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Ascomycetes
Sarcoscypha austriaca
Sarcoscypha austriaca
Scientific classification
Kingdom: Fungi
Subkingdom: Dikarya
Phylum: Ascomycota
(Berk 1857) Caval. A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ Dikarya is a Subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota, both of which in general produce Dikaryons -Sm. 1998[1]
Subphyla/Classes
Pezizomycotina [1][4]
Laboulbeniomycetes
Eurotiomycetes
Lecanoromycetes
Leotiomycetes
Pezizomycetes
Sordariomycetes
Dothideomycetes
Lichinomycetes
Arthoniomycetes
Orbilomycetes
"Unplaced orders"
Lahmiales
Medeolariales
Triblidiales
Saccharomycotina
Saccharomycetes
Taphrinomycotina
Neolectomycetes
Pneumocystidomycetes
Schizosaccharomycetes
Taphrinomycetes

Ascomycota is a Division/Phylum of Fungi, and subkingdom Dikarya, whose members are commonly known as the Sac Fungi. Pezizomycotina is a subphylum of the Ascomycota (fungi which form their spores in a sac-like ascus) and is more or less synonymous with the older taxon Euascomycota The Laboulbeniomycetes are a unique group of fungi that are apparent external parasites of Insects and other Arthropods both terrestrial and aquatic Eurotiomycetes are a class of Ascomycetes within the Pezizomycotina Clade. Lecanoromycetes are a class of Pezizomycetes Fungi, commonly known as the Lichens and Rostrate Asci. Leotiomycetes are a class of Ascomycete Fungi. Many of them cause serious plant diseases. Pezizomycetes are a class of Fungi within the phylum Ascomycota. Sordariomycetes is a class of the subdivision Pezizomycotina, which includes ascomycetous fungi. Dothideomycetes is a class of Ascomycete Fungi. It comprises about 50 families 650 genera and 6300 known species Saccharomycotina is a subphylum of the phylum Ascomycota (fungi which form their sexual spores in sac-like asci) and consists of Yeasts - they form Saccharomycetes is a class in the kingdom of Fungi. It contains the order Saccharomycetales, the budding Yeasts Hemiascomycetes is a more Taphrinomycotina is one of three subphyla constituting the Ascomycota (fungi that form their Spores in a sac-like Ascus) and is more or less synonymous Neolecta is a genus of Ascomycetous fungi that have fruiting bodies in the shape of unbranched to lobed bright yellowish orangish to pale yellow-green Pneumocystis pneumonia ( PCP) is a form of Pneumonia caused by the yeast-like Fungus, Pneumocystis jirovecii (Jirovecii is pronounced Schizosaccharomycetes is a class in the kingdom of Fungi. It contains the order Schizosaccharomycetales, the fission Yeasts A phylum ( Plural: phyla) is a Taxonomic rank between Kingdom and above Class. A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ Dikarya is a Subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota, both of which in general produce Dikaryons Characteristically, when reproducing sexually, they produce nonmotile spores in a distinctive type of microscopic cell called an "ascus" (from Greek: ἀσκός (askos), meaning "sac" or "wineskin"). In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly These spores are called ascospores. An ascospore is a Spore contained in an Ascus or that was produced inside an ascus However, some members of the Ascomycota do not reproduce sexually and do not form asci or ascospores. These members are assigned to Ascomycota based upon morphological and/or physiological similarities to ascus-bearing taxa, and in particular by phylogenetic comparisons of DNA sequences. The term morphology in Biology refers to the outward appearance ( Shape, Structure, Colour, Pattern) of an Organism Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known [2][3]

