Academic Voices A Multidisciplinary Journal Volume 1, N0. 1, 2011

POSITION OF CYANOBACTERIA AND ALGAE IN ORIGIN OF LIFE Vishwanath Prasad Department of Botany

Abstract Our beautiful planet, the earth was originated 4.5 billion years ago in our solar system. Between 3.5 – 4.0 billion years ago, after several events of chemical evolution and modifi cation in the earth's atmosphere, the fi rst life, amino acid and nucleic acid, called ecobiont or protobiont, was originated in abiogenesis phase and started protobiology phase. The life has evolved into three domains: age of Eobacteria, Cyanobacteria and Eukaryotes which ultimately evolve into land plants. The purpose of the this article is to add some recent information about origin of life and position of cyanobacteria in the evolution of higher plants.

Keywords Origin, life, Ecobiont, Cyanobacteria, algae.

Introduction from each other by immense large empty space. Spiral galaxy, our closest neighbour Life is very mysterious gift of nature on called the Andromeda Nebula, located at this beautiful planet, earth. The origin of about 28 million light years from the earth is life and even earth in the universe is still the cluster of galaxies. Average galaxy consists mysterious and complex. The earth is a tiny of some 100 billion stars. Our sun is one of the part of the Universe. The theoretical rough middle size star and our earth is a middle size estimate reveals that the universe consists planet of the solar system (Carl Zeiss, 2005). about 50 billion galaxies. Astrophysics study The earth was probably formed about 4.5x109 of the universe from the earth using the art years ago, however, the oldest terrestrial rocks technology observation reveals the presence found to date are about 3.5x109 years old or so. of two galaxies, elliptical and spiral, separated ( Margulis et al, 1976).

94 anoxic photosynthesis generated themost Gyrs ago whenthe cells origin of and This Age ofEobacteria Eukaryotes.of Eobacteriaof , age Cyanobacteriaof and age evolvedintofollowing three life: ages age of revolution (Cavalier –Smith,2006),life has Glycobacterial revolutionNeomuran and Under two revolutionary periods, Three – phases history lifeof some heterotrophic anaerobic bacteria. formsliving this onplanet wereprobably biological evidences suggest that the organisms .Presently, the geological and and coacervates arebiological the origin of called eobionts orprotobionts. The eobionts life).the Thus, organisms are accordingly eobiology (dawn lifeof ) or protobiology ( originated nucleic acid. This phage is called wasthe amino origin of acidwhichheating on evolved into biological entities. This phage toled moleculesreplicating which gradually recognition, interaction etc. It could h and under go the processes selectivity, of called coacervates,may absorb water, swell the Nature h Itwithoutlife. wasphase abiogenesis. called of production complex of organic compounds water.Inthe there early earth, period of were down su as sources energy. of Later, the earth cooled ultraviolet of radiations andelectric discharge amino acids werein underformed the ago andsimpler organic compoundslike probably between 3500-4000 million years oc have Many events chemicalevolution of arelikely to preponderance hydrogen of (Oparin,1964). nitrogenammonia, andwater vapour with atmosphere was anoxicmethane, andconsist of Lifeprobably originated whenthe earth's Origin Lifeof : fi rstbiological entity. The droplet fi rst phase began before 2.9-2.8 curred in the prebiontic atmosphere, ffi ave inl t poie ol f liquid of pools provide to ciently made severalintrials creating fl uence fi fi rst rst ave

