|
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 (bioreacto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Tissue Culture
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method known as micropropagation. Different techniques in plant tissue culture may offer certain advantages over traditional methods of propagation, including: * The production of exact copies of plants that produce particularly good flowers, fruits, or have other desirable traits. * To quickly produce mature plants. * The production of multiples of plants in the absence of seeds or necessary pollinators to produce seeds. * The regeneration of whole plants from plant cells that have been genetically modified. * The production of plants in sterile containers that allows them to be moved with greatly reduced chances of transmitting diseases, pests, and pathogens. * The production of plants from seeds that otherwise have very low chances of germinating an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolites
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. Specific secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory and other interspecies defenses. Humans use secondary metabolites as medicines, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, a 1910 Nobel Prize laureate for medicine and physiology in 1910. 30 years later a Polish botanist Friedrich Czapek described secondary met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome. An organism that is generated through genetic engineering is considered to be genetically modified (GM) an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agrobacterium Rhizogenes
''Rhizobium rhizogenes'' (formerly ''Agrobacterium rhizogenes'') is a Gram-negative soil bacterium that produces hairy root disease in dicotyledonous plants. ''R. rhizogenes'' induces the formation of proliferative multiple-branched adventitious roots at the site of infection, so-called 'hairy roots'. In the rhizosphere, plants may suffer from wounds by soil pathogens or other sources. This leads to the secretion of phenolic compounds like acetosyringone which have chemotactic effects that attract the bacteria. Under such conditions, certain bacterial genes are turned on leading to the transfer of its T-DNA from its root-inducing plasmid (Ri plasmid) into the plant through the wound. After integration and expression, ''in vitro'' or under natural conditions, the hairy root phenotype is observed, which typically includes overdevelopment of a root system that is not completely geotropic, and altered (wrinkled) leaf morphology, if leaves are present. Bacterial genes may be retaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water. Function The major functions of roots are absorption of water, plant nutrition and anchoring of the plant body to the ground. Anatomy Root morphology is divided into four zones: the root cap, the apical meristem, the elongation zone, and the hair. The root cap of new roots helps the root penetrate the soil. These root caps are sloughed off as the root goes deeper creating a slimy surface that provides lubrication. The apical meristem behind the root cap produces new root cells that elongate. Then, root hairs form that absorb water and mineral nutrients from the soil. The first root in seed producing plants is the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioreactors
A bioreactor refers to any manufactured device or system that supports a biologically active environment. In one case, a bioreactor is a vessel in which a chemical reaction, chemical process is carried out which involves organisms or biochemistry, biochemically active chemical substance, substances derived from such organisms. This process can either be Aerobic organism, aerobic or Anaerobic organism, anaerobic. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a device or system designed to grow Cell (biology), cells or Biological tissue, tissues in the context of cell culture. These devices are being developed for use in tissue engineering or biochemical engineering, biochemical/bioprocess engineering, bioprocess engineering. On the basis of mode of operation, a bioreactor may be classified as batch reactor, batch, fed-batch, fed batch or continuous reactor, continuous (e.g. a conti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoremediation
Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronomic techniques to either contain, remove or render toxic environmental contaminants harmless". The term is an amalgam of the Greek ''phyto'' (plant) and Latin ''remedium'' (restoring balance). Although attractive for its cost, phytoremediation has not been demonstrated to redress any significant environmental challenge to the extent that contaminated space has been reclaimed. Phytoremediation is proposed as a cost-effective plant-based approach of environmental remediation that takes advantage of the ability of plants to concentrate elements and compounds from the environment and to detoxify various compounds. The concentrating effect results from the ability of certain plants called hyperaccumulators to bioaccumulate chemicals. The remediat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome. An organism that is generated through genetic engineering is considered to be genetically modified (GM) an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transfer DNA
The transfer DNA (abbreviated T-DNA) is the transferred DNA of the tumor-inducing (Ti) plasmid of some species of bacteria such as ''Agrobacterium tumefaciens'' and ''Agrobacterium rhizogenes(actually an Ri plasmid)''. The T-DNA is transferred from bacterium into the host plant's nuclear DNA genome. The capability of this specialized tumor-inducing (Ti) plasmid is attributed to two essential regions required for DNA transfer to the host cell. The T-DNA is bordered by 25-base-pair repeats on each end. Transfer is initiated at the right border and terminated at the left border and requires the ''vir'' genes of the Ti plasmid. The bacterial T-DNA is about 24,000 base pairs long and contains plant-expressed genes that code for enzymes synthesizing opines and phytohormones. By transferring the T-DNA into the plant genome, the bacterium essentially reprograms the plant cells to grow into a tumor and produce a unique food source for the bacteria. The synthesis of the plant hormones auxin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Embryogenesis
Plant embryonic development, also plant embryogenesis is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination. The zygote produced after fertilization must undergo various cellular divisions and differentiations to become a mature embryo. An end stage embryo has five major components including the shoot apical meristem, hypocotyl, root meristem, root cap, and cotyledons. Unlike the embryonic development in animals, and specifically in humans, plant embryonic development results in an immature form of the plant, lacking most structures like leaves, stems, and reproductive structures. However, both plants and animals including humans, pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification. Morphogenic events Embryogenesis occurs naturally as a result of sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
