckel is credited to coin the term plastid but his plastid includes nucleated cells and anucleated cytodes 7 and thus totally different concept from the plastid in modern literature References Edit Sato N 2006 Origin and Evolution of Plastids Genomic View on the Unification and Diversity of Plastids In Wise RR Hoober JK eds The Structure and Function of Plastids Advances in Photosynthesis and Respiration Vol 23 Springer Netherlands pp 75 102 doi 10 1007 978 1 4020 4061 0 4 ISBN 978 1 4020 4060 3 Moore KR Magnabosco C Momper L Gold DA Bosak T Fournier GP 2019 An Expanded Ribosomal Phylogeny of Cyanobacteria Supports a Deep Placement of Plastids Frontiers in Microbiology 10 1612 doi 10 3389 fmicb 2019 01612 PMC 6640209 PMID 31354692 Vries Jan de Gould Sven B 2018 01 15 The monoplastidic bottleneck in algae and plant evolution Journal of Cell Science 131 2 jcs203414 doi 10 1242 jcs 203414 ISSN 0021 9533 PMID 28893840 a b Marin Birger Nowack Eva CM Glockner Gernot Melkonian Michael 2007 06 05 The ancestor of the Paulinella chromatophore obtained a carboxysomal operon by horizontal gene transfer from a Nitrococcus like g proteobacterium BMC Evolutionary Biology 7 85 doi 10 1186 1471 2148 7 85 PMC 1904183 PMID 17550603 a b Ochoa de Alda Jesus A G Esteban Rocio Diago Maria Luz Houmard Jean 2014 01 29 The plastid ancestor originated among one of the major cyanobacterial lineages Nature Communications 5 1 4937 Bibcode 2014NatCo 5 4937O doi 10 1038 ncomms5937 ISSN 2041 1723 PMID 25222494 Schimper A F W 1882 Ueber die Gestalten der Starkebildner und Farbkorper Botanisches Centralblatt 12 5 175 178 Haeckel E 1866 Morphologische Individuen erster Ordnung Plastiden oder Plasmastucke in his Generelle Morphologie der Organismen Bd 1 pp 269 289 Picozoans Are Algae After All Study The Scientist Magazine Kolattukudy P E 1996 Biosynthetic pathways of cutin and waxes and their sensitivity to environmental stresses pp 83 108 in Plant Cuticles G Kerstiens ed BIOS Scientific publishers Ltd Oxford a b Wise Robert R 2006 1 The Diversity of Plastid Form and Function Advances in Photosynthesis and Respiration Vol 23 Springer pp 3 26 doi 10 1007 978 1 4020 4061 0 1 ISBN 978 1 4020 4060 3 Wicke S Schneeweiss GM dePamphilis CW Muller KF Quandt D 2011 The evolution of the plastid chromosome in land plants gene content gene order gene function Plant Molecular Biology 76 3 5 273 297 doi 10 1007 s11103 011 9762 4 PMC 3104136 PMID 21424877 Wicke S Naumann J 2018 Molecular evolution of plastid genomes in parasitic flowering plants Advances in Botanical Research 85 315 347 doi 10 1016 bs abr 2017 11 014 ISBN 9780128134573 a b Plants Without Plastid Genomes The Scientist Retrieved 2015 09 26 Barbrook AC Howe CJ Purton S February 2006 Why are plastid genomes retained in non photosynthetic organisms Trends in Plant Science 11 2 101 8 doi 10 1016 j tplants 2005 12 004 PMID 16406301 DNA of Giant Corpse Flower Parasite Surprises Biologists April 2021 Viola R Nyvall P Pedersen M July 2001 The unique features of starch metabolism in red algae Proceedings Biological Sciences 268 1474 1417 22 doi 10 1098 rspb 2001 1644 PMC 1088757 PMID 11429143 a b Lhee Duckhyun Ha Ji San Kim Sunju Park Myung Gil Bhattacharya Debashish Yoon Hwan Su 2019 02 22 Evolutionary dynamics of the chromatophore genome in three photosynthetic Paulinella species Scientific Reports Scientific Reports 9 1 2560 doi 10 1038 s41598 019 38621 8 PMC 6384880 PMID 30796245 a b Gabr Arwa Grossman Arthur R Bhattacharya Debashish 2020 05 05 Palenik B ed Paulinella a model for understanding plastid primary endosymbiosis Journal of Phycology Wiley 56 4 837 843 doi 10 1111 jpy 13003 ISSN 0022 3646 PMC 7734844 PMID 32289879 Sanchez Baracaldo Patricia Raven John A Pisani