using hydrogen or H anoxygenic photosynthesis, chaemosynthesis ester phospholipid membranes. They h negibacteria with cell boundedby two acyl primitive prokaryote chlorobacteria, the cyanobacteria h Unlikemost otherbacteria,the groups of theAge cyanobacteria2006) (Schopf, of Prokaryotes and the later this half of Eon, was beperiod couldproperly termed asAge of membrane, therefore, thePrecambrian where asposibacteria consists only one surface always two distinct lipid surface membranes The Eobacteria and Cyanobacteria both h and architects atmosphere. of also called anaerobiczones. Therefore, cyanobacteria are biosphere was di predominantlyfed ecosystem the and years ago, cyanobacterialphotosynthesis During this age, between 2.8–0.9billion an oxygenic age called ageCyanobacteria. of and the glycobacterial revolutioninitiated dramatically transformed the earth's surface the cellularinnovationmicrobialradiation and After the Chlorobacterial or Eobacterial age, Age ofCyanobacteria Gribaldo and Brochier, 2006) and the Euryarchaeota. (Woese et. al., 1990; into twomajor phyla, theCrenarchaeota genomicsphylogenetic and datais diversi molecular,and eukaryote, thebasis on of in additiontolife, bacteriathird dormain of alsoChlorobacterial called age.Archaea a with origination of glycobacteriaintothen and chlorobacteria negibacteria, eurybacteria, posibacteria, to Many cyanobacteriah phenotypemorphological few with exceptions. cyanobacteria than Ecoli, Bacillus and smaller size is apparently larger in most complex e popular heterotrophic bacteria. They h long generationtimes as comparedto the ffi in DArpi sses Te genome The systems. DNA-repair cient fi xtransition carbon. Then, occurredin Cyanobacteria and Algae inorigin oflife fi rst oxygenproducing organism ff ave a greater div ave agreater erentiatedinto aerobic and fl agella in cells. This is 2 s as ave exter hydrogen donor ersity of emely fi fi rst ave ave ave ed 95 Academic Voices, Vol. 1, N0. 1, 2011 96 Academic Voices, Vol. 1, N0. 1, 2011 V. Prasad millions of years.millions of Theprebiontic atmosphere byconservedthe evolutionaryprocess over fossils because they h Proteinsnucleic andacids are dividing type (Castenholz, 1992). billion daltons in more complex ca 1.6billion daltons in unicellular type to 8.6 about128 strains cyanobacteria of ranges from unicellular cyanobacteria. The genome size of a 4000 Myr. 3000 Myr. 2000 Myr. 1000 Myr 1000                       Present g o

3.1 Gyr 2.1 Gyr 3.8 Gyr Oldest rocks 3.8 Gyr Oldest 3.5 Gyr 2.8 Gyr earth 2.4 Gyr snowball 2.3 Gyr 1.5 Gyr 0.9 Gyr 0.543 Gyr 0.253 Gyr 0.065 Gyr Oxygen-rich atmosphere atmosphere Oxygen-rich Fig 1.Origin Lifeof (Source :Cavalier –Smith,2006)

ave Photosynthesis Photosynthesis Oxygenic (Gyr: Billion years; Myr: Million years ) atmosphericoxygenation mass extinction Eukaryotes, archaebacteria Eukaryotes, archaebacteria Methanogenesis Snow ballearth Land Plants been dynamically

Possible cellular fossils fi lamentous dinosaurs diatoms diatoms dinosaurs dinoflagellates dinoflagellates atmosphere anoxic Cyanobacteria Cyanobacteria Actinobacteria Actinobacteria 1980) arginineof andaspartic(Kumar, acid. et.al., cyanobacteria contains equimolarproportions nitrogenase. The cyanophycin granulein heterocysts, to protect the oxygenlabile– in cyanobacteria. Theyh cyanogens, nitrites etc h nitrogenase enzymes acetylene, cyanide, was highly reducing and hence hydrogenase, NEOPROTEROZOIC NEOPROTEROZOIC PHANEROZOIC PHANEROZOIC ARCHAEN HADEAN PALAEOPROTEROZOIC PALAEOPROTEROZOIC GLYCOBACTERIAL REVOLUTION NEOMURAN REVOLUTION REVOLUTION NEOMURAN MID-PROTEROZOIC ave high pr ave high Age ofCyanobacteria Age of eukaryotes Age ofeukaryotes ave a novel novel ave a Age of Eobacteria Age ofEobacteria No evidenceforlife Origin oflife obability device,

