Brassinosteroid
Brassinosteroids (BRs or less commonly BS) are a class of polyhydroxysteroids that have been recognized as a sixth class of plant hormones and may have utility as anticancer drugs for treating endocrine-responsive cancers by inducing apoptosis of cancer cells and inhibiting cancerous growth. These brassinosteroids were first explored during the 1970s when Mitchell et al. reported promotion in stem elongation and cell division by the treatment of organic extracts of rapeseed (''Brassica napus'') pollen. Brassinolide was the first brassinosteroid to be isolated in 1979, when pollen from ''Brassica napus'' was shown to promote stem elongation and cell divisions, and the biologically active molecule was isolated. The yield of brassinosteroids from 230 kg of ''Brassica napus'' pollen was only 10 mg. Since their discovery, over 70 BR compounds have been isolated from plants. Biosynthesis The BR is biosynthesised from campesterol. The biosynthetic pathway was elucidated ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Brassinosteroid Insensitive-1
Brassinosteroid insensitive 1 (BRI1) is the major receptor of the plant hormone brassinosteroid. It plays very important roles in plant development, especially in the control of cell elongation and for the tolerance of environmental stresses. BRI1 enhances cell elongation, promotes pollen development, controls vasculature development and promotes chilling and freezing tolerance. BRI1 is one of the most well studied hormone receptors and it acts a model for the study of membrane-bound receptors in plants. Structure BRI1 is an integral membrane protein. On the extracellular side of the membrane lies a series of 25 leucine-rich repeats (LRRs). The LRR domain forms a horseshoe shape. An atypical LRR within this domain acts as the brassinosteroid binding site. Next to the LRR domain there is a single-pass transmembrane section. The intracellular domain of BRI1 functions as a kinase and it is this domain triggers the phosphorylation cascade that results in changes of gene expression. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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BRI1 Kinase Inhibitor 1
Brassinosteroid insensitive 1 (BRI1) is the major Receptor (biochemistry), receptor of the plant hormone brassinosteroid. It plays very important roles in plant development, especially in the control of Plant cell, cell elongation and for the tolerance of Abiotic stress, environmental stresses. BRI1 enhances cell elongation, promotes pollen development, controls Plant vasculature, vasculature development and promotes chilling and freezing tolerance. BRI1 is one of the most well studied hormone receptors and it acts a model for the study of membrane-bound receptors in plants. Structure BRI1 is an integral membrane protein. On the extracellular side of the Cell membrane, membrane lies a series of 25 leucine-rich repeats (LRRs). The LRR Protein domain, domain forms a horseshoe shape. An atypical LRR within this domain acts as the brassinosteroid binding site. Next to the LRR domain there is a single-pass Transmembrane protein, transmembrane section. The intracellular domain of BRI1 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Plant Hormones
Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of Organ (anatomy), organ size, pathogen defense, Stress (biology), stress tolerance and Reproduction, reproductive development. Unlike in animals (in which hormone production is restricted to specialized glands) each plant cell is capable of producing hormones. Frits Warmolt Went, Went and Thimann coined the term "phytohormone" and used it in the title of their 1937 book. Phytohormones occur across the plant kingdom, and even in algae, where they have similar functions to those seen in vascular plant, vascular plants ("higher plants"). Some phytohormones also occur in microorganisms, such as unicellular fungus, fungi and bacteria, however in these cases they do not play a hormonal role and can better be regarded as secondary metabolites. Characteristi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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BRI1-associated Receptor Kinase 1
BRI1-associated receptor kinase 1 (BAK1- also known as somatic embryogenesis receptor kinase 3 or SERK3) is an important plant protein that has diverse functions in plant development. Structure BAK1 belongs to a large group of plant proteins known as the Leucine-rich repeat receptor kinases (LRR-RKs). In the model plant species ''Arabidopsis thaliana'', BAK1 and 4 other closely related proteins form a sub-group within the LRR-RK family, known as the somatic embryogenesis receptor kinases (SERKs). All 5 SERKs are transmembrane proteins. They consist of an extracellular domain, a single transmembrane pass and an intracellular domain. The extracellular domain is composed of several leucine rich repeats, and the intracellular domain functions as a protein kinase. BAK1 is thought to interact with many other LRR-RKs and the signalling output of BAK1 is dependent on its binding partner Roles in plant development Brassinosteroid signalling BAK1 was initially identified for it ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Brassinolide2
Brassinolide is a plant hormone. The first isolated brassinosteroid, it was discovered when it was shown that pollen from rapeseed (''Brassica napus'') could promote stem elongation and cell division. The biologically active component was isolated and named brassinolide. Biosynthesis The production of brassinolide begins with a closely related sterol called campesterol, which is found in the cell membrane. Initially, it is reduced by an enzyme called DET2. This is followed by a series of oxidation reactions, facilitated by cytochrome P-450 enzymes, which add hydroxyl groups to the molecule. The most biologically significant of these reactions is the C6 oxidation, where a ketone is formed at the C6 carbon position. This single reaction increases the biological activity of the molecule by a factor of 200. Depending on when this C6 oxidation occurs, it is referred to as either the early or late C6 oxidation pathway. Both of these synthetic pathways have been observed in Arabidopsi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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24-Epibrassinolide
24-Epibrassinolide is a type of brassinosteroid, a natural occurring plant hormone Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of Organ (anat .... It was first discovered 1979 as a growth promoting substance in rape pollen, and was subsequently discovered in many other plant organs. 24-Epibrassinolide is essential for proper plant development growth and development, is involved in the regulation of cell elongation and division, and has been shown to improve plant functions in salt- and nickel-stressed environments, as well as increasing enzyme activity. It is sold commercially as a white powder for use in plant culture. References {{DEFAULTSORT:Epibrassinolide, 24- Plant hormones ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Homology (biology)
In biology, homology is similarity in anatomical structures or genes between organisms of different taxa due to shared ancestry, ''regardless'' of current functional differences. Evolutionary biology explains homologous structures as retained heredity from a common descent, common ancestor after having been subjected to adaptation (biology), adaptive modifications for different purposes as the result of natural selection. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this from Aristotle's biology onwards, and it was explicitly analysed by Pierre Belon in 1555. A common example of homologous structures is the forelimbs of vertebrates, where the bat wing development, wings of bats and origin of avian flight, birds, the arms of primates, the front flipper (anatomy), flippers of whales, and the forelegs of quadrupedalis ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Allium Cepa
An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion which was classified as a separate species until 2011. The onion's close relatives include garlic, scallion, leek, and chives. The genus contains several other species variously called onions and cultivated for food, such as the Japanese bunching onion ''Allium fistulosum'', the tree onion ''Allium'' × ''proliferum'', and the Canada onion ''Allium canadense''. The name '' wild onion'' is applied to a number of ''Allium'' species, but ''A. cepa'' is exclusively known from cultivation. Its ancestral wild original form is not known, although escapes from cultivation have become established in some regions. The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season. The onion ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Transcription Factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are Gene expression, expressed in the desired Cell (biology), cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are approximately 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |