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Inducible Plant Defenses Against Herbivory
Plants have evolution, evolved many defense mechanisms against insect herbivory in the 350 million years in which they have co-evolution, co-evolved. Such defenses can be broadly classified into two categories: (1) permanent, constitutive defenses, and (2) temporary, inducible defenses.Karban R, Baldwin IT. Induced responses to herbivory. Chicago: Chicago University Press; 1997. These differ in that constitutive defenses are present before an herbivore attacks, while induced defenses are activated only when attacks occur. In addition to constitutive defenses, initiation of specific defense responses to herbivory is an important strategy for plant persistence and survival. Benefits of induced defences Inducible defenses allow plants to be phenotypic plasticity, phenotypically plastic. This may confer an advantage over constitutive defenses for multiple reasons. First, it may reduce the chance that attacking insects adapt to plant defenses.Karban R, Agrawal AA, Mangel M. The benef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation. The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book ''On the Origin of Species''. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) phenotypic variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, modified leaves; corolla, the petals; androecium, the male reproductive unit consisting of stamens and pollen; and gynoecium, the female part, containing style and stigma, which receives the pollen at the tip of the style, and ovary, which contains the ovules. When flowers are arranged in groups, they are known collectively as inflorescences. Floral growth originates at stem tips and is controlled by MADS-box genes. In most plant species flowers are heterosporous, and so can produce sex cells of both sexes. Pollination mediates the transport of pollen to the ovules in the ovaries, to facilitate sexual reproduction. It can occur between different plants, as in cross-pollination, or between flowers on the same plant or even the same f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivory
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat non-vascular autotrophs such as mosses, algae and lichens, but do not include those feeding on decomposed plant matters (i.e. detritivores) or macrofungi (i.e. fungivores). As a result of their plant-based diet, herbivorous animals typically have mouth structures ( jaws or mouthparts) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase) to digest polysaccharides. Grazing herbivores such as horses and cattles have wide flat- crowned teeth that are better adapted for grinding grass, tree bark and other tougher lignin-containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A large perce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Tolerance To Herbivory
Tolerance is the ability of plants to mitigate the negative fitness effects caused by herbivory. It is one of the general plant defense strategies against herbivores, the other being resistance, which is the ability of plants to prevent damage (Strauss and Agrawal 1999). Plant defense strategies play important roles in the survival of plants as they are fed upon by many different types of herbivores, especially insects, which may impose negative fitness effects (Strauss and Zangerl 2002). Damage can occur in almost any part of the plants, including the roots, stems, leaves, flowers and seeds (Strauss and Zergerl 2002). In response to herbivory, plants have evolved a wide variety of defense mechanisms and although relatively less studied than resistance strategies, tolerance traits play a major role in plant defense (Strauss and Zergerl 2002, Rosenthal and Kotanen 1995). Traits that confer tolerance are controlled genetically and therefore are heritable traits under selection (Stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Defense Against Herbivory
Plant defense against herbivory or host-plant resistance is a range of adaptations Evolution, evolved by plants which improve their fitness (biology), survival and reproduction by reducing the impact of herbivores. Many plants produce secondary metabolites, known as Heterotelergones, allelochemicals, that influence the behavior, growth, or survival of herbivores. These chemical defenses can act as repellents or toxins to herbivores or reduce plant digestibility. Another defensive strategy of plants is changing their attractiveness. Plant perception (physiology), Plants can sense being touched, and they can respond with strategies to defend against herbivores. Plants alter their appearance by changing their size or quality in a way that prevents overconsumption by large herbivores, reducing the rate at which they are consumed. Other defensive strategies used by plants include escaping or avoiding herbivores at any time in any placefor example, by growing in a location where plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxidase
Peroxidases or peroxide reductases ( EC numberbr>1.11.1.x are a large group of enzymes which play a role in various biological processes. They are named after the fact that they commonly break up peroxides, and should not be confused with other enzymes that ''produce'' peroxide, which are often oxidases. Functionality Peroxidases typically catalyze a reaction of the form: :ROOR' + \overset + 2H+ -> ce + R'OH Optimal substrates For many of these enzymes the optimal substrate is hydrogen peroxide, but others are more active with organic hydroperoxides such as lipid peroxides. Peroxidases can contain a heme cofactor in their active sites, or alternately redox-active cysteine or selenocysteine residues. The nature of the electron donor is very dependent on the structure of the enzyme. * For example, horseradish peroxidase can use a variety of organic compounds as electron donors and acceptors. Horseradish peroxidase has an accessible active site, and many compounds can re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrophysa Viridula
''Gastrophysa viridula'', known as the green dock beetle (note: the similar '' Gastrophysa cyanea'' in North America is also called the green dock beetle), green dock leaf beetle or green sorrel beetle, is a species of beetle native to Europe. Description The length of the green dock beetle varies between sexes, with the males being 4 mm and the females being 7 mm. During the mating season, females have enlarged abdomens. Both sexes are green with a metallic shimmer, which, depending on the light, can be gold green, blue, purple, violet, or red. The legs of this species also shimmer a metallic green, and are strongly built. The antennae are serrated and are medium in length. Subspecies *''Gastrophysa viridula pennina'' ( Weise, 1882) *''Gastrophysa viridula viridula'' (De Geer, 1775) Distribution and habitat The green dock beetle is commonly found in central Europe, also common and widespread in Britain. Its range extends eastward into western Siberia and the Caucasus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rumex Obtusifolius
''Rumex obtusifolius'', commonly known as bitter dock, broad-leaved dock, bluntleaf dock, dock leaf, dockens or butter dock, is a perennial plant in the family Polygonaceae. It is native to Europe, but is found on all temperate continents. It is a highly invasive species in some zones, resulting from its abundant seed dispersal, adaptability to reproduce, aggressive roots, ability to tolerate extreme climates, and hardiness. Etymology The name, ''Rumex obtusifolius'', was assigned by Carl Linnaeus in the 18th century, and has remained unchanged, although there are numerous subspecies. ''Rumex'' was Pliny's name for sorrel,Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 277, 335 while ''obtusifolius'' means 'obtuse-leaved' (obtuse + foliage). Description ''Rumex obtusifolius'' is a perennial herbaceous flowering plant that grows to a height of . It is easily recognizable by its very large oval leaves with cordate bases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotiana Tabacum
''Nicotiana tabacum'', or cultivated tobacco, is an annually grown herbaceous plant of the genus ''Nicotiana''. ''N. tabacum'' is the most commonly grown species in the genus ''Nicotiana,'' as the plant's leaves are commercially harvested to be processed into tobacco for human use. The plant is tropical in origin, is commonly grown throughout the world, and is often found in cultivation. It grows to heights between . Research is ongoing into its ancestry among wild ''Nicotiana'' species, but it is believed to be a hybrid of '' Nicotiana sylvestris'', '' N. tomentosiformis'', and possibly '' N. otophora''. Description It is an annual plant that grows high and is sticky haired on all parts. The stems are thick and not very branched. The leaves can be over long with the blades ovate to elliptical, or obovate, pointed towards the front and, at the base, run down the stem or are sessile, encompassing the stem. The scented inflorescences are multi-branched panicles. The flower s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-evolution
In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well as gene-culture coevolution. Charles Darwin mentioned evolutionary interactions between flowering plants and insects in ''On the Origin of Species'' (1859). Although he did not use the word coevolution, he suggested how plants and insects could evolve through reciprocal evolutionary changes. Naturalists in the late 1800s studied other examples of how interactions among species could result in reciprocal evolutionary change. Beginning in the 1940s, plant pathologists developed breeding programs that were examples of human-induced coevolution. Development of new crop plant varieties that were resistant to some diseases favored rapid evolution in pathogen populations to overcome those plant defenses. That, in turn, required the development of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotine
Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve drug withdrawal, withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits (nAChRα9 and nAChRα10) where it acts as a receptor antagonist. Nicotine constitutes approximately 0.6–3.0% of the dry weight of tobacco. Nicotine is also present at Parts-per notation, ppb concentrations in edible plants in the family Solanaceae, including potatoes, tomatoes, and eggplants, though sources disagree on whether this has any biological significance to human consumers. It functions as an plant defense against herbivory, antiherbivore toxin; consequently, nicotine was widely used as an insecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucosinolates
Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. These natural chemicals most likely contribute to plant defence against pests and diseases, and impart a characteristic bitter flavor property to cruciferous vegetables. Occurrence Glucosinolates occur as secondary metabolites of almost all plants of the order Brassicales. This includes the economically important family Brassicaceae as well as Capparaceae and Caricaceae. Outside of the Brassicales, the genera '' Drypetes'' and '' Putranjiva'' in the family Putranjivaceae, are the only other known occurrence of glucosinolates. Glucosinolates occur in various edible plants such as cabbage (white cabbage, Chinese cabbage, broccoli), Brussels sprouts, watercress, arugula, horseradish, capers, and radishes where the breakdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