Davide Knoll Andrew H 2017 09 12 Early photosynthetic eukaryotes inhabited low salinity habitats Proceedings of the National Academy of Sciences 114 37 E7737 E7745 Bibcode 2017PNAS 114E7737S doi 10 1073 pnas 1620089114 ISSN 0027 8424 PMC 5603991 PMID 28808007 Luis Delaye Cecilio Valadez Cano Bernardo Perez Zamorano 15 March 2016 How Really Ancient Is Paulinella Chromatophora PLOS Currents 8 doi 10 1371 CURRENTS TOL E68A099364BB1A1E129A17B4E06B0C6B ISSN 2157 3999 PMC 4866557 PMID 28515968 Wikidata Q36374426 Zhang Q March 2010 Why does biparental plastid inheritance revive in angiosperms Journal of Plant Research 123 2 201 6 doi 10 1007 s10265 009 0291 z PMID 20052516 S2CID 5108244 Kumar RA Oldenburg DJ Bendich AJ December 2014 Changes in DNA damage molecular integrity and copy number for plastid DNA and mitochondrial DNA during maize development Journal of Experimental Botany 65 22 6425 39 doi 10 1093 jxb eru359 PMC 4246179 PMID 25261192 Oldenburg DJ Bendich AJ 2015 DNA maintenance in plastids and mitochondria of plants Frontiers in Plant Science 6 883 doi 10 3389 fpls 2015 00883 PMC 4624840 PMID 26579143 Odahara M Kishita Y Sekine Y August 2017 MSH1 maintains organelle genome stability and genetically interacts with RECA and RECG in the moss Physcomitrella patens The Plant Journal 91 3 455 465 doi 10 1111 tpj 13573 PMID 28407383 Ochoa de Alda JA Esteban R Diago ML Houmard J September 2014 The plastid ancestor originated among one of the major cyanobacterial lineages Nature Communications 5 4937 Bibcode 2014NatCo 5 4937O doi 10 1038 ncomms5937 PMID 25222494 Hedges SB Blair JE Venturi ML Shoe JL January 2004 A molecular timescale of eukaryote evolution and the rise of complex multicellular life BMC Evolutionary Biology 4 2 doi 10 1186 1471 2148 4 2 PMC 341452 PMID 15005799 Chan CX Bhattachary D 2010 The Origin of Plastids Nature Education 3 9 84 Whatley Jean M 1978 A Suggested Cycle of Plastid Developmental Interrelationships The New Phytologist 80 3 489 502 doi 10 1111 j 1469 8137 1978 tb01581 x ISSN 0028 646X JSTOR 2431207 Further reading EditHanson MR Kohler RH A Novel View of Chloroplast Structure Plant Physiology Online Archived from the original on 2005 06 14 Wycliffe P Sitbon F Wernersson J Ezcurra I Ellerstrom M Rask L October 2005 Continuous expression in tobacco leaves of a Brassica napus PEND homologue blocks differentiation of plastids and development of palisade cells The Plant Journal 44 1 1 15 doi 10 1111 j 1365 313X 2005 02482 x PMID 16167891 Birky CW 2001 The inheritance of genes in mitochondria and chloroplasts laws mechanisms and models PDF Annual Review of Genetics 35 125 48 doi 10 1146 annurev genet 35 102401 090231 PMID 11700280 Archived from the original PDF on 2010 06 22 Retrieved 2009 03 01 Chan CX Bhattacharya D 2010 The origins of plastids Nature Education 3 9 84 Bhattacharya D ed 1997 Origins of Algae and their Plastids New York Springer Verlag Wein ISBN 978 3 211 83036 9 Gould SB Waller RF McFadden GI 2008 Plastid evolution Annual Review of Plant Biology 59 491 517 doi 10 1146 annurev arplant 59 032607 092915 PMID 18315522 S2CID 30458113 Keeling PJ March 2010 The endosymbiotic origin diversification and fate of plastids Philosophical Transactions of the Royal Society of London Series B Biological Sciences 365 1541 729 48 doi 10 1098 rstb 2009 0103 PMC 2817223 PMID 20124341 External links EditTransplastomic plants for biocontainment biological confinement of transgenes Co extra research project on coexistence and traceability of GM and non GM supply chains Tree of Life Eukaryotes Retrieved from https en wikipedia org w index php title Plastid amp oldid 1127908963, wikipedia, wiki, book, books, library,

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