This monophyletic grouping is an extremely significant and successful group of organisms. A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Familiar examples of sac fungi include morels, truffles, brewer's yeast and baker's yeast, Dead Man's Fingers, cup fungi, and the majority of lichens (loosely termed "ascolichens") such as Cladonia. A truffle ( is the valuable and highly sought-after edible Fruiting body of a group of subterranean Ascomycete fungi of the Genus Baker's yeast is the common name for the strains of Yeast commonly used as a Leavening agent in Baking Bread and related products where it converts Xylaria is a genus of ascomycetous fungi commonly found growing on dead wood Cup fungi are fungi ( Ascomycota: family Pezizaceae) which produce a Mushroom that tends to grow in the shape of a "cup" Lichens (ˈlaɪkən or /lɪtʃən/ are symbiotic associations of a Fungus (the mycobiont with a photosynthetic partner (the photobiont also known as Lichens (ˈlaɪkən or /lɪtʃən/ are symbiotic associations of a Fungus (the mycobiont with a photosynthetic partner (the photobiont also known as Cladonia ( cup lichen) is a Genus of Moss -like Lichens in the family Cladoniaceae. Many plant-pathogenic fungi belong to the Ascomycota. Commonly seen examples include apple scab, ergot, black knot, and the powdery mildews. Ergot is the common name of a Fungus in the Genus Claviceps that is parasitic on certain grains and grasses Powdery mildew is a fungal disease that affects a wide range of plants Species of ascomycetes are also popular in the laboratory. Sordaria fimicola, Neurospora crassa and several species of yeasts are used in many genetics and cell biology experiments. Sordaria fimicola is a species of Microscopic Fungus. It is commonly found in the Feces of Herbivores S Neurospora crassa is a type of red bread mold of the phylum Ascomycota. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is See also List of basic cell biology topics. Cell biology (also called cellular biology or formerly cytology, from the Penicillium species on cheeses and in the antibiotic industry are examples of asexual taxa, otherwise known as anamorphs, that belong in the Ascomycota. Penicillium (from Latin penicillus: paintbrush) is a Genus of Ascomyceteous Fungi that includes A taxon (plural taxa) or taxonomic unit, is a name designating an organism or a group of Organisms In Biological nomenclature according to Prior to definitive phylogenetic research, molds such as Penicillium were sometimes classified in an artificial phylum, called the Deuteromycota. Penicillium (from Latin penicillus: paintbrush) is a Genus of Ascomyceteous Fungi that includes

Contents

Ascomycetes versus Ascomycota [4]

In the past, before the recognition of the fungal kingdom, the sac fungi were considered to be a Class, not a Phylum. A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. A phylum ( Plural: phyla) is a Taxonomic rank between Kingdom and above Class. The original collective term for them was "Ascomycetes", a label first coined in the 1800s for a rankless nonlichenized taxon based upon the presence of asci. A taxon (plural taxa) or taxonomic unit, is a name designating an organism or a group of Organisms In Biological nomenclature according to "Ascomycetes" was soon used to include lichenized taxa, and became the standard term, at the class level, for all ascus-bearing species, just as the term "Basidiomycetes" became used for their basidium-bearing counterparts. Basidiomycota is one of two large phyla that together with the Ascomycota, comprise the subkingdom Dikarya, which were in general what were called Elevation of the taxonomic rank of the Ascomycetes resulted in the names Ascomycetae, Ascomycotina, and finally Ascomycota. The names Ascomycota, Ascomycetes, etc. are based upon the term "ascus". Together, the Ascomycota and the Basidiomycota form the subkingdom Dikarya. Dikarya is a Subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota, both of which in general produce Dikaryons The more familiar term, Ascomycetes, is still loosely used, e. g. at fungal forays it is often said of a fungus, such as Peziza, "It is an ascomycete, not a basidiomycete" in reference to their sexual reproductive mode. Peziza is large Genus of Saprophytic cup Fungi that grow on the ground rotting Wood, or Dung. The terms are further abbreviated to "ascos" and "basidos" which are not officially sanctioned technical names.

Modern classification of Ascomycota

There are 3 subphyla:

Commonly used but obsolete morphologically defined class names

Several obsolete class names, based upon morphology, are still used in informal or introductory discussions. Among those based upon the sexual fruitbodies (teleomorphs) are: the Discomycetes which included all species forming apothecia; the Pyrenomycetes which included all sac fungi that formed perithecia or even pseudothecia, or any structure approaching these morphological structures; and the Plectomycetes which included those Ascomycota that formed cleistothecia. Discomycetes is a former taxonomic class of Ascomycete Fungi which contains all of the cup sponge brain and some club-like fungi An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus Sordariomycetes is a class of the subdivision Pezizomycotina, which includes ascomycetous fungi. An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus Hemiascomycetes included the yeasts and yeast-like fungi that are now split between Saccharomycotina and Taphrinomycotina, while the Euascomycetes covered the rest of the Ascomycota, now in the Pezizomycotina and Neolecta in the Taphrinomycotina. Hemiascomycetes is class of Fungi of the the phylum Ascomycota that includes the Yeasts and yeastlike fungi Saccharomycotina is a subphylum of the phylum Ascomycota (fungi which form their sexual spores in sac-like asci) and consists of Yeasts - they form Taphrinomycotina is one of three subphyla constituting the Ascomycota (fungi that form their Spores in a sac-like Ascus) and is more or less synonymous Pezizomycotina is a subphylum of the Ascomycota (fungi which form their spores in a sac-like ascus) and is more or less synonymous with the older taxon Euascomycota Pezizomycotina is a subphylum of the Ascomycota (fungi which form their spores in a sac-like ascus) and is more or less synonymous with the older taxon Euascomycota Neolecta is a genus of Ascomycetous fungi that have fruiting bodies in the shape of unbranched to lobed bright yellowish orangish to pale yellow-green

Some Ascomycota never reproduce sexually, or are not known to produce asci. ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in These are sometimes called "Mitosporic Ascomycota" because of the production of conidia otherwise known as mitospores, and other asexual structures, all collectively called anamorphic taxa. The Mitosporic Ascomycota are a Heterogeneous group of ascomycotic Fungi whose common characteristic is the absence of a Sexual state many of In some classifications these would have been placed in a separate artificial phylum, the Deuteromycota (also known as Fungi Imperfecti). Molecular analyses can now be used to place these genera and species among ascus-bearing taxa (if they are Ascomycota), or amongst other phyla such as the Basidiomycota (if related to them). Basidiomycota is one of two large phyla that together with the Ascomycota, comprise the subkingdom Dikarya, which were in general what were called No mitosporic taxa have been found that form a phylum distinct from the other major phyla of Fungi. Anamorphs are discussed below. However, it is extremely difficult in the absence of molecular analysis to link most anamorphic (asexual morphs) fungi to their teleomorphs (sexual counterparts). There are over 250 years of names available (since Linnaeus' Species Plantarum, 1753) for both asexual and sexual components of the same fungi. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for Species Plantarum ("The Species of Plants" was first published in 1753, as a two-volume work by Carl Linnaeus. For instance the sexual form of the kerosene fungus is known as Amorphotheca resinae while the asexual stage is called Hormoconis resinae. Most anamorphic fungi are Ascomycota, and therefore the obsolete classification of the Deuteromycota is largely that of Ascomycota anamorphs.

The Deuteromycota were classified as Coelomycetes if they produced their conidia in small seed-like, fly-speck sized, flask-shaped conidiomata, or structures resembling or approximating them in structure. Conidia, sometimes termed conidiospores, are asexual, non-motile Spores of a Fungus; they are also called mitospores due The Hyphomycetes were those species where the conidiophores (i. Hyphomycetes is a class of Fungi in the phylum Deuteromycota that lack fruiting bodies e. the hyphae which carry conidia-forming cells on the end) are free or loosely organized. They are mostly isolated but sometimes also appear as bundles of cells aligned in parallel (described as synnematal) or as cushion-shaped masses (described as sporodochial).

Physical make-up

The adjective which describes these fungi is "ascomycetous". The majority of ascomycetous fungi grow as a thallus, called a mycelium, consisting of many hyphae which are microscopic multi-branched filaments. For the chronologer/historian occasionally mentioned in the works of early Christian writers see Thallus (historian. Mycelium (plural mycelia) is the vegetative part of a Fungus, consisting of a mass of branching thread-like Hyphae The mass of hyphae is sometimes called A hypha (plural hyphae) is a long branching filamentous cell of a Fungus, and also of unrelated Actinobacteria. If the hyphae of some typical mycelia were laid end to end, they could reach a length of several kilometers. Ascomycota typically produce great numbers of asci at any one time, and these may be contained in a multicellular, often readily visible structure called an "ascocarp" (also called an "ascoma", the fruiting body of ascomycetes). ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus The sporocarp of a Basidiomycete is known as a Basidiocarp, while the fruiting body of an Ascomycete is known as an Ascocarp. Many exceptions to the structure described above occur, for example in one extreme these fungi are single celled yeasts, and there is no mycelium, no fruitbody, and the entire cell is converted into an ascus in such ascomycetous yeasts such as baker's Yeast (Saccharomyces cerevisiae). Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described Saccharomyces cerevisiae is a Species of Budding Yeast. It is perhaps the most useful Yeast owing to its use since ancient times

