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Opines
Opines are low molecular weight compounds found in plant crown gall tumors or hairy root tumors produced by pathogenic bacteria of the genus ''Agrobacterium'' and ''Rhizobium''. Opine biosynthesis is catalyzed by specific enzymes encoded by genes contained in a small segment of DNA (known as the T-DNA, for 'transfer DNA'), which is part of the Ti plasmid (in ''Agrobacterium'') or Ri plasmid (in ''Rhizobium''), inserted by the bacterium into the plant genome. The opines are used by the bacterium as an important energy, carbon and nitrogen source. Each strain of ''Agrobacterium'' and ''Rhizobium'' induces and catabolizes a specific set of opines, this set typifying the Ti plasmid and Ri plasmid. There are some 30 different opines described so far. Chemical structure Chemically, opines fall into two major structural classes: 1. The vast majority are secondary amine derivatives resulting from the reduction of the imine formed by condensation of an amino acid, either with a ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ti Plasmid
A tumour inducing (Ti) plasmid is a plasmid found in pathogenic species of ''Agrobacterium'', including Agrobacterium tumefaciens, ''A. tumefaciens'', Rhizobium rhizogenes, ''A. rhizogenes'', ''A. rubi'' and Allorhizobium vitis, ''A. vitis''. Evolutionarily, the Ti plasmid is part of a family of plasmids carried by many species of Alphaproteobacteria. Members of this plasmid family are defined by the presence of a conserved DNA region known as the ''repABC'' gene cassette, which mediates the DNA replication, replication of the plasmid, the partitioning of the plasmid into daughter cells during cell division as well as the maintenance of the plasmid at low copy numbers in a cell. The Ti plasmids themselves are sorted into different categories based on the type of molecule, or opine, they allow the bacteria to break down as an energy source. The presence of this Ti plasmid is essential for the bacteria to cause crown gall disease in plants. This is facilitated via certain crucial r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nopaline
Nopaline is a chemical compound derived from the amino acids glutamic acid and arginine. It is classified as an opine. Ti plasmids are classified on the basis of the different types of opines they produce. These may be nopaline plasmids, octopine plasmids and agropine plasmids. These opines are condensation products of amino acids and keto acids or may be derived from sugars. The opines are used as carbon and nitrogen sources and metabolized by ''Agrobacterium ''Agrobacterium'' is a genus of Gram-negative bacteria established by Harold J. Conn, H. J. Conn that uses horizontal gene transfer to cause tumors in plants. ''Agrobacterium tumefaciens'' is the most commonly studied species in this genus. ''Agr ...''. References Alpha-Amino acids Amino acid derivatives {{OrganicAcid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Gall
''Agrobacterium'' is a genus of Gram-negative bacteria established by H. J. Conn that uses horizontal gene transfer to cause tumors in plants. ''Agrobacterium tumefaciens'' is the most commonly studied species in this genus. ''Agrobacterium'' is well known for its ability to transfer DNA between itself and plants, and for this reason it has become an important tool for genetic engineering. Nomenclatural history Leading up to the 1990s, the genus ''Agrobacterium'' was used as a wastebasket taxon. With the advent of 16S sequencing, many ''Agrobacterium'' species (especially the marine species) were reassigned to genera such as ''Ahrensia'', ''Pseudorhodobacter'', ''Ruegeria'', and ''Stappia''. The remaining ''Agrobacterium'' species were assigned to three biovars: biovar 1 (''Agrobacterium tumefaciens''), biovar 2 (''Agrobacterium rhizogenes''), and biovar 3 (''Agrobacterium vitis''). In the early 2000s, ''Agrobacterium'' was synonymized with the genus ''Rhizobium''. This move pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopine Structure
Octopine is a derivative (chemistry), derivative of the amino acids arginine and alanine. It was the first member of the class of chemical compounds known as opines to be discovered. Octopine gets its name from ''Octopus octopodia'' from which it was first isolated in 1927. Octopine has been isolated from the muscle tissue of invertebrates such as octopus, ''Pecten maximus'' and ''Sipunculus nudus'' where it functions as an analog of lactic acid. Plants may also produce this compound after crown gall, infection by ''Agrobacterium, Agrobacterium tumefaciens'' and transfer of the octopine synthesis gene from the bacterium to the plant. Octopine is formed by reductive condensation reaction, condensation of pyruvic acid and arginine through the action of the Nicotinamide adenine dinucleotide, NADH-dependent enzyme D-octopine dehydrogenase, octopine dehydrogenase (ODH). The reaction is reversible so that pyruvic acid and arginine can be regenerated. : References {{reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agrobacterium
''Agrobacterium'' is a genus of Gram-negative bacteria established by Harold J. Conn, H. J. Conn that uses horizontal gene transfer to cause tumors in plants. ''Agrobacterium tumefaciens'' is the most commonly studied species in this genus. ''Agrobacterium'' is well known for its ability to transfer DNA between itself and plants, and for this reason it has become an important tool for genetic engineering. Nomenclatural history Leading up to the 1990s, the genus ''Agrobacterium'' was used as a wastebasket taxon. With the advent of 16S ribosomal RNA, 16S sequencing, many ''Agrobacterium'' species (especially the marine species) were reassigned to genera such as ''Ahrensia'', ''Pseudorhodobacter'', ''Ruegeria'', and ''Stappia''. The remaining ''Agrobacterium'' species were assigned to three biovars: biovar 1 (''Agrobacterium tumefaciens''), biovar 2 (''Agrobacterium rhizogenes''), and biovar 3 (''Agrobacterium vitis''). In the early 2000s, ''Agrobacterium'' was synonymized with the g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopine
Octopine is a derivative of the amino acids arginine and alanine. It was the first member of the class of chemical compounds known as opines to be discovered. Octopine gets its name from '' Octopus octopodia'' from which it was first isolated in 1927. Octopine has been isolated from the muscle tissue of invertebrates such as octopus, '' Pecten maximus'' and '' Sipunculus nudus'' where it functions as an analog of lactic acid. Plants may also produce this compound after infection by '' Agrobacterium tumefaciens'' and transfer of the octopine synthesis gene from the bacterium to the plant. Octopine is formed by reductive condensation of pyruvic acid Pyruvic acid (CH3COCOOH) is the simplest of the keto acids, alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate acid, conjugate base, CH3COCOO−, is an metabolic intermediate, intermediate in several m ... and arginine through the action of the NADH-dependent enzyme octopine de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ri Plasmid
The root inducing (Ri) -plasmid of ''Rhizobium rhizogenes'' (formerly ''Agrobacterium rhizogenes'') is a plasmid capable of undergoing horizontal gene transfer of its transfer DNA (T-DNA), upon contact with a plant host. The T-DNA of the Ri-plasmid affects the plant host in such a way, that gene expression is altered, especially in regard to phytohormonal balances, metabolism and certain phenotypical characteristics. The Ri-plasmid is generally classified based on the type of opines produced, and four have been described so far: the agropine, cucumopine, mannopine, and mikinopine types. While all types of Ri-plasmid contain T-DNA, the agropine plasmid contains both a TL and a TR-domain (left and right, resp.). The TL-DNA is reminiscent of the T-DNA of the other strain types, containing a virulence region with a set of virulence (''vir'') genes, opine synthesis genes, root oncogenic loci (''rol'') genes (''rolA'', ''rolB'', ''rolC'' and ''rolD'') and a number of other genes with u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hairy Root Culture
Hairy root culture, also called transformed root culture, is a type of plant tissue culture that is used to study plant metabolic processes or to produce valuable secondary metabolites or recombinant proteins, often with plant genetic engineering. A naturally occurring soil bacterium ''Agrobacterium rhizogenes'' that contains root-inducing plasmids (also called Ri plasmids) can infect plant roots and cause them to produce a food source for the bacterium, opines, and to grow abnormally. The abnormal roots are particularly easy to culture in artificial media because hormones are not needed in contrast to adventitious roots, and they are neoplastic, with indefinite growth. The neoplastic roots produced by ''A. rhizogenes'' infection have a high growth rate (compared to untransformed adventitious roots), as well as genetic and biochemical stability. Currently the main constraint for commercial utilization of hairy root culture is the development and up-scaling of appropriate (biorea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined from either sugarcane or sugar beet. Sugar mills – typically located in tropical regions near where sugarcane is grown – crush the cane and produce raw sugar which is shipped to other factories for refining into pure sucrose. Sugar beet factories are located in temperate climates where the beet is grown, and process the beets directly into refined sugar. The Sugar refinery, sugar-refining process involves washing the raw sugar crystals before dissolving them into a sugar syrup which is filtered and then passed over carbon to remove any residual colour. The sugar syrup is then concentrated by boiling under a vacuum and crystallized as the final purification process to produce crystals of pure sucrose that are clear, odorless, and sweet. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabinose
Arabinose is an aldopentose – a monosaccharide containing five carbon atoms, and including an aldehyde (CHO) functional group. Properties For biosynthetic reasons, most saccharides are almost always more abundant in nature as the "D"-form, or structurally analogous to D-glyceraldehyde.The D/L nomenclature does not refer to the molecule's optical rotation properties but to its structural analogy to glyceraldehyde. However, L-arabinose is in fact more common than D-arabinose in nature and is found in nature as a component of biopolymers such as hemicellulose and pectin. The L-arabinose operon, also known as the araBAD operon, has been the subject of much biomolecular research. The operon directs the catabolism of arabinose in ''E. coli'', and it is dynamically activated in the presence of arabinose and the absence of glucose. A classic method for the organic synthesis of arabinose from glucose is the Wohl degradation. : Etymology Arabinose gets its name from gum arabic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopus
An octopus (: octopuses or octopodes) is a soft-bodied, eight-limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the centre point of the eight limbs. An octopus can radically deform its shape, enabling it to squeeze through small gaps. They trail their appendages behind them as they swim. The siphon is used for respiration and locomotion (by water jet propulsion). Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse invertebrates. Octopuses inhabit various ocean habitats, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature early, and are short-lived. In most species, the male uses a speciall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first edition in 1884, traces the historical development of the English language, providing a comprehensive resource to scholars and academic researchers, and provides ongoing descriptions of English language usage in its variations around the world. In 1857, work first began on the dictionary, though the first edition was not published until 1884. It began to be published in unbound Serial (literature), fascicles as work continued on the project, under the name of ''A New English Dictionary on Historical Principles; Founded Mainly on the Materials Collected by The Philological Society''. In 1895, the title ''The Oxford English Dictionary'' was first used unofficially on the covers of the series, and in 1928 the full dictionary was republished in 10 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
