41-959: See list of Millettia species Millettia is a genus of flowering plants in the family Fabaceae . It consists of about 169 species of shrubs, lianas or trees, which are native to tropical and subtropical regions of sub-Saharan Africa, the Indian subcontinent, Indochina, southern China, Malesia , and New Guinea . Typical habitats include tropical rain forest and seasonally-dry lowland and upland forest and forest margins, woodland, thicket, wooded grassland, and secondary vegetation. In 1834, in Prodromus Florae Peninsulae Indiae Orientalis Robert Wight and George Arnott Walker-Arnott describe Millettia as: Calyx cup-shaped, lobed or slightly toothed. Corolla papilionaceous : vexillum recurved, broad, emarginate, glabrous or silky on
82-460: A cyanobiont (cyanobacteria such as Nostoc ) which fix nitrogen for them: Some symbiotic relationships involving agriculturally-important plants are: A method for nitrogen fixation was first described by Henry Cavendish in 1784 using electric arcs reacting nitrogen and oxygen in air. This method was implemented in the Birkeland–Eyde process of 1903. The fixation of nitrogen by lightning
123-399: A nitrogenase enzyme. The overall reaction for BNF is: N 2 + 16ATP + 16H 2 O + 8e + 8H → 2NH 3 +H 2 + 16ADP + 16P i The process is coupled to the hydrolysis of 16 equivalents of ATP and is accompanied by the co-formation of one equivalent of H 2 . The conversion of N 2 into ammonia occurs at a metal cluster called FeMoco , an abbreviation for
164-543: A critical threshold. The specialized heterocyst cell is necessary for the performance of nitrogenase as a result of its sensitivity to ambient oxygen. Nitrogenase consist of two proteins, a catalytic iron-dependent protein, commonly referred to as MoFe protein and a reducing iron-only protein (Fe protein). There are three different iron dependent proteins, molybdenum -dependent, vanadium -dependent, and iron -only, with all three nitrogenase protein variations containing an iron protein component. Molybdenum-dependent nitrogenase
205-447: A low nitrogen content, has been shown to host a diazotrophic community. The bacteria enrich the wood substrate with nitrogen through fixation, thus enabling deadwood decomposition by fungi. Nitrogenases are rapidly degraded by oxygen. For this reason, many bacteria cease production of the enzyme in the presence of oxygen. Many nitrogen-fixing organisms exist only in anaerobic conditions, respiring to draw down oxygen levels, or binding
246-424: A new era of soil science ." In 1901, Beijerinck showed that Azotobacter chroococcum was able to fix atmospheric nitrogen. This was the first species of the azotobacter genus, so-named by him. It is also the first known diazotroph , species that use diatomic nitrogen as a step in the complete nitrogen cycle . Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by
287-451: A second metal (usually molybdenum , but sometimes vanadium ). Some nitrogen-fixing bacteria have symbiotic relationships with plants , especially legumes , mosses and aquatic ferns such as Azolla . Looser non-symbiotic relationships between diazotrophs and plants are often referred to as associative, as seen in nitrogen fixation on rice roots. Nitrogen fixation occurs between some termites and fungi . It occurs naturally in
328-446: Is a chemical process by which molecular dinitrogen ( N 2 ) is converted into ammonia ( NH 3 ). It occurs both biologically and abiologically in chemical industries . Biological nitrogen fixation or diazotrophy is catalyzed by enzymes called nitrogenases . These enzyme complexes are encoded by the Nif genes (or Nif homologs ) and contain iron , often with
369-408: Is a required precursor to fertilizers , explosives , and other products. The Haber process requires high pressures (around 200 atm) and high temperatures (at least 400 °C), which are routine conditions for industrial catalysis. This process uses natural gas as a hydrogen source and air as a nitrogen source. The ammonia product has resulted in an intensification of nitrogen fertilizer globally and
410-532: Is a very similar natural occurring process. The possibility that atmospheric nitrogen reacts with certain chemicals was first observed by Desfosses in 1828. He observed that mixtures of alkali metal oxides and carbon react with nitrogen at high temperatures. With the use of barium carbonate as starting material, the first commercial process became available in the 1860s, developed by Margueritte and Sourdeval. The resulting barium cyanide reacts with steam, yielding ammonia. In 1898 Frank and Caro developed what
451-566: Is credited with supporting the expansion of the human population from around 2 billion in the early 20th century to roughly 8 billion people now. Much research has been conducted on the discovery of catalysts for nitrogen fixation, often with the goal of lowering energy requirements. However, such research has thus far failed to approach the efficiency and ease of the Haber process. Many compounds react with atmospheric nitrogen to give dinitrogen complexes . The first dinitrogen complex to be reported
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#1732781188480492-442: Is dependent on many factors, including the legume and air and soil conditions. For example, nitrogen fixation by red clover can range from 50 to 200 lb/acre (56 to 224 kg/ha). The ability to fix nitrogen in nodules is present in actinorhizal plants such as alder and bayberry , with the help of Frankia bacteria. They are found in 25 genera in the orders Cucurbitales , Fagales and Rosales , which together with
533-476: Is first mentioned. The authors named the genus after Charles Millett, incorrectly referring to him as Dr. Charles Millett. Charles Millett of the East India Company has often been confused with Charles Millet, a French ichthyologist , who was active around the same time. In addition J. A. Millet, a French botanist from the 18th century, is often misattributed as the source. Robert Sweet states that
574-408: Is genetically regulated, and the activity of the protein complex is dependent on ambient oxygen concentrations, and intra- and extracellular concentrations of ammonia and oxidized nitrogen species (nitrate and nitrite). Additionally, the combined concentrations of both ammonium and nitrate are thought to inhibit N Fix , specifically when intracellular concentrations of 2- oxoglutarate (2-OG) exceed
615-571: Is known as the Frank–Caro process to fix nitrogen in the form of calcium cyanamide . The process was eclipsed by the Haber process , which was discovered in 1909. The dominant industrial method for producing ammonia is the Haber process also known as the Haber-Bosch process. Fertilizer production is now the largest source of human-produced fixed nitrogen in the terrestrial ecosystem . Ammonia
656-796: Is no conclusive agreement on which form of nitrogenase arose first. Diazotrophs are widespread within domain Bacteria including cyanobacteria (e.g. the highly significant Trichodesmium and Cyanothece ), green sulfur bacteria , purple sulfur bacteria , Azotobacteraceae , rhizobia and Frankia . Several obligately anaerobic bacteria fix nitrogen including many (but not all) Clostridium spp. Some archaea such as Methanosarcina acetivorans also fix nitrogen, and several other methanogenic taxa , are significant contributors to nitrogen fixation in oxygen-deficient soils. Cyanobacteria , commonly known as blue-green algae, inhabit nearly all illuminated environments on Earth and play key roles in
697-590: Is the most commonly present nitrogenase. The different types of nitrogenase can be determined by the specific iron protein component. Nitrogenase is highly conserved. Gene expression through DNA sequencing can distinguish which protein complex is present in the microorganism and potentially being expressed. Most frequently, the nif H gene is used to identify the presence of molybdenum-dependent nitrogenase, followed by closely related nitrogenase reductases (component II) vnf H and anf H representing vanadium-dependent and iron-only nitrogenase, respectively. In studying