In the case of lichenized species, the thallus of the fungus defines the shape of the symbiotic colony. Lichens (ˈlaɪkən or /lɪtʃən/ are symbiotic associations of a Fungus (the mycobiont with a photosynthetic partner (the photobiont also known as This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek Other Ascomycota are dimorphic, which can mean that they can appear either in single- or multi-cellular form. Phenotypic switching (aka phenotypic dimorphism is switching between two cell-types Other species are pleomorphic, exhibiting multiple asexual forms (i. Pleomorphism is the occurrence of two or more structural forms during a life cycle, especially of certain plants e. anamorphs detailed below) as well as a sexual form (a teleomorph). The ascoma come in multiple forms: cup-shaped, club-shaped, potato-like, spongy, seed-like, oozing and pimple-like, coral-like, nit-like, golf-ball-shaped, perforated tennis ball-like, cushion-shaped, plated and feathered in miniature (Laboulbeniales), microscopic classic Greek shield-shaped, stalked or sessile, solitary or clustered, etc. An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus Laboulbeniales is an order of Fungi within the class Lecanoromycetes. They can be fleshy or carbonaceous (like charcoal), leathery, rubbery, gelatinous, slimy, powdery, or cob-web-like, etc. They come in multiple colors such as red, orange, yellow, and rarely green or blue, although brown or black are more common.

Except for lichens, the mycelium (if produced) is usually inconspicuous because it is subterranean or embedded in the substrate, and only the ascoma is seen in season. But spectacular, bizarre, or otherwise noteworthy exceptions occur. Many ascomatous fungi have melanized hyphal walls (referred to as dematiaceous walls) and therefore are black or brown. Melanin is a class of compounds found in the Plant, Animal and Protista kingdoms, where it serves predominantly as a Pigment. Black spots on bathroom caulking are often colonies of Ascomycota, e. g. Cladosporium. Cladosporium is a Genus of fungi including some of the most common indoor and outdoor Molds It produces olive-green to brown or black colonies Many molds that grow on spoiled foods are Ascomycota, and therefore the pellicles or skins that develop on jams, juices, and other foods in containers at home are in fact the thalli of Ascomycota (occasionally Mucoromycotina, and almost never Basidiomycota). WikipediaManual_of_Style#National_varieties_of_English --> Molds (or Basidiomycota is one of two large phyla that together with the Ascomycota, comprise the subkingdom Dikarya, which were in general what were called Sooty molds that develop on plants, especially in the tropics are the thalli of many species.

Sometimes it is the mass of asci or ascus-like cells, or conidia or yeast cells that are the conspicuous elements. Pneumocystis species fill lung cavities causing a form of pneumonia (visible in x-rays). Pneumocystis pneumonia ( PCP) is a form of Pneumonia caused by the yeast-like Fungus, Pneumocystis jirovecii (Jirovecii is pronounced Ascosphaera cysts (asci) fill honey bee larvae and pupae making them appear mummified and chalk-like, hence the name "chalkbrood". ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in This article refers collectively to all true honey bees for the "common" domesticated honey bee see European honey bee Honey bees A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation Free living yeasts form yeast colonies. Excessive Candida yeast growth in the mouth or vagina is called "thrush" or candidiasis. Candida is a Genus of Yeasts Many species of this genus are Endosymbionts Candidiasis, commonly called yeast infection or thrush, is a Fungal infection (mycosis of any of the Candida species of which

The cell walls of these fungi are almost always formed of Chitin and β-Glucans; individual cells are formed from divisions of the hyphae called "septa". Chitin ( C 8 H 13 O 5 N)n (ˈkaɪtən is a long-chain Polymer of a N-acetylglucosamine A septum ( Latin: something that encloses; plural Septa) is a partition separating two cavities or spaces These give stability to the hyphae and prevent a great loss of cytoplasm in the event that the cell membrane should be locally damaged. The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. The cell membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer" is a Selectively permeable Lipid bilayer Mostly the cell divisions are centrally perforated, so they have a small opening in the middle, through which cytoplasm and also nuclei can move more or less freely throughout the system of hyphae. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed Often hyphae have only one nucleus per cell, and are therefore described as uninucleate, but some ascomycetous fungi can also be multinucleate at times. Multinucleate (also multinucleated, coenocytic) cells have more than one nucleus per cell, which is the result of nuclear division not being

The ascocarp of a morel contains numerous apothecia.
The ascocarp of a morel contains numerous apothecia.

Metabolism

Like most fungi the Ascomycota principally digest living or dead biomass. To achieve this, they secrete into their surroundings powerful digestive enzymes which break down organic substances into small molecules, which are then absorbed through the cell wall. Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks Many species live on dead plant material such as fallen leaves, twigs, or logs. Others attack plants, animals, or other fungi as parasites and derive their metabolic energy, as well as all the nutrients they need, from the cell tissue of their hosts. Parasitism is a type of symbiotic relationship between Organisms of different Species. Especially in this group extreme specialization appears; for instance certain species of Laboulbeniales attack only one particular leg of one particular insect species. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Laboulbeniales is an order of Fungi within the class Lecanoromycetes. The Ascomycota also often take up symbiotic relationships – for instance some combine with green algae or cyanobacteria, from which they obtain photosynthetic nutrients, to form lichens; others form symbioses with tree roots as mycorrhizal fungi. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy Lichens (ˈlaɪkən or /lɪtʃən/ are symbiotic associations of a Fungus (the mycobiont with a photosynthetic partner (the photobiont also known as This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek A mycorrhiza (Greek for fungus roots coined by Frank 1885 typically seen in the plural forms mycorrhizae or mycorrhizas) is a symbiotic (occasionally There are also carnivorous fungi, which have developed hyphal traps in which they can catch small protists such as amoebae, as well as roundworms (Nematoda), rotifers, tardigrades, and small arthropods such as springtails (Collembola). Protists (ˈproʊtɨst are a diverse group of eukaryotic Microorganisms Historically protists were treated as the kingdom Protista but this Amoeba (sometimes amœba or ameba, plural amoebae) is a Genus of Protozoa that moves The nematodes or roundworms ( Phylum Nematoda from Greek (nema "thread" + -ode "like" are one of the most common The rotifers make up a Phylum of microscopic and near-microscopic pseudocoelomate Animals They were first described by Rev Tardigrades (commonly known as water bears) form the Phylum Tardigrada, part of the superphylum Ecdysozoa. Springtails ( Collembola) form the largest of the three lineages of modern hexapods that are no longer considered Insects (the other two are the

Through their long evolutionary history the Ascomycota have developed the capability to break down almost every organic substance. Unlike most organisms they are able to use their own enzymes to digest plant cellulose and the lignin contained in wood. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4 Lignin or lignen is a complex Chemical compound most commonly derived from Wood and an integral part of the secondary Cell walls of Plants Collagen, an abundant structural protein in animals, and keratin (which hair is made of), can also serve as food sources. Collagen is the main Protein of Connective tissue in Animals and the most abundant protein in Mammals making up about 50% of the whole-body protein Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds Exotic examples are given by the ascomycete Aureobasidium pullulans, which metabolizes wall paint, and the kerosene fungus Amorphotheca resinae, which (to the misfortune of the airline industry) feeds on aircraft fuel, and in tropical regions sometimes blocks fuel pipes. Others resist osmotic stress to grow on salted fish, and a few live in water. Osmotic pressure is the hydrostatic pressure produced by a difference in concentration between solutions on the two sides of a surface such as a semipermeable membrane

Hypomyces completus on culture medium
Hypomyces completus on culture medium

Distribution and living environment

The Ascomycota are present in all land ecosystems world-wide – they even occur in Antarctica – and their spores and hyphal fragments are distributed through the atmosphere and fresh water environments, as well as ocean beaches and tidal zones. The distribution of individual species is very variable: some are found on all continents, while for example the white truffle Tuber magnatum, which is much sought after for culinary purposes, only appears in isolated locations in Italy and France. A truffle ( is the valuable and highly sought-after edible Fruiting body of a group of subterranean Ascomycete fungi of the Genus Plant parasitic species are often restricted by their host distributions. Cyttaria is only found on Nothofagus (Southern Beech) in the Southern Hemisphere. Cyttaria is a genus of Ascomycete Fungi. At least 20 species and subspecies belong to the Genus Cyttaria found in South America and Australia Nothofagus, also known as the southern beeches, is a genus of about 35 Species of Trees and shrubs native to the temperate oceanic Nothofagus, also known as the southern beeches, is a genus of about 35 Species of Trees and shrubs native to the temperate oceanic Southern Hemisphere is the half of a Planet that is South of the Equator —the word hemisphere literally means 'half ball'

Reproduction

Asexual reproduction

Asexual reproduction is the dominant form of propagation in the Ascomycota, and is responsible for the rapid expansion of these fungi into areas which were previously not colonized. It occurs through reproductive structures, the "conidia," which are genetically identical to the parent and mostly have just one nucleus. Conidia, sometimes termed conidiospores, are asexual, non-motile Spores of a Fungus; they are also called mitospores due They are also called "mitospores" due to the way they are generated through the cellular process of mitosis. Mitosis is the process in which a Eukaryotic cell separates the Chromosomes in its Cell nucleus, into two identical sets in two daughter nuclei They are generally formed on the ends of specialized hyphae, the "conidiophores". A hypha (plural hyphae) is a long branching filamentous cell of a Fungus, and also of unrelated Actinobacteria. Depending on the species they may be dispersed by wind or water, or also by animals.

Asexual spores

In order to further classify the Ascomycota in the asexual stages, it is important to consider the spores, which can be distinguished by colour, form and the way they are separated into cells. The most frequent types are the single-celled spores which are designated amerospores. If the spore is divided into two by a cross-wall (septum), it is a didymospore. A septum ( Latin: something that encloses; plural Septa) is a partition separating two cavities or spaces

Conidiospores of Trichoderma aggressivum, Diameter approx. 3µm
Conidiospores of Trichoderma aggressivum, Diameter approx. 3µm
Conidiophores of molds of the genus Aspergillus, conidiogenesis is blastic-phialidic
Conidiophores of molds of the genus Aspergillus, conidiogenesis is blastic-phialidic
Conidiophores of Trichoderma harzianum, conidiogenesis is blastic-phialidic
Conidiophores of Trichoderma harzianum, conidiogenesis is blastic-phialidic
Conidiophores of Trichoderma fertile with vase-shaped phialides and newly formed conidia on their ends (bright points)
Conidiophores of Trichoderma fertile with vase-shaped phialides and newly formed conidia on their ends (bright points)

When there are two or more cross-walls the classification depends on the shape. Trichoderma harzianum is a Fungus that is also used as a Fungicide. If the septa are transversal, like the rungs of a ladder, it is a phragmospore whilst if they form a net-like structure it is a dictyospore. In staurospores ray-like "arms" radiate from a central body; in others (helicospores) the entire spore is wound up in a spiral like a spring. Finally very long worm-like spores, of which the ratio length:diameter is more than 15:1, are called scolecospores.

Conidiogenesis and dehiscence

One distinguishes:

Mostly they develop a flat layer of relatively short conidiophores which then produce masses of spores. The increasing pressure finally leads to the splitting of the epidermis and cuticle and so allows the conidia to escape.

Two further important characteristics of the anamorphs of the Ascomycota are the conidiogenesis, the fashion in which the spores are formed, and their dehiscence, i. e. how they separate from the parent structures. The former corresponds to Embryology in animals and plants and can be divided into two fundamental forms of development: blastic conidiogenesis, where the spore is already evident before it separates from the conidiogenic hypha which is giving rise to it, and thallic conidiogenesis, where first a cross-wall appears and then the thus created cell develops into a spore. Embryology (from Greek grc ἔμβρυον embryon, "unborn embryo" and grc -λογία -logia) is the study of the development

These two basic types can be further classified as follows.

Essentially dehiscence can happen in two different ways. In the schizolytic variant a double dividing wall with a central lamella (layer) forms between the cells; the central layer dissolves to release the spores. In the case of rhexolytic dehiscence on the other hand the cell wall which joins the spores on the outside simply degenerates and sets free the conidia.

Heterocaryosis and parasexuality

A significant number of Ascomycota species either have no sexual stage or none is known. In spite of this, there are two ways in which they can conserve their genetic diversity: Heterocaryosis and Parasexuality.

The former happens simply through the merging of two hyphae belonging to different individuals, a process known as anastomosis. As a result there are more cell nuclei than normal in the mycelium and they come from genetically different parent organisms. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed Mycelium (plural mycelia) is the vegetative part of a Fungus, consisting of a mass of branching thread-like Hyphae The mass of hyphae is sometimes called

Parasexuality, on the other hand, refers to a phenomenon where two cell nuclei merge without any sexual process and the chromosome count is doubled. A chromosome is an organized structure of DNA and Protein that is found in cells. This involves a complex form of the type of cell division called mitosis, where there is crossing over or recombination, i. Mitosis is the process in which a Eukaryotic cell separates the Chromosomes in its Cell nucleus, into two identical sets in two daughter nuclei Genetic recombination is the process by which a strand of genetic material (usually DNA; but can also be RNA) is broken and then joined to a different DNA molecule e. an exchange of genetic material between corresponding pairs of chromosomes. In sexual reproduction, in contrast, crossing over occurs only during meiosis. In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half Finally the chromosome count will be restored to normal by haploidization, whereby the nucleus splits into two parts each having a single set of chromosomes, with each daughter genetically different from the original parents. "Haplo" redirects here For the fictional character see The Death Gate Cycle.

