scholarly journals The endosymbiotic origin, diversification and fate of plastids

2010 ◽  
Vol 365 (1541) ◽  
pp. 729-748 ◽  
Author(s):  
Patrick J. Keeling

Plastids and mitochondria each arose from a single endosymbiotic event and share many similarities in how they were reduced and integrated with their host. However, the subsequent evolution of the two organelles could hardly be more different: mitochondria are a stable fixture of eukaryotic cells that are neither lost nor shuffled between lineages, whereas plastid evolution has been a complex mix of movement, loss and replacement. Molecular data from the past decade have substantially untangled this complex history, and we now know that plastids are derived from a single endosymbiotic event in the ancestor of glaucophytes, red algae and green algae (including plants). The plastids of both red algae and green algae were subsequently transferred to other lineages by secondary endosymbiosis. Green algal plastids were taken up by euglenids and chlorarachniophytes, as well as one small group of dinoflagellates. Red algae appear to have been taken up only once, giving rise to a diverse group called chromalveolates. Additional layers of complexity come from plastid loss, which has happened at least once and probably many times, and replacement. Plastid loss is difficult to prove, and cryptic, non-photosynthetic plastids are being found in many non-photosynthetic lineages. In other cases, photosynthetic lineages are now understood to have evolved from ancestors with a plastid of different origin, so an ancestral plastid has been replaced with a new one. Such replacement has taken place in several dinoflagellates (by tertiary endosymbiosis with other chromalveolates or serial secondary endosymbiosis with a green alga), and apparently also in two rhizarian lineages: chlorarachniophytes and Paulinella (which appear to have evolved from chromalveolate ancestors). The many twists and turns of plastid evolution each represent major evolutionary transitions, and each offers a glimpse into how genomes evolve and how cells integrate through gene transfers and protein trafficking.

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Richard G Dorrell ◽  
Gillian Gile ◽  
Giselle McCallum ◽  
Raphaël Méheust ◽  
Eric P Bapteste ◽  
...  

Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid-targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid-targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.


2017 ◽  
Vol 24 (2) ◽  
pp. 118-125 ◽  
Author(s):  
Rashmi Chandra ◽  
Roberto Parra ◽  
Hafiz M. N. Iqbal

1958 ◽  
Vol 42 (2) ◽  
pp. 243-250 ◽  
Author(s):  
G. C. McLeod

Action spectra for delayed light production by several algae were determined from 250 to 750 mµ incident light. In the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. Blue-green algae had a maximum at 620 mµ, red algae at 550 mµ, whereas green and brown algae have action spectra corresponding to chlorophyll and carotenoid absorption. In the ultraviolet portion of the spectrum delayed light is emitted by algae down to 250 mµ incident light. The action spectra of the different algae are not alike in the ultraviolet portion of the spectrum. This indicates that pigments other than chlorophyll must be sensitizing or shielding the algae in the ultraviolet region.


2021 ◽  
Vol 58 (1) ◽  
pp. 33-42
Author(s):  
M Jeya Bharathi ◽  
M Raju ◽  
S Elamathi

Rice is a prime food crop for Asian countries. Wet land rice cultivation contributes maximum grain yield than dry land rice. Cauvery delta is a predominant area for rice cultivation in Tamil Nadu. Green algae growth during Kuruvai (June -August) season is a serious problem in wet land rice. These algae growth create anaerobic condition and prevent rice root respiration. The entire rice root was uprooted and floated on the stagnated water during initial stage. There is no preliminary study for green algae control in rice field. Soil and water samples were collected and analyzed for the nature of occurrence. Laboratory and field experiments were conducted to find out the remedial measures. The results of soil and water sample analysis showed that use of bore well water and dumping of phosphatic fertilizers leads to salt accumulation which favours the green algal growth. The results of the laboratory experiment revealed that the CuSO4 londox power, propiconazole and hexaconazole showed moderate inhibition on 5th day after treatment. The findings from field experiment indicated that use of conoweeder, alternate wetting and drying and CuSo4 drenching @ of 2.5 kg/ha when green algae appearance has just noticed or 5.0 kg/ha when severe growth occurred was effective in managing the green algae. Among all measures, alternate wetting and drying is the best management practices. CuSO4 drenching reduces around 70% of the growth. Even though CuSO4 react negatively with algae growth, soil pH changes and salt concentration play a major role on the CuSO4 action towards green algae. In order to maintain soil health condition, biofertilizer application, crop rotation, green manure trampling to be practised to recover the soil from alkaline pH, removal of accumulated salt and to control the algae growth using CuSO4.


