|
Pythium Sulcatum
''Pythium sulcatum'' is a chromalveolate Plant pathology, plant pathogen infecting carrots. Because this organism was once thought to be a type of fungus, it is still often treated as such. Host and symptoms ''Pythium sulcatum'' causes diseases predominately on members of the apiaceous family, the most common being the carrot. This pathogen causes cavity spots which are sunken, spherical to elliptical oriented, brown-black spots across the breadth of the surface of the carrot. These cavity spots are normally 1-10 mm in width and are often surrounded by a pale halo. The lesions enlarge as the roots mature, often most prominent around the time the crop is harvested. This pathogen is believed to be native of the apiaceous family that eventually became pathogenic to carrots. ''P. sulcatum'' is also seen to cause damping off, taproot dieback, root rotting, Stunt (botany), stunting, and forking of carrots, with cavity spots being the most common of these diseases. Because carrots ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oospore
An oospore is a thick-walled sexual spore that develops from a fertilized oosphere in some algae, fungi, and oomycetes. They are believed to have evolved either through the Somatic fusion, fusion of two species or the chemically-induced stimulation of mycelia, leading to oospore formation. In Oomycetes, oospores can also result from asexual reproduction, by apomixis. These are found in fungi as sexual spores which help the sexual reproduction of fungi. These haploid, non-motile spores are the site of meiosis and karyogamy in oomycetes. A dormant oospore, when observed under an electron microscope, has led researchers to draw conclusion that there is only a single central globule with other storage bodies surrounding it. References Reproduction {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moist Soil
__NOTOC__ Moist, describing the presence of moisture, may refer to: Music * Moist (band), a Canadian alternative rock band * "Moist", a song by Janet Jackson from her 2004 album ''Damita Jo'' People * Lewis Moist (1881–1940), British Olympic swimmer * Paul Moist, Canadian union leader Other uses * Moist, a fictional character from Joss Whedon's ''Dr. Horrible's Sing-Along Blog'' * Moist von Lipwig, a fictional character in Terry Pratchett's ''Discworld'' series * Moists (or Mohists), followers of the Chinese philosophy called Mohism Mohism or Moism (, ) was an ancient Chinese philosophy of ethics and logic, rational thought, and science developed by the academic scholars who studied under the ancient Chinese philosopher Mozi (c. 470 BC – c. 391 BC), embodied in an epon ... (or Moism) See also * {{disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectin Methylesterase
Pectinesterase (EC 3.1.1.11; systematic name pectin pectylhydrolase) is a ubiquitous cell-wall-associated enzyme that presents several isoforms that facilitate plant cell wall modification and subsequent breakdown. It catalyzes the following reaction: :pectin + ''n'' H2O = ''n'' methanol + pectate It is found in all higher plants as well as in some bacteria and fungi. Pectinesterase functions primarily by altering the localised pH of the cell wall resulting in alterations in cell wall integrity. Pectinesterase catalyses the de-esterification of pectin into pectate and methanol. Pectin is one of the main components of the plant cell wall. In plants, pectinesterase plays an important role in cell wall metabolism during fruit ripening. In plant bacterial pathogens such as ''Erwinia carotovora'' and in fungal pathogens such as ''Aspergillus niger'', pectinesterase is involved in maceration and soft-rotting of plant tissue. Plant pectinesterases are regulated by pectinesterase inh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulase
Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides: : Endohydrolysis of (1→4)-β-D-glucosidic linkages in cellulose, lichenin and cereal β-D-glucan The name is also used for any naturally occurring mixture or complex of various such enzymes, that act serially or synergistically to decompose cellulosic material. Cellulases break down the cellulose molecule into monosaccharides ("simple sugars") such as β-glucose, or shorter polysaccharides and oligosaccharides. Cellulose breakdown is of considerable economic importance, because it makes a major constituent of plants available for consumption and use in chemical reactions. The specific reaction involved is the hydrolysis of the 1,4-β-D- glycosidic linkages in cellulose, hemicellulose, lichenin, and cereal β-D-glucans. Because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactate Lyase
{{disambiguation ...