Sexual reproduction

Ascus of Hypocrea virens with eight two-celled Ascospores
Ascus of Hypocrea virens with eight two-celled Ascospores

Sexual reproduction in the Ascomycota is marked by a characteristic structure, the ascus, which distinguishes these fungi from all others. An ascus is a tube-shaped vessel, a meiosporangium, which contains the sexual spores produced by meiosis. In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half The latter are called ascospores in contrast to the asexual conidiospores.

Apart from exceptions such as baker's Yeast (Saccharomyces cerevisiae), almost all fungi of the Ascomycota are haploid, so their nuclei only contain one set of chromosomes, which makes them especially susceptible to mutations. Saccharomyces cerevisiae is a Species of Budding Yeast. It is perhaps the most useful Yeast owing to its use since ancient times "Haplo" redirects here For the fictional character see The Death Gate Cycle. A chromosome is an organized structure of DNA and Protein that is found in cells. During sexual reproduction there is a diploid phase (with two sets of chromosomes), which as a rule is very short. "Haplo" redirects here For the fictional character see The Death Gate Cycle. Then meiosis occurs, generally very soon, so that the haploid state is re-established.

The formation of sexual spores

The sexual part of the life cycle commences when two suitable hyphae meet each other. These come from the same web of hyphae which can also generate asexual spores. The first deciding factor as to whether conjugation - that is, sexual merging - will occur, is whether the hyphae belong to the same organism, or whether they come from different individual fungi. Whilst many species are thoroughly capable of self-propagation, i. e. they are homothallic, others need non-identical partners and so are heterothallic. Besides this, the two hyphae in question must also belong to the same mating type. Mating types occur in Eukaryotes that undergo Sexual reproduction via Isogamy. Mating types are a peculiarity of the fungi and correspond roughly to the sexes in plants and animals; however one species may have more than two mating types.

In the case of compatibility, gametangia form on the hyphae; these are the generative cells for the gametes, in which numerous nuclei gather. A gamete (from Ancient Greek γαμέτης; translated gamete = wife gametes = husband is a cell that fuses with another gamete A very fine hypha, called the trichogyne, which grows out of one gametangium, now termed the ascogonium, makes a passage to a gametangium of the other individual, which is then the antheridium. Nuclei then pass from the antheridium (playing a 'male' role) to the ascogonium (playing a 'female' role).

Unlike the process in animals and plants, after the union of the cytoplasms of the two gametangia (plasmogamy), the merging of the nuclei (karyogamy) does not usually occur immediately. The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. Instead, the nuclei which have migrated in from the antheridium pair up with the nuclei of the ascogonium, but remain separate next to their partners. With this the dikaryophase of the life cycle begins; during this time the pairs of nuclei repeatedly synchronously divide, so that a great number are produced. In all probability the dikaryophase is an evolutionary adaptation which serves to exploit the potential of sexual reproduction to the full in circumstances where it is a rare event for different individuals to meet each other. After the genetic raw material has been increased by repeated division, recombination will take place independently in each pair during meiosis, so that the greatest possible quantity of genetically different spores will arise. Genetic recombination is the process by which a strand of genetic material (usually DNA; but can also be RNA) is broken and then joined to a different DNA molecule In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half In the red algae (Rhodophyta) a similar solution to the corresponding problem evolved independently. The red algae (Rhodophyta ˌroʊdəˈfaɪtə roʊˈdɒfɨtə from Greek: ῥόδον (rhodon = rose + φυτόν (phyton = plant thus red plant are

Next millions of new dinucleate hyphae, into each of which two nuclei migrate, emerge from the fertilized ascogonium. They are also called ascogenous or fertile. They are fed by ordinary uni- or mononucleate hyphae (with only one nucleus), which are also called sterile. The tissue of sterile and fertile hyphae now grows in many cases into a macroscopically visible fruiting body, the ascocarp, which may contain millions of fertile hyphae. An ascocarp, or ascoma (plural ascomata) is the fruiting body ( Sporocarp) of an Ascomycete fungus

