|
Urediniomycetes
The Pucciniomycetes (formerly known as the Urediniomycetes) are a class of fungi in the Pucciniomycotina subdivision of the Basidiomycota. The class contains 5 orders, 21 families, 190 genera, and 8016 species. It includes several important plant pathogens causing forms of fungal rust. Characteristics Pucciniomycetes develop no basidiocarp, karyogamy occurs in a thick-walled resting spore (teliospore), and meiosis occurs upon germination of teliospore. They have simple septal pores without membrane caps and disc-like spindle pole bodies. Except for a few species, the basidia, when present, are transversally septate. Mannose is the major cell wall carbohydrate, glucose, fucose Fucose is a hexose deoxy sugar with the chemical formula C6H12O5. It is found on ''N''-linked glycans on the mammalian, insect and plant cell surface. Fucose is the fundamental sub-unit of the seaweed polysaccharide fucoidan. The α(1→3) li ... and rhamnose are the less prevalent neutral s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basidiocarp
In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures. As with other sporocarps, epigeous (above-ground) basidiocarps that are visible to the naked eye (especially those with a more or less agaricoid morphology) are commonly referred to as mushrooms, while hypogeous (underground) basidiocarps are usually called false truffles. Structure All basidiocarps serve as the structure on which the hymenium is produced. Basidia are found on the surface of the hymenium, and the basidia ultimately produce spores. In its simplest form, a basidiocarp consists of an undifferentiated fruiting structure with a hymenium on the surface; such a structure is characteristic of many simple jelly and club fungi. In more complex basidiocarps, there is differentiation into a stipe, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pucciniomycotina
Pucciniomycotina is a subdivision of fungus within the division Basidiomycota. The subdivision contains 9 classes, 20 orders, and 37 families. Over 8400 species of Pucciniomycotina have been described - more than 8% of all described fungi. The subdivision is considered a sister group to Ustilaginomycotina and Agaricomycotina, which may share the basal lineage of Basidiomycota, although this is uncertain due to low support for placement between the three groups. The group was known as Urediniomycetes until 2006, when it was elevated from a class to a subdivision and named after the largest order in the group, Pucciniales. Ecology Pucciniomycotina have a diverse range of ecologies as insect parasites, mycoparasites, and orchid mycorrhiza; some have been detected in soil and water or asymptotic members living on leaves. Most are plant pathogens. Many Pucciniomycotina are rust fungi and are placed in the order Puccinales that contains roughly 7800 species (c. 90% of the group). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teliospore
Teliospore (sometimes called teleutospore) is the thick-walled resting spore of some fungi ( rusts and smuts), from which the basidium arises. Development They develop in '' telia'' (sing. ''telium'' or ''teliosorus''). The telial host is the primary host in heteroecious rusts. The aecial host is the alternate host (look for pycnia and aecia). These terms apply when two hosts are required by a heteroecious rust fungus to complete its life cycle. Morphology Teliospores consist of one, two or more dikaryote cells. Teliospores are often dark-coloured and thick-walled, especially in species where they overwinter (acting as chlamydospores). Two-celled teliospores formerly defined the genus '' Puccinia''. Here the wall is particularly thick at the tip of the terminal cell which extends into a beak in some species. Teliospores consist of dikaryote cells. As the teliospore cells germinate, the nuclei undergo karyogamy and thereafter meiosis, giving rise to a four-celled basi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puccinia Sessilis
''Puccinia sessilis'' is a fungal plant pathogen, also known as arum rust or ramsons rust. It commonly infects ''Arum maculatum'' and ''Allium ursinum'' causing yellow to orange circular patches on leaves. On the underside it produces raised orange aecia commonly covered in spores. It is common in Eurasia in the spring. Other species affected by this rust include ''Convallaria majalis'', ''Dactylorhiza fuchsii'', ''Dactylorhiza incarnata'', ''Dactylorhiza majalis'', ''Gymnadenia conopsea'', ''Neottia ovata'', ''Paris quadrifolia'' and ''Phalaris arundinacea'' A specialised form, ''Puccinia sessilis'' f.sp. ''narcissi-orchidacearum'' Boerema & Kesteren ('' Aecidium narcissi'') is a cause of rust in daffodils ('' Narcissus'') and various wild Orchidaceae Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnose
Rhamnose (Rha, Rham) is a naturally occurring deoxy sugar. It can be classified as either a methyl-pentose or a 6-deoxy- hexose. Rhamnose predominantly occurs in nature in its L-form as L-rhamnose (6-deoxy-L-mannose). This is unusual, since most of the naturally occurring sugars are in D-form. Exceptions are the methyl pentoses L- fucose and L-rhamnose and the pentose L-arabinose. However, examples of naturally-occurring D-rhamnose include some species of bacteria, such as ''Pseudomonas aeruginosa'' and '' Helicobacter pylori''. Rhamnose can be isolated from Buckthorn (''Rhamnus''), poison sumac, and plants in the genus '' Uncaria''. Rhamnose is also produced by microalgae belonging to class Bacillariophyceae (diatoms). Rhamnose is commonly bound to other sugars in nature. It is a common glycone component of glycosides from many plants. Rhamnose is also a component of the outer cell membrane of acid-fast bacteria in the ''Mycobacterium'' genus, which includes the organism th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fucose
Fucose is a hexose deoxy sugar with the chemical formula C6H12O5. It is found on ''N''-linked glycans on the mammalian, insect and plant cell surface. Fucose is the fundamental sub-unit of the seaweed polysaccharide fucoidan. The α(1→3) linked core of fucose is a suspected carbohydrate antigen for IgE-mediated allergy. Two structural features distinguish fucose from other six-carbon sugars present in mammals: the lack of a hydroxyl group on the carbon at the 6-position (C-6) (thereby making it a deoxy sugar) and the L -configuration. It is equivalent to 6-deoxy--galactose. In the fucose-containing glycan structures, fucosylated glycans, fucose can exist as a terminal modification or serve as an attachment point for adding other sugars. In human ''N''-linked glycans, fucose is most commonly linked α-1,6 to the reducing terminal β-''N''-acetylglucosamine. However, fucose at the non-reducing termini linked α-1,2 to galactose forms the H antigen, the substructure of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) fo ... [...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] |
Mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation are associated with mutations in enzymes involved in mannose metabolism. Mannose is not an essential nutrient; it can be produced in the human body from glucose, or converted into glucose. Mannose provides 2–5 kcal/g. It is partially excreted in the urine. Etymology The root of both "mannose" and "mannitol" is manna, which the Bible describes as the food supplied to the Israelites during their journey in the region of Sinai. Several trees and shrubs can produce a substance called manna, such as the "manna tree" ('' Fraxinus ornus'') from whose secretions mannitol was originally isolated. Structure Mannose commonly exists as two different-sized rings, the pyranose (six-membered) form and the furanose (five-membered) form. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basidium
A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-coiled secondary myceliuma dikaryon. The presence of basidia is one of the main characteristic features of the Basidiomycota. A basidium usually bears four sexual spores called basidiospores; occasionally the number may be two or even eight. In a typical basidium, each basidiospore is borne at the tip of a narrow prong or horn called a sterigma (), and is forcibly discharged upon maturity. The word ''basidium'' literally means "little pedestal", from the way in which the basidium supports the spores. However, some biologists suggest that the structure more closely resembles a club. An immature basidium is known as a basidiole. Structure Most basidiomycota have single celled basidia (holobasidia), but in some groups basidia can be mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule Organizing Center
The microtubule-organizing center (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. MTOCs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division. The MTOC is a major site of microtubule nucleation and can be visualized in cells by immunohistochemical detection of γ-tubulin. The morphological characteristics of MTOCs vary between the different phyla and kingdoms. In animals, the two most important types of MTOCs are 1) the basal bodies associated with cilia and flagella and 2) the centrosome associated with spindle formation. Organization Microtubule-organizing centers function as the site where microtubule formation begins, as well as a location where free-ends of microtubules attract to. Within the cells, microtubule-organizing centers can take on many different forms. An array of microtubules can arrange themse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitotic Spindle
In cell biology, the spindle apparatus refers to the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a process that produces genetically identical daughter cells, or the meiotic spindle during meiosis, a process that produces gametes with half the number of chromosomes of the parent cell. Besides chromosomes, the spindle apparatus is composed of hundreds of proteins. Microtubules comprise the most abundant components of the machinery. Spindle structure Attachment of microtubules to chromosomes is mediated by kinetochores, which actively monitor spindle formation and prevent premature anaphase onset. Microtubule polymerization and depolymerization dynamic drive chromosome congression. Depolymerization of microtubules generates tension at kinetochores; bipolar attachment of sister kinetochores to microtubules emanating from opposite cell pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
