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Effector-triggered Resistance
Plant disease resistance protects plants from pathogens in two ways: by pre-formed structures and chemicals, and by infection-induced responses of the immune system. Relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant (and hence a reduction of disease), while the term Tolerance to infections, disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels. Disease outcome is determined by the three-way interaction of the pathogen, the plant, and the environmental conditions (an interaction known as the disease triangle). Defense-activating compounds can move cell-to-cell and systematically through the plant's vascular system. However, plants do not have circulating Immune system, immune cells, so most cell types exhibit a broad suite of Antimicrobial peptides, antimicrobial defenses. Although obvious ''qualitative'' differences in disease resistance can be observed when multiple specim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chestnut Blight
The pathogenic fungus ''Cryphonectria parasitica'' (formerly ''Endothia parasitica'') is a member of the Ascomycota (sac fungi). This necrotrophic fungus is native to East Asia and South East Asia and was introduced into Europe and North America in the early 1900s. Strains of the fungus spread more or less rapidly and caused significant tree loss in both regions. Strains of the fungus can be more or less virulent. Overview ''Cryphonectria parasitica'' is a parasitic fungus of chestnut trees. This disease came to be known as chestnut blight. Naturally found in South East Asia, accidental introductions led to invasive populations of ''C. parasitica'' in North America and Europe. In the first half of the 20th century, the fungal disease had a devastating economic and social impact on communities in the eastern United States. It killed an estimated four billion trees; or, by another count, 3.5 billion trees through 2013. Less severe impacts have occurred in Europe due to widespread ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheat Yellow Rust
Wheat yellow rust (''Puccinia striiformis'' f.sp. ''tritici''), also known as wheat stripe rust, is one of the three major wheat Rust (fungus), rust diseases, along with Stem rust, stem rust of wheat (''Puccinia graminis'' f.sp. tritici) and Leaf rust (barley), leaf rust (''Puccinia triticina'' f.sp. tritici). History As R.P. Singh, J. Huerta-Espino, and A.P. Roelfs say in their 2002 comprehensive review of literature on the wheat rusts for UN FAO: Although Gadd first described stripe rust of wheat in 1777, it was not until 1896 that Eriksson and Henning (1896) showed that stripe rust resulted from a separate pathogen, which they named ''P. glumarum''. In 1953, Hylander et al. (1953) revived the name ''P. striiformis''. A stripe rust outbreak in northwest Syria contributed to the beginning of the Syrian civil war, Syrian Civil War by increasing food prices. Life cycle Other cereal rust fungi have macrocyclic, heteroecious life cycles, involving five spore stages and two Phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. Chemical substances can exist in several different physical states or phases (e.g. solids, liquids, gases, or plasma) without changing their chemical composition. Substances transition between these phases of matter in response to changes in temperature or pressure. Some chemical substances can be combined or converted into new substances by means of chemical reactions. Chemicals that do not possess this ability are said to be inert. Pure water is an example of a chemical substance, with a constant composition of two hydrogen atoms bonded to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Antimicrobial medicines to treat infection are known as antimicrobial chemotherapy, while antimicrobial drugs are used to prevent infection, which known as antibiotic prophylaxis, antimicrobial prophylaxis. The main classes of antimicrobial agents are disinfectants (non-selective agents, such as bleach), which kill a wide range of microbes on surfaces to prevent the spread of illness, antiseptics which are applied to living tissue and help reduce infection during surgery, and antibiotics which destroy microorganisms within the body. The term ''antibiotic'' originally described only those formulations derived from living microorga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most Prokaryote, prokaryotes, with the exception of Mollicutes, mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In Embryophyte, land plants, the primary cell wall comprises Polysaccharide, polysaccharides like cellulose, hemicelluloses, and pectin. Often, other Polymer, polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Cuticle
A plant cuticle is a protecting film covering the outermost skin layer (epidermis) of leaves, young shoots and other aerial plant organs (aerial here meaning all plant parts not embedded in soil or other substrate) that have no '' periderm''. The film consists of lipid and hydrocarbon polymers infused with wax, and is synthesized exclusively by the epidermal cells. Kolattukudy, PE (1996) Biosynthetic pathways of cutin and waxes, and their sensitivity to environmental stresses. In: Plant Cuticles. Ed. by G. Kerstiens, BIOS Scientific publishers Ltd., Oxford, pp 83-108 Description The plant cuticle is a layer of lipid polymers impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants. It is also present in the sporophyte generation of hornworts, and in both sporophyte and gametophyte generations of mosses. The plant cuticle forms a coherent outer covering of the plant that can be isolated intact by treating plant tissue with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Cell Showing Primary And Secondary Wall By CarolineDahl
Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular, except for some green algae. Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts, mosses, lycophytes, ferns, conifers and other gymnosperm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products (also known as crop protection products), which in general protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent (such as a virus, bacterium, or fungus) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species. Definition The word pesticide derives from the Latin ''pestis'' (plagu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crop Rotation
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. This practice reduces the reliance of crops on one set of nutrients, pest and weed pressure, along with the probability of developing resistant pests and weeds. Growing the same crop in the same place for many years in a row, known as monocropping, gradually depletes the soil of certain nutrients and promotes the proliferation of specialized pest and weed populations adapted to that crop system. Without balancing nutrient use and diversifying pest and weed communities, the productivity of monocultures is highly dependent on external inputs that may be harmful to the soil's fertility. Conversely, a well-designed crop rotation can reduce the need for Fertilizer, synthetic fertilizers and herbicides by better using ecosystem services from a diverse set of crops. Additionally, crop rotations can improve soil structure and Soil organic matter, organic m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Canker
Citrus canker is a disease affecting ''Citrus'' species caused by the bacterium '' Xanthomonas citri''. Infection causes lesions on the leaves, stems, and fruit of citrus trees, including lime, oranges, and grapefruit. While not harmful to humans, canker significantly affects the vitality of citrus trees, causing leaves and fruit to drop prematurely; a fruit infected with canker is safe to eat, but too unsightly to be sold. Citrus canker is mainly a leaf-spotting and rind-blemishing disease, but when conditions are highly favorable, it can cause defoliation, shoot dieback, and fruit drop. The disease, which is believed to have originated in Southeast Asia, is extremely persistent when it becomes established in an area. Citrus groves have been destroyed in attempts to eradicate the disease. Countries like Brazil and the United States also suffer from canker outbreaks. Biology ''Xanthomonas citri'' is a rod-shaped Gram-negative bacterium with polar flagella. The bacterium ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soybean Cyst Nematode
The soybean cyst nematode (SCN), ''Heterodera glycines'', is the most devastating pest to soybean crop yields in the U.S., targeting the roots of soybean and other legume plants. When infection is severe SCNs cause stunting, yellowing, impaired canopy development, and yield loss. The symptoms caused by SCNs can go easily unrecognized by farmers—in some cases there are no warning symptoms before a loss of 40% of the yield.“You can literally have 40% yield loss with no symptoms,” says Greg Tylka, Iowa State University (ISU) Extension nematologist. Due to the slight stunting and yellowing, many farmers may mistake these symptoms as environmental problems when in fact they are SCNs. Another symptom of SCNs that may affect farmers' yields is stunted roots with fewer nitrogen-fixing nodules. Due to the fact that soybean cyst nematodes can only move a few centimeters in the soil by themselves, they mostly are spread via tillage or plant transplants. This area of infection will look ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rice Blast
''Magnaporthe grisea'', also known as rice blast fungus, rice rotten neck, rice seedling blight, blast of rice, oval leaf spot of graminea, pitting disease, ryegrass blast, Johnson spot, neck blast, wheat blast and , is a plant-pathogenic fungus and model organism that causes a serious disease affecting rice. It is now known that ''M. grisea'' consists of a cryptic species complex containing at least two biological species that have clear genetic differences and do not interbreed. Complex members isolated from '' Digitaria'' have been more narrowly defined as ''M. grisea''. The remaining members of the complex isolated from rice and a variety of other hosts have been renamed ''Magnaporthe oryzae'', within the same ''M. grisea'' complex. Confusion on which of these two names to use for the rice blast pathogen remains, as both are now used by different authors. Members of the ''M. grisea'' complex can also infect other agriculturally important cereals including w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