Themajorlineagesthe algae of arethe arethe sourceGlaucophyte of simple plastids. Prochlorophyta 1976).Cyanobacteria (Lewin, which is supported by the discovery theof cyanobacterial origin dueto endosymbiosis The evolution is green of plastid of algal warming. snow ballEarth episode by slight global attributed methanogenesis and triggered to ultraviolet, the Arachean organic carbon and Archaebacteria. During720Myr ago, due another age started calledageEukaryotes of planktons,Neomuranof during revolution the ozonelayer later and o.9Gyr ago afterrise The cyanobacterial oxygenliberation grew Age ofEukaryote   unimembrana Fig 2. Tree Lifeof emphasizing major revolution (Source :Cavalier –Smith,2006) Neomur 1. 2.   Surfa Negibacteria surface ce   0.9 Gyrago Eukaryotes membrane membranes Glycobacterial Glycobacterial Neomuran revolution 0.9 Gyrago revolution 2.8 Gyrago   hyperthermophily Arch a Ja Bhattacharya1998., Yin-lorgMedlin, and and higher land plants (Kenrick and Crane, 1997; including Bryophytes, Pteridophytes, and and developmentterrestrial ecosystems of with land plants and initiated the evolution originated. Theyh diversi From(Hoek2009). the et.al., greenlineage Now, the algae may be classi Haptophyta, Cryptophyta and Dinophyta. Euglenophyta, Chlorarachniophyta, Chlorophyta, Rhodophyta, Glaucophyta, have a have The eukaryoticphyla that existtoday, and 15 divisions (Prasad, 2010). e ff ba ery, 1999). cteri Cyanobacteria and Algae inorigin oflife eg. Cyanobacteria eg. Cyanobacteria Glycobacteria membrane Outer fi cation the Charophytes h 3.5 Gyrago eg. Chloroflexus Eobacteria fan–shaped phylogeneticfan–shaped evolution a Oxygen Oxygen

C o l Methanogenesis Methanogenesis o nize s nize ave several ave several o fi il. il. ed into 2 empires Eubacteria similarities ave

97 Academic Voices, Vol. 1, N0. 1, 2011 98 Academic Voices, Vol. 1, N0. 1, 2011 V. Prasad developmentplants.theland of charophytesinitiatedthe evolution and mayor algae.Thelineases of algae,especially prochlorphytes, glaucophytes and other age onthe eareth. The started origin of billion years ago,theinitiated oxygenic glycobacterial revolution between 2.8-0.9 Cyanobacteria, Ecobacteria, cyanobacteriaEukaryotes. and lifehas evolved into three domains:age of the aminonucleicform of acidand acid.The ago, originated in in abiogenesis phase in First of all, life between 3.5-4.0billion years Conclusion Fig 3. Tree Life of (Bhatacharya and Medlin, 1998;Hoek et. al., 2009) fi rt httoh, during phototrophs, rst Cavalier- Smith, T. (2006).Cell evolution and Castenholz, R.W. (1992). Species usage, Carl Zeiss, A.G. (2005).Black Hole in Bhattacharya, D. &Medlin, L.(1998). Algal References Trans. R.Soc. B earth history: stasis and revolution. J. Phycol. concept andevolutionthein cyanobacteria. 16,10-11. the Holmberg IIGalaxy. Physiol. 116,9-15. PhylogenyPlantPlants. Land andorigin of 28,737-745. . 361,969-1006. Innovation Phil. ,

Lewin, R.A.(1976).ProchlorophytaLewin, as a Kumar, H.D., Kumar, A., Rai,L.C.,Gour, G.P. & Kenrick, P. &Crane ,P. R.(1997). The Origin Hoek, V. C.,Mann, D.G. &Jahns, H.(2009). Gribaldo, S.&Brochier, A.C. (2006). The Email: 2002(Birgunj). He wasoneoftheconvenorsNationalSeminaron “Recent AdvancesinPlantScience Sciences (RESIS),BirgunjandChiefEditorofJournalResearch SocietyofIntegratedSciences. UV-B andClimateChange.HeistheImmediatePastPresident ofResearchSocietyIntegrated and internationaljournals.HisareasofinterestincludeAlgalPhysiology,Photobiology, Hindu University(India).Tohiscredit,hehaspublishedseveralarticlesinacclaimednational where hehasbeenteachingforthelastthirtythreeyears.HeisadoctoratefromBanaras Vishwanath PrasadisanAssociateProfessorofBotanyinThakurRamMultipleCampus,Birgunj The Author 261, 9697–98. newproposed division algae. of centre ,Bombay, India. the Universe', Bhabha Atomic Research and Evolution Lifeof and intelligence in paperpresentedin a workshop'Origin on cyanobacteria inthe continuumofLife Ahluwalia,(1980). A.S. Nature and early evolutionplantsland. on of Delhi: Cambridge University Press. Algae : An introduction to Phycology. 1022. theof art. origin andevolutionArchaea: a of state [email protected] . 389,33 –39. Phil. Trans. R.Soc. B Unique positionof

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