738-485: The Fabales form a nitrogen-fixing clade of eurosids . The ability to fix nitrogen is not universally present in these families. For example, of 122 Rosaceae genera, only four fix nitrogen. Fabales were the first lineage to branch off this nitrogen-fixing clade; thus, the ability to fix nitrogen may be plesiomorphic and subsequently lost in most descendants of the original nitrogen-fixing plant; however, it may be that
779-529: The Indies , China , and Africa , this species has had many traditional names. One of the oldest references in traditional Chinese medicine is in Bencao Gangmu Shiyi ("Supplement to Compendium of Materia Medica ") where is called jixueteng. The Chinese name literally translates to "stem of chicken's blood" which refers to the red resin present in the stems of several climbing legume shrubs. In
820-582: The 1820s-1830s Charles Millett, a plant collector and an official with the East India Company , collected many samples of Millettia while living in Canton and Macao . He sent them to the University of Glasgow 's Botanical Garden. In 1834, Robert Wight and George Arnott Walker-Arnott , both Scottish botanists, published Prodromus Florae Peninsulae Indiae Orientalis where the genus Millettia
861-506: The African species wenge ( M. laurentii De Wild. ) and panga panga or mpande ( M. stuhlmannii Taub. ). The timber is used for flooring, furniture, cabinet work, construction, veneers, joinery, and agricultural implements. Selected species include: List of Millettia species Flowering plants in the legume family Millettia is a large, broadly distributed genus of flowering plants in
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#1732781188480902-606: The World Online . Royal Botanical Gardens Kew . Retrieved 18 September 2023 . Retrieved from " https://en.wikipedia.org/w/index.php?title=List_of_Millettia_species&oldid=1175969531 " Categories : Millettia Lists of plant species Hidden categories: Articles with short description Short description matches Wikidata Articles containing potentially dated statements from September 2023 All articles containing potentially dated statements Nitrogen fixation Nitrogen fixation
943-414: The air by means of NO x production by lightning . Nitrogen fixation is essential to life on Earth because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing organic compounds such as amino acids , polypeptides and proteins , nucleoside triphosphates and nucleic acids . As part of the nitrogen cycle , it is essential for soil fertility and
984-697: The amount of nitrogen fixed in the ocean is at least as much as that on land. The colonial marine cyanobacterium Trichodesmium is thought to fix nitrogen on such a scale that it accounts for almost half of the nitrogen fixation in marine systems globally. Marine surface lichens and non-photosynthetic bacteria belonging in Proteobacteria and Planctomycetes fixate significant atmospheric nitrogen. Species of nitrogen fixing cyanobacteria in fresh waters include: Aphanizomenon and Dolichospermum (previously Anabaena). Such species have specialized cells called heterocytes , in which nitrogen fixation occurs via
1025-577: The back. Stamens diadelphous (9 and 1), the tenth quite distinct. Legume flat, elliptic or lanceolate, pointed, coriaceous, thick margined, wingless indehiscent, 1-2 seeded: valves closely cohering with each other all round the seeds and between them. Twining or arboreous. Leaves very large, unequally pinnated: leaflets opposite, with a setaceous partial stipule at the base of each partial petiole . Racemes axillary, more or less branched and compound. Flowers pretty large, purplish, pedicelled on shortish diverging partial peduncles . Long known to residents of
1066-409: The basic genetic and physiological requirements were present in an incipient state in the most recent common ancestors of all these plants, but only evolved to full function in some of them. In addition, Trema ( Parasponia ), a tropical genus in the family Cannabaceae , is unusually able to interact with rhizobia and form nitrogen-fixing nodules. Some other plants live in association with
1107-561: The carbon and nitrogen cycle of the biosphere . In general, cyanobacteria can use various inorganic and organic sources of combined nitrogen, such as nitrate , nitrite , ammonium , urea , or some amino acids . Several cyanobacteria strains are also capable of diazotrophic growth, an ability that may have been present in their last common ancestor in the Archean eon. Nitrogen fixation not only naturally occurs in soils but also aquatic systems, including both freshwater and marine. Indeed,
1148-654: The correct citation was established as "Pongamia Adans. (1763)". In 1981 a proposal to conserve the genus Millettia and reject the genus Pongamia was proposed in the journal Taxon and was ratified in 1988. Most of the species formerly classed in Pongamia are now included in Millettia , with the exception of Pongamia pinnata . Species are used locally as fuelwood, fish poisons, insecticides, medicine, ornamentals, and nitrogen fixers for soil rehabilitation in agroforestry . Several species are used for timber, including
1189-498: The ecology and evolution of nitrogen-fixing bacteria , the nifH gene is the biomarker most widely used. nif H has two similar genes anf H and vnfH that also encode for the nitrogenase reductase component of the nitrogenase complex. Nitrogenase is thought to have evolved sometime between 1.5-2.2 billion years ago (Ga), although some isotopic support showing nitrogenase evolution as early as around 3.2 Ga. Nitrogenase appears to have evolved from maturase -like proteins, although
1230-410: The function of the preceding protein is currently unknown. Nitrogenase has three different forms ( Nif, Anf, and Vnf ) that correspond with the metal found in the active site of the protein (Molybdenum, Iron, and Vanadium respectively). Marine metal abundances over Earth’s geologic timeline are thought to have driven the relative abundance of which form of nitrogenase was most common. Currently, there
1271-643: The genus Pongamia comes from the Malabar region in India and is derived from the local word Pongam (most likely from the Malayalam language). Pongamia had often been misattributed to Vent. (1803), but it was preceded by "Pongam Adans. (1763)", "Galedupa Lam. (1788)", and "Pungamia Lam. (1796)" and in accordance with the 1994 Tokyo Code of the International Code of Botanical Nomenclature ,
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1312-406: The growth of terrestrial and semiaquatic vegetations , upon which all consumers of those ecosystems rely for biomass . Nitrogen fixation is thus crucial to the food security of human societies in sustaining agricultural yields (especially staple crops ), livestock feeds ( forage or fodder ) and fishery (both wild and farmed ) harvests . It is also indirectly relevant to
1353-548: The iron- molybdenum cofactor. The mechanism proceeds via a series of protonation and reduction steps wherein the FeMoco active site hydrogenates the N 2 substrate. In free-living diazotrophs , nitrogenase-generated ammonia is assimilated into glutamate through the glutamine synthetase /glutamate synthase pathway. The microbial nif genes required for nitrogen fixation are widely distributed in diverse environments. For example, decomposing wood, which generally has
1394-7649: The legume family, Fabaceae . As of September 2023 , there are 169 accepted species in Kew 's Plants of the World Online . Species are found in tropical and subtropical areas throughout the Old World. [REDACTED] Millettia grandis [REDACTED] Millettia peguensis Millettia aboensis (Hook.) Baker Millettia achtenii De Wild. Millettia acuticarinata Baker f. Millettia ahernii Merr. & Rolfe Millettia angustidentata De Wild. Millettia angustistipellata De Wild. Millettia aromatica Dunn Millettia aurea (R.Vig.) Du Puy & Labat Millettia austroyunnanensis Y.Y.Qian Millettia barteri (Benth.) Dunn Millettia bequaertii De Wild. Millettia bipindensis Harms Millettia borneensis Adema Millettia