2020 ◽  
Vol 1 (1) ◽  
pp. 24-31
Author(s):  
Elvi Kustiyah ◽  
Bungaran Saingin ◽  
Hernowo Widodo ◽  
Viriya Piti

 Indonesia has millions island and big part of Indonesia is sea that is rich in marine biological resources and has the potential to be developed and optimized. One of the abundant marine resources in Indonesia is algae. Algae are plant-like protists. Algae have several important compounds, including protein, carbohydrates, fats, minerals and other useful elements. Proteins contained in algae have the potential to be used as antioxidants. In this study, the levels of protein in red and green algae were tested by using the lowry method and testing the antioxidant activity of red and green algae extracts using the Diphenylpicrylhydrazyl (DPPH) method. Algae extraction was done by maceration, which is soaking the sample in low temperature with phosphate buffer saline (PBS) pH 7. From the extraction results it can be concluded that the red algae (Rhodophyta) has the highest protein content of 5.115 ± 0.126% and the lowest protein content in green algae (Chloropytha) as big as 1.686 ± 0.430%. And from the results of the antioxidant activity test showed that all positive algae showed antioxidant activity but the green algae (Chlorophyta) had the highest antioxidant activity of 71.5946 ± 0.01612% with IC50 value 1.6114.


REAKTOR ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 27
Author(s):  
M Mawardi ◽  
Edison Munaf ◽  
Soleh Kosela ◽  
Widayanti Wibowo

Karakteristik pemisahan ion Cr3+ dan Cr6+ dalam larutan melalui proses biosorpsi menggunakan biomassa alga hijau Spirogyra subsalsa dengan sistem batch telah diteliti. Dalam pelaksanaannya diawali dengan melakukan analisis kualitatif gugus fungsi dalam biomassa menggunakan instrumen FTIR, kemudian dipelajari karakteristik pengaruh variabel pH awal larutan, ukuran partikel biosorben, kecepatan pengadukan, pengaruh pemanasan biosorben, laju penyerapan, pengaruh konsentrasi larutan ion logam terhadap kapasitas serapan biomassa alga. Berdasarkan spektra spektroskopi FTIR dapat disimpulkan bahwa  biomassa alga hijau S. Subsalsa mengandung gugus-gugus karboksilat, amina, amida, amino, karbonil dan hidroksil, disamping adanya senyawa silikon, belerang dan fosfor. Hasil penelitian yang diperoleh  memperlihatkan bahwa kapasitas biosorpsi sangat dipengaruhi oleh pH larutan, waktu kontak dan konsentrasi awal larutan. Biosorpsi optimum kation Cr3+ terjadi pada pH 4,0 sedangkan ion Cr6+ terjadi pada pH 2,0 kemudian berkurang dejalan dengan naiknya pH larutan. Perhitungan dengan persamaan Isoterm Langmuir diperoleh data kapasitas serapan maksimum biomassa alga S. subsalsa untuk masing-masing ion Cr3+ dan Cr6+ adalah 1,82 mg (0,035 mmol) dan 1,51 mg (0,029 mmol) per gram biomassa kering. Kinetika biosorpsi berlangsung relatif cepat, dimana selama selang waktu 30 menit, masing-masing ion terserap sekitar 95,7%; dan 86,5%. Daya serap biomassa juga dipengaruhi kecepatan pengadukan, sedangkan faktor ukuran partikel dan pemanasan biosorben kurang mempengaruhi daya serap biomassa. Key Word : biosorpsi, spirogyra subsalsa, krom(III), krom(VI), sistem batchAbstract Separation of Ion Chromium(III) and Chromium(IV) In Solution Using Green Algae Biomass Spirogyra subsalsa as Biosorbent. The characteristics of Cr3+andCr6+ ion separation in solution through biosorption process using green algal biomass Spirogyrasubsalsa with batch systems have been investigated. The study began with aqualitative analysis of functional groups in biomass using FTIR instrument, then followed by a study of the characteristics of influences by several variables, such as: the initial pH of the solution,the size of biosorben particles, stirring speed, the effect of heating the biosorben, the rate of absorption, and the effect of metal ion concentration in solution on the absorption capacity of algal biomass. Based on FTIR spectroscopy spectra gave a conclusion that biomass of green algae S.subsalsa contains carboxylate groups, amine, amide, amino, carbonyl and hydroxyl, in addition to silicon, sulfur, and phosphorus compounds. The results showed that the biosorption capacity was strongly influenced by pH, contact time, and initial concentration ofthe solution. The optimum biosorption of Cr3+cation occurred at pH 4.0 while that of Cr6+ions occurred at pH 2.0 and then decreased with the increasing pH of solution. The calculation of Langmuir isotherm equation showed that the maximum absorption capacity of algal biomass S.subsalsa for Cr3+and Cr6+ ion respectively was 1.82mg (0.035 mmol) and 1.51 mg (0.029 mmol) pergram of dry biomass. The kinetics of biosorption took place relatively quick, in which during the 30minutes time interval, each ion was absorbed approximately 95.7%; and 86.5%. The absorptive capacity of biomass was also influenced by stirring speed, while the size of particles and heating biosorben gave lessinfluence to the absorption of biomass.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Max E. Schön ◽  
Vasily V. Zlatogursky ◽  
Rohan P. Singh ◽  
Camille Poirier ◽  
Susanne Wilken ◽  
...  

AbstractThe endosymbiotic origin of plastids from cyanobacteria gave eukaryotes photosynthetic capabilities and launched the diversification of countless forms of algae. These primary plastids are found in members of the eukaryotic supergroup Archaeplastida. All known archaeplastids still retain some form of primary plastids, which are widely assumed to have a single origin. Here, we use single-cell genomics from natural samples combined with phylogenomics to infer the evolutionary origin of the phylum Picozoa, a globally distributed but seemingly rare group of marine microbial heterotrophic eukaryotes. Strikingly, the analysis of 43 single-cell genomes shows that Picozoa belong to Archaeplastida, specifically related to red algae and the phagotrophic rhodelphids. These picozoan genomes support the hypothesis that Picozoa lack a plastid, and further reveal no evidence of an early cryptic endosymbiosis with cyanobacteria. These findings change our understanding of plastid evolution as they either represent the first complete plastid loss in a free-living taxon, or indicate that red algae and rhodelphids obtained their plastids independently of other archaeplastids.


2020 ◽  
Vol 8 (3) ◽  
pp. 7
Author(s):  
Silsia Dorkas Winowoda ◽  
Marina Flora Oktavine Singkoh ◽  
Ratna Siahaan

This study aims to analyze the richness and potential of macroalgae bioactive compounds on the Atep Oki Coast, District of Minahasa, North Sulawesi Province. This research was conducted in October 2019 until January 2020. Sampling used the roaming method in a predetermined location that is Atep Oki tidal/ intertidal coast. Sampling locations are spread over six coordinate points. Macroalgae found on the Atep Oki Coast assessed ten species belonging to three phyla, namely Chlorophyta (green algae), Ochrophyta (brown algae) and Rhodophyta (red algae). Chlorophyta members mean six species. Ochrophyta has members of three species and members of Rhodophyta only one species. The types of macroalgae found on the Atep Oki Coast provide bioactive compounds. Keywords : Macroalgae, Bioactive Compounds, Atep Oki Minahasa CoastAbstrak Penelitian ini bertujuan untuk menganalisis kekayaan jenis dan potensi senyawa bioaktif makroalga di Pesisir Atep Oki, Kabupaten Minahasa, Provinsi Sulawesi Utara. Penelitian ini telah dilaksanakan pada bulan Oktober 2019 sampai Januari 2020. Pengambilan sampel menggunakan metode jelajah di lokasi yang telah ditentukan yaitu pesisir pasang surut/intertidal Atep Oki. Lokasi pengambilan sampel tersebar di enam titik-titik koordinat. Makroalga yang ditemukan di Pesisir Atep Oki berjumlah sepuluh species yang tergolong ke dalam tiga filum yaitu Chlorophyta (alga hijau), Ochrophyta (alga cokelat) dan Rhodophyta (alga merah). Anggota Chlorophyta berjumlah enam species. Ochrophyta memiliki anggota tiga species dan anggota Rhodophyta hanya satu species. Jenis-jenis makroalga yang ditemukan di Pesisir Atep Oki berpotensi menghasilkan senyawa bioaktif. Kata kunci : Makroalga, Senyawa Bioaktif, Pesisir Atep Oki Minahasa


2021 ◽  
Vol 9 (5) ◽  
pp. 543-571
Author(s):  
Ritu Chauhan ◽  
◽  
Abhishek Chauhan ◽  
Ashutosh Tripathi ◽  
Anuj Ranjan ◽  
...  

COVID-19 pandemic has taught the world researchers the urgent need for new sources and novel pharmaceuticals not only for existing diseases but also for both seasonal epidemics and future pandemics. Pharmaceutical drug discoveries for the past fifty years depended deeply on the procedure of empirical transmission of a huge number of pure bioactive compounds to provide new leads. The screening of extracts or isolating compounds is a common way to discover novel biologically active molecules. Most of the valuable Blue-Green algal metabolites are concentrated in their biomass. For existence in nature, Blue-Green algae (BGA) secrete and contain various organic substances like proteins, fatty acids, vitamins, pigments, primary and secondary metabolites, and these compounds are explored for potential biological activities such as antibacterial, antifungal, antiviral (including the anti-SARS-CoV-2 virus that causes COVID-19), anticancer, antioxidant, antidiabetic, protease inhibitory activity, anti-inflammatory activity, etc. Due to their diverse application, pharmaceutical companies have shown commercial interest in the Blue-green algal group for the discovery and development of novel molecules to combat deadly diseases for the benefit of society and mankind. The current review paper highlights and discusses the diverse pharmaceutical potential of laboratory-grown cultures of BGA along with comprehensive and current knowledge on bioactive compounds discovered by researchers globally.


1983 ◽  
Vol 15 (6-7) ◽  
pp. 181-190 ◽  
Author(s):  
George P Slater ◽  
Vivian C Blok

A relationship between blue-green algae and off-flavours in water was reported as early as 1883. Continuing research has shown that two metabolites, geosmin and methylisoborneol are major contributors to unpalatable flavours in water and aquatic organisms. Many instances of the co-occurrence of these two compounds and dense blooms of blue-green algae have been recorded. Cultures of Anabaena, Lyngbya, Osciiiatoria, and Sympioca species have been shown to produce geosmin or methylisoborneol while blooms of Aphanizomenon, Anabaena, Microcystis, Oscillatoria, and Gomphosphaeria have been found in water containing geosmin or the odour of this compound. Actinomycetes have also been shown to produce these two compounds. In addition to geosmin and methylisoborneol, there is evidence that several other blue-green algal metabolites contribute to aquatic taste and odour problems. Among them is β-cyclocitral which has a distinctive tobacco flavour. Blue-green algae produce a variety of organic compounds including hydrocarbons, fatty acids, aromatics, ketones, terpenoids, amines and Sulfides which could contribute to the over-all flavour of water and aquatic organisms.


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