Unitunicate-inoperculate Asci of Hypomyces chrysospermus
Unitunicate-inoperculate Asci of Hypomyces chrysospermus

In the actual fruiting layer, the hymenium, the asci now appear. The hymenium is the tissue layer on the Hymenophore of a Fungal Fruiting body where the cells develop into basidia or asci, which ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in At one end of an ascogenous hypha, there develops a U-shaped hook, which points back opposite to the general growth direction. The two nuclei contained in the terminal cell then divide in such a way that the threads of their mitotic spindles run parallel, and thus two pairs of genetically different daughter nuclei arise, with one daughter of each pair near the point of the hook, and the other in the base part of the hypha. In Cell biology, the spindle apparatus (also called spindle fibers) is the structure that separate the Chromosomes into the daughter cells during Then two parallel cross-walls appear, dividing the hypha into three sections: that at the point of the hook with one nucleus, that at the base of the original hypha with one nucleus, and the middle U-shaped part with two nuclei.

If the positioning in the fruiting layer is right, the karyogamic fusion of the nuclei finally takes place in the U-shaped cell, creating the diploid zygote. For other meanings see Zygote (disambiguation. A zygote (from Greek ζυγωτός zugōtos "joined" or "yoked" It lengthens to form an elongated tube-shaped or cylinder-shaped capsule, the actual ascus. Then meiosis occurs, giving rise to four haploid nuclei. In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half "Haplo" redirects here For the fictional character see The Death Gate Cycle. This is almost always followed by a further mitotic division, so that the ascus ultimately has eight daughter nuclei. Mitosis is the process in which a Eukaryotic cell separates the Chromosomes in its Cell nucleus, into two identical sets in two daughter nuclei These become enclosed, together with some of the cell plasma, each by their own membranes, and generally with a hard cell wall. Thus the dissemination cells (the ascospores) develop, lying initially like peas in a pod inside the ascus. Later, when an appropriate opportunity presents itself, they are liberated.

Not having flagella, ascospores are disseminated in various other ways: some are spread by wind and with others the ripe ascus breaks open on contact with water to set free the spores. A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it Certain species have evolved regular 'spore cannons' which can eject them up to 30 cm. away. When the spores reach a suitable substrate, they germinate, form new hyphae, and so restart their life cycle, which has come full circle.

The form of the ascus is important for classification and is divided into four basic types: unitunicate-operculate, unitunicate-inoperculate, bitunicate, or prototunicate. See the article on asci for further details. ascusgif|thumb|right|Ascus of Saccharomyces cerevisiae containing a tetrad of four spores]]An ascus (plural asci) is the sexual spore-bearing cell produced in

Ecology

The Ascomycota fulfil a central role in most land-based ecosystems. An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical ( They are important decomposers which break down such organic materials as dead leaves, twigs, fallen trees, etc. Decomposers (or Saprotrophs) are organisms that consume dead organisms and in doing so carry out the natural process of Decomposition. and help the detritivores (animals which live off this decomposing material) to obtain their nutrients. Detritivores, also known as detritus feeders or saprophages, are Heterotrophs that obtain Nutrients by consuming Detritus (decomposing By processing substances like cellulose or lignin, which are otherwise difficult to exploit, they take on an important place in the natural nitrogen cycle and the carbon cycle. Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4 Lignin or lignen is a complex Chemical compound most commonly derived from Wood and an integral part of the secondary Cell walls of Plants The nitrogen cycle is the Biogeochemical cycle that describes the transformations of Nitrogen and nitrogen-containing compounds in nature The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the Biosphere, Pedosphere, Geosphere, Hydrosphere, and

Inversely the fruiting bodies of the Ascomycota provide food for a very diverse set of animals from insects and slugs and snails (Gastropoda) to rodents and larger mammals such as deer and wild boars. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described The class Gastropoda or the gastropods, also previously known as gasteropods, or univalves, and more commonly known as Snails Rodentia is an order of Mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must A deer is a Ruminant Mammal belonging to the family Cervidae. The boar or wild boar ( Sus scrofa) is an Omnivorous, gregarious Mammal of the biological family Suidae.

Fungi of the Ascomycota are also known for their numerous symbiotic relationships with other organisms. This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek

Lichens

Cross-section through the lichen Pseudevernia furfuracea with plainly visible layer of green algae under the surface
Cross-section through the lichen Pseudevernia furfuracea with plainly visible layer of green algae under the surface
Pseudevernia furfuracea
Pseudevernia furfuracea

Probably