Lactate may refer to: * Lactation, the secretion of milk from the mammary glands * Lactate, the conjugate base of lactic acid Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectin Lyase
Pectin lyase (), also known as pectolyase, is a naturally occurring pectinase, a type of enzyme that degrades pectin. It is produced commercially for the food industry from fungi and used to destroy residual fruit starch, known as pectin, in wine and cider. In plant cell culture, it is used in combination with the enzyme cellulase to generate protoplasts by degrading the plant cell walls. Pectin lyase catalyzes the following process: :Eliminative cleavage of (1→4)-α-D-alacturonan methyl ester to give oligosaccharides with 4-deoxy-6-''O''-methyl-α,-D-galact-4-enuronosyl groups at their non-reducing ends This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on polysaccharides. Nomenclature The systematic name of this enzyme class is (1→4)-6-''O''-methyl-α-D-galacturonan lyase. Other names in common use include: * endo-pectin lyase, * pectin methyltranseliminase, * pectin trans-eliminase, * pectolyase, * PL, * PMGL, * PNL, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygalacturonase
Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glycanohydrolase; systematic name (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)) is an enzyme that hydrolyzes the α-1,4 glycosidic bonds between galacturonic acid residues: :(1,4-α-D-galacturonosyl)''n''+''m'' + H2O = (1,4-α-D-galacturonosyl)''n'' + (1,4-α-D-galacturonosyl)''m'' Polygalacturonan, whose major component is galacturonic acid, is a significant carbohydrate component of the pectin network that comprises plant cell walls. Therefore, the activity of the endogenous plant PGs works to soften and sweeten fruit during the ripening process. Similarly, phytopathogens use PGs as a means to weaken the pectin network, so that digestive enzymes can be excreted into the plant host to acquire nutrients. Structure This enzyme's multiple parallel β sheets form a helical shape that is called a β helix. This highly stable structure, thanks to n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. The composition of cell walls varies between taxonomic group and species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periderm
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the tissues outside the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner bark, which in older stems is living tissue, includes the innermost layer of the periderm. The outer bark on older stems includes the dead tissue on the surface of the stems, along with parts of the outermost periderm and all the tissues on the outer side of the periderm. The outer bark on trees which lies external to the living periderm is also called the rhytidome. Products derived from bark include bark shingle siding and wall coverings, spices and other flavorings, tanbark for tannin, resin, latex, medicines, poisons, various hallucinogenic chemicals and cork. Bark has been used to make cloth, canoes, and ropes and used as a surface for paintings and map making. A number of plants ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Exudate
Plant root exudates are fluids emitted through the roots of plants. These secretions influence the rhizosphere around the roots to inhibit harmful microbes and promote the grow of self and kin plants. Plant root systems can grow to be complex due to a variety of species and microorganisms existing in a common soil. Plants have adapted to respond to the soil conditions and presence of microbes through various mechanisms, one of which is the secretion of root exudates. This secretion allows plants to largely influence the rhizosphere as well as the organisms that exist within it. The contents of exudates and the amount of substance released is reliant on multiple factors, including the root system architecture, presence of harmful microbes, and metal toxicity. The species of the plant as well as its developmental stage can also influence the chemical mixture that is released through exudates. The contents may include ions, carbon-based compounds, amino acids, sterols, and many other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria, and sometimes nuclei to flow between cells. The major structural polymer in fungal cell walls is typically chitin, in contrast to plants and oomycetes that have cellulosic cell walls. Some fungi have aseptate hyphae, meaning their hyphae are not partitioned by septa. Hyphae have an average diameter of 4–6 µm. Growth Hyphae grow at their tips. During tip growth, cell walls are extended by the external assembly and polymerization of cell wall components, and the internal production of new cell membran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oogonia
An oogonium (plural oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in large numbers by mitosis early in fetal development from primordial germ cells. In humans they start to develop between weeks 4 and 8 and are present in the fetus between weeks 5 and 30. Structure Normal oogonia in human ovaries are spherical or ovoid in shape and are found amongst neighboring somatic cells and oocytes at different phases of development. Oogonia can be distinguished from neighboring somatic cells, under an electron microscope, by observing their nuclei. Oogonial nuclei contain randomly dispersed fibrillar and granular material whereas the somatic cells have a more condensed nucleus that creates a darker outline under the microscope. Oogonial nuclei also contain dense prominent nucleoli. The chromosomal material in the nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Oogonia")