brachycarpa Merr. Millettia brandisiana Kurz Millettia bussei Harms Millettia cabrae De Wild. Millettia caerulea Baker Millettia cana Benth. Millettia capuronii Du Puy & Labat Millettia caudata (Benth.) Baker Millettia chrysamaryssa Adema Millettia chrysophylla Dunn Millettia comosa (Micheli) Hauman Millettia conraui Harms Millettia coruscans Dunn Millettia cubittii Dunn Millettia densiflora Mattapha, Lanors. & Lamxay Millettia dinklagei Harms Millettia diptera Gagnep. Millettia discolor De Wild. Millettia drastica Welw. ex Baker Millettia dubia De Wild. Millettia duchesnei De Wild. Millettia dura Dunn Millettia ebenifera (Bertol.) J.E.Burrows & Lötter Millettia eetveldeana (Micheli) Hauman Millettia elongatistyla J.B.Gillett Millettia elskensii De Wild. Millettia entadoides Z.Wei Millettia eriocarpa Dunn Millettia erythrocalyx Gagnep. Millettia exauriculata Hauman Millettia extensa (Benth.) Benth. ex Baker Millettia ferruginea (Hochst.) Hochst. ex Baker Millettia fruticosa (DC.) Benth. ex Baker Millettia fulgens Dunn Millettia galliflagrans Whitmore Millettia geerinckiana O.Lachenaud Millettia glabra Adema Millettia glaucescens Kurz Millettia goossensii (Hauman) Polhill Millettia gracilis Welw. ex Baker Millettia grandis (E.Mey.) Skeels Millettia griffithii Dunn Millettia griffoniana Baill. Millettia harmandii Gagnep. Millettia harmsiana De Wild. Millettia hedraeantha Harms Millettia hitsika Du Puy & Labat Millettia hockii De Wild. Millettia hylobia Louis ex Hauman Millettia hypolampra Harms Millettia impressa Harms Millettia irvinei Hutch. & Dalziel Millettia kangensis Craib Millettia kennedyi Hoyle Millettia kerrii P.K.Lôc Millettia klainei Dunn Millettia lacus-alberti J.B.Gillett Millettia lane-poolei Dunn Millettia laotica Gagnep. Millettia lasiantha Dunn Millettia lastoursvillensis Pellegr. Millettia laurentii De Wild. Millettia lebrunii Hauman Millettia lecomtei Dunn Millettia lenneoides Vatke Millettia leonensis Hepper Millettia letestui Pellegr. Millettia liberica Jongkind Millettia limbutuensis De Wild. Millettia longipes Perkins Millettia lucens (Scott Elliot) Dunn Millettia lucida Gagnep. Millettia lundensis E.P.Sousa Millettia macrophylla Benth. Millettia macrostachya Collett & Hemsl. Millettia macroura Harms Millettia makondensis Harms Millettia mannii Baker Millettia melanocarpa (Hauman) Adomou Millettia merrillii Perkins Millettia micans Taub. Millettia mildbraedii Harms Millettia mossambicensis J.B.Gillett Millettia multiflora Collett & Hemsl. Millettia nathaliae Du Puy & Labat Millettia nepalensis R.Parker Millettia nigrescens Gagnep. Millettia nudiflora Welw. ex Baker Millettia nutans Welw. ex E.P.Sousa Millettia nyangensis Pellegr. Millettia oblata Dunn Millettia oraria (Hance) Dunn Millettia orientalis Du Puy & Labat Millettia oyemensis Pellegr. Millettia pachyloba Drake Millettia pallens Stapf Millettia paucijuga Harms Millettia peguensis Ali Millettia penduliformis Gagnep. Millettia penicillata Gagnep. Millettia phuwuaensis Mattapha & Suddee Millettia pilosa Hutch. & Dalziel Millettia platyphylla Merr. ex Dunn Millettia principis Gagnep. Millettia psilopetala Harms Millettia pterocarpa Dunn Millettia pubinervis Kurz Millettia puerarioides Prain Millettia puguensis J.B.Gillett Millettia pulchra (Voigt) Kurz Millettia rhodantha Baill. Millettia richardiana (Baill.) Du Puy & Labat Millettia rigens (Craib) Niyomdham Millettia ripicola E.P.Sousa Millettia rubiginosa Wight & Arn. Millettia sacleuxii Dunn Millettia sanagana Harms Millettia sapindifolia T.C.Chen Millettia sapinii De Wild. Millettia schliebenii Harms Millettia semseii J.B.Gillett Millettia sericantha Harms Millettia sericea (Vent.) Wight & Arn. ex Hassk. Millettia solomonensis Verdc. Millettia soyauxii Taub. Millettia splendens Wight & Arn. Millettia stenopetala Hauman Millettia stipellatissima Hauman Millettia stipulata Dunn Millettia stuhlmannii Taub. Millettia subpalmata Dunn Millettia suddeei Mattapha & Tetsana Millettia takou Lorougnon Millettia tanaensis J.B.Gillett Millettia taolanaroensis Du Puy & Labat Millettia tecta (Craib) Mattapha & Chantar. Millettia tenuipes Merr. Millettia tessmannii Harms Millettia tetraptera Kurz Millettia theuszii (Büttner) De Wild. Millettia thollonii Dunn Millettia thonneri De Wild. Millettia thonningii (Schumach. & Thonn.) Baker Millettia ulbrichiana Harms Millettia urophylloides De Wild. Millettia usaramensis Taub. Millettia vankerckhovenii De Wild. Millettia vatkei P.K.Lôc Millettia velutina Dunn Millettia velvetina Adema Millettia versicolor Welw. ex Baker Millettia viridiflora O.Lachenaud Millettia warneckei Harms Millettia wellensii De Wild. Millettia wieringae Adomou Millettia xylocarpa Miq. Millettia zechiana Harms References [ edit ] ^ " Millettia Wight & Arn" . Plants of
1435-492: The manufacture of all nitrogenous industrial products , which include fertilizers , pharmaceuticals , textiles , dyes and explosives . Biological nitrogen fixation was discovered by Jean-Baptiste Boussingault in 1838. Later, in 1880, the process by which it happens was discovered by German agronomist Hermann Hellriegel and Hermann Wilfarth [ de ] and was fully described by Dutch microbiologist Martinus Beijerinck . "The protracted investigations of
1476-473: The nitrogenase enzyme. One type of organelle can turn nitrogen gas into a biologically available form. This nitroplast was discovered in algae . Plants that contribute to nitrogen fixation include those of the legume family — Fabaceae — with taxa such as kudzu , clover , soybean , alfalfa , lupin , peanut and rooibos . They contain symbiotic rhizobia bacteria within nodules in their root systems , producing nitrogen compounds that help
1517-409: The oxygen with a protein such as leghemoglobin . Atmospheric nitrogen is inaccessible to most organisms, because its triple covalent bond is very strong. Most take up fixed nitrogen from various sources. For every 100 atoms of carbon, roughly 2 to 20 atoms of nitrogen are assimilated. The atomic ratio of carbon (C) : nitrogen (N) : phosphorus (P) observed on average in planktonic biomass
1558-475: The plant to grow and compete with other plants. When the plant dies, the fixed nitrogen is released, making it available to other plants; this helps to fertilize the soil . The great majority of legumes have this association, but a few genera (e.g., Styphnolobium ) do not. In many traditional farming practices, fields are rotated through various types of crops, which usually include one consisting mainly or entirely of clover . Fixation efficiency in soil
1599-462: The relation of plants to the acquisition of nitrogen begun by de Saussure , Ville , Lawes , Gilbert and others, and culminated in the discovery of symbiotic fixation by Hellriegel and Wilfarth in 1887." "Experiments by Bossingault in 1855 and Pugh, Gilbert & Lawes in 1887 had shown that nitrogen did not enter the plant directly. The discovery of the role of nitrogen fixing bacteria by Herman Hellriegel and Herman Wilfarth in 1886-1888 would open
1640-767: Was Ru(NH 3 ) 5 ( N 2 ) . Some soluble complexes do catalyze nitrogen fixation. Nitrogen can be fixed by lightning converting nitrogen gas ( N 2 ) and oxygen gas ( O 2 ) in the atmosphere into NO x ( nitrogen oxides ). The N 2 molecule is highly stable and nonreactive due to the triple bond between the nitrogen atoms. Lightning produces enough energy and heat to break this bond allowing nitrogen atoms to react with oxygen, forming NO x . These compounds cannot be used by plants, but as this molecule cools, it reacts with oxygen to form NO 2 , which in turn reacts with water to produce HNO 2 ( nitrous acid ) or HNO 3 ( nitric acid ). When these acids seep into
1681-422: Was originally described by Alfred Redfield, who determined the stoichiometric relationship between C:N:P atoms, The Redfield Ratio, to be 106:16:1. The protein complex nitrogenase is responsible for catalyzing the reduction of nitrogen gas (N 2 ) to ammonia (NH 3 ). In cyanobacteria , this enzyme system is housed in a specialized cell called the heterocyst . The production of the nitrogenase complex