|
Sinorhizobium Meliloti
''Ensifer meliloti'' (formerly ''Rhizobium meliloti'' and ''Sinorhizobium meliloti'') are an aerobic, Gram-negative, and diazotrophic species of bacteria. ''S. meliloti'' are motile and possess a cluster of peritrichous flagella. ''S. meliloti'' fix atmospheric nitrogen into ammonia for their legume symbionts, such as alfalfa. ''S. meliloti'' forms a symbiotic relationship with legumes from the genera ''Medicago'', ''Melilotus'' and ''Trigonella'', including the model legume ''Medicago truncatula''. This symbiosis promotes the development of a plant organ, termed a root nodule. Because soil often contains a limited amount of nitrogen for plant use, the symbiotic relationship between ''S. meliloti'' and their legume hosts has agricultural applications. These techniques reduce the need for inorganic nitrogenous fertilizers. Symbiosis Symbiosis between ''S. meliloti'' and its legume hosts begins when the plant secretes an array of betaines and flavonoids into the rhizosphere: 4,4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agar Plate
An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate will grow into individual colonies, each a clone genetically identical to the individual ancestor organism (except for the low, unavoidable rate of mutation). Thus, the plate can be used either to estimate the concentration of organisms in a liquid culture or a suitable dilution of that culture using a colony counter, or to generate genetically pure cultures from a mixed culture of genetically different organisms. Several methods are available to plate out cells. One technique is known as " streaking". In this technique, a drop of the culture on the end of a thin, sterile loop of wire, sometimes known as an inoculator, is streaked across the surface of the agar leaving organisms behind, a higher number at the beginning of the streak and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a Heterocyclic compound, heterocyclic ring (C, the ring containing the embedded oxygen). This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature, they can be classified into: *flavonoids or bioflavonoids *isoflavonoids, derived from 3-phenylchromone, chromen-4-one (3-phenyl-1,4-benzopyran, benzopyrone) structure *neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyran, benzopyrone) structure The three flavonoid classes above are all ketone-containing compounds and as such, anthoxanthins (flavones and flavonols). This class was the first to be termed bioflavonoids. The terms flavonoid and bioflav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiosome
A symbiosome is a specialised compartment in a host cell that houses an endosymbiont in a symbiotic relationship. The term was first used in 1983 to describe the vacuole structure in the symbiosis between the animal host the '' Hydra'', and the endosymbiont ''Chlorella''. Symbiosomes are also seen in other cnidaria-dinoflagellate symbioses, including those found in coral-algal symbioses. In 1989 the concept was applied to the similar structure found in the nitrogen-fixing root nodules of certain plants. The symbiosome in the root nodules has been much more successfully researched due in part to the complexity of isolating the symbiosome membrane in animal hosts. The symbiosome in a root nodule cell in a plant is an organelle-like structure that has formed in a symbiotic relationship with nitrogen-fixing bacteria. The plant symbiosome is unique to those plants that produce root nodules. The majority of such symbioses are made between legumes and diazotrophic ''Rhizobia'' bacteria. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leghemoglobin
3rd Leghemoglobin (also leghaemoglobin or legoglobin) is an oxygen-carrying phytoglobin found in the nitrogen-fixing root nodules of leguminous plants. It is produced by these plants in response to the roots being colonized by nitrogen-fixing bacteria, termed rhizobia, as part of the symbiotic interaction between plant and bacterium: roots not colonized by '' Rhizobium'' do not synthesise leghemoglobin. Leghemoglobin has close chemical and structural similarities to hemoglobin, and, like hemoglobin, is red in colour. It was originally thought that the heme prosthetic group for plant leghemoglobin was provided by the bacterial symbiont within symbiotic root nodules. However, subsequent work shows that the plant host strongly expresses heme biosynthesis genes within nodules, and that activation of those genes correlates with leghemoglobin gene expression in developing nodules. In plants colonised by ''Rhizobium'', such as alfalfa or soybeans, the presence of oxygen in the roo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosymbiont
An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within", σύν ''syn'' "together" and βίωσις ''biosis'' "living".) Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals and bacterial endosymbionts that provide essential nutrients to insects. There are two types of symbiont transmissions. In horizontal transmission, each new generation acquires free living symbionts from the environment. An example is the nitrogen-fixing bacteria in certain plant roots. Vertical transmission takes place when the symbiont is transferred directly from parent to offspring. It is also possible for both to be involved in a mixed-mode transmission, where symbionts are transferred vertically for some generation bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizobia
Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are gram negative, motile, non- sporulating rods. Rhizobia are a "group of soil bacteria that infect the roots of legumes to form root nodules". Rhizobia are found in the soil and after infection, produce nodules in the legume where they fix nitrogen gas (N2) from the atmosphere turning it into a more readily useful form of nitrogen. From here, the nitrogen is exported from the nodules and used for growth in the legume. Once the legume dies, the nodule breaks down and releases the rhizobia back into the soil where they can live individually or reinfect a new legume host. History The first known species of rhizobia, ''Rhizobium leguminosarum'', was identified in 1889, and all further species were initially placed in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nod Factor
Nod factors (nodulation factors or NF), are signaling molecules produced by soil bacteria known as rhizobia in response to flavonoid exudation from plants under nitrogen limited conditions. Nod factors initiate the establishment of a symbiotic relationship between legumes and rhizobia by inducing nodulation. Nod factors produce the differentiation of plant tissue in root hairs into nodules where the bacteria reside and are able to fix nitrogen from the atmosphere for the plant in exchange for photosynthates and the appropriate environment for nitrogen fixation. One of the most important features provided by the plant in this symbiosis is the production of leghemoglobin, which maintains the oxygen concentration low and prevents the inhibition of nitrogenase activity. Chemical Structure Nod factors structurally are lipochitooligosaccharides (LCOs) that consist of an ''N''-acetyl-D-glucosamine chain linked through β-1,4 linkage with a fatty acid of variable identity attached ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonelline
Trigonelline is an alkaloid with chemical formula . It is a zwitterion formed by the methylation of the nitrogen atom of niacin (vitamin B3). Trigonelline is a product of niacin metabolism that is excreted in urine of mammals. Trigonelline occurs in many plants. It has been isolated from the Japanese radish (''Raphanus sativus'' cv. Sakurajima Daikon), fenugreek seeds (''Trigonella foenum-graecum'', hence the name), garden peas, hemp seed, oats, potatoes, ''Stachys'' species, dahlia, ''Strophanthus'' species, and ''Dichapetalum cymosum''. Trigonelline is also found in coffee. Higher levels of trigonelline is found in arabica coffee. Holtz, Kutscher, and Theilmann have recorded its presence in a number of animals. Chemistry Trigonelline crystallizes as a monohydrate from alcohol in hygroscopic prisms (m.p. 130 °C or 218 °C 'dry, dec.''. It is readily soluble in water or warm alcohol, less so in cold alcohol, and slightly so in chloroform or ether. The salts c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medicarpin
Medicarpin is a pterocarpan, a derivative of isoflavonoids. Natural occurrences Medicarpin is found in ''Medicago truncatula'' and '' Swartzia madagascariensis''. It can also be found in ''Maackia amurensis'' cell cultures. The root nodule formation by '' Sinorhizobium meliloti'' is apparently dependent on the flavonoids pathway. Metabolism Pterocarpin synthase has 3 substrates : medicarpin, NADP+ and H2O, and 3 products : vestitone, NADPH Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NADP ... and H+. References Pterocarpans {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luteolin
Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance. Luteolin is the principal yellow dye compound that is obtained from the plant ''Reseda luteola'', which has been used as a source of the dye since at least the first millennium B.C. Luteolin was first isolated in pure form, and named, in 1829 by the French chemist Michel Eugène Chevreul. The luteolin empirical formula was determined by the Austrian chemists Heinrich Hlasiwetz and Leopold Pfaundler in 1864. In 1896, the English chemist Arthur George Perkin proposed the correct structure for luteolin. Perkin's proposed structure for luteolin was confirmed in 1900 when the Polish-Swiss chemist Stanislaw Kostanecki (1860–1910) and his students A. Różycki and J. Tambor synthesized luteolin. Natural occurrences Luteolin is most often found in leaves, but it is also seen in rinds, barks, clover blossom, and ragweed pollen. It has also been isolated from the aromatic flowering plant, ''Salvia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquiritigenin
Liquiritigenin is a flavanone that was isolated from ''Glycyrrhiza uralensis'', and is found in a variety of plants, including ''Glycyrrhiza glabra'' (licorice). It is an estrogenic compound which acts as a selective agonist of the ERβ subtype of the estrogen receptor (ER), though it is also reported to act as an ERα partial agonist at sufficient concentrations. It also has a choleretic effect. Liquiritigenin,NADPH:oxygen oxidoreductase (hydroxylating, aryl migration) is an enzyme that uses liquiritigenin, O2, NADPH and H+ to produce 2,7,4'-trihydroxyisoflavanone, H2O, and NADP+. See also * Menerba * Prinaberel (ERB-041) * Diarylpropionitrile (DPN) * WAY-200070 * PHTPP * (R,R)-Tetrahydrochrysene ((R,R)-THC) * Propylpyrazoletriol (PPT) * Methylpiperidinopyrazole Methylpiperidinopyrazole (MPP) is a synthetic, nonsteroidal, and highly selective antagonist of ERα that is used in scientific research to study the function of this receptor. It has 200-fold selectivity for ER ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4′,7-dihydroxyflavone
4′,7-Dihydroxyflavone is a flavone. It is found in ''Medicago truncatula'' in relation with the root nodulation symbiont ''Sinorhizobium meliloti'' or in seeds of '' Sophora viciifolia''. Like many other flavonoids, 4′,7-dihydroxyflavone has been found to possess activity at opioid receptors ''in vitro''. Specifically, it acts as an antagonist of the μ-opioid receptor and, with lower affinity, of the κ- and δ-opioid receptor The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein coupled receptor coupled to the G protein Gi/G0 and has enkephalins as its endogenous lig ...s. See also * Pratol (7-hydroxy-4′-methoxyflavone) is the ''O''-methylated form of the molecule. References Flavones Kappa-opioid receptor antagonists Mu-opioid receptor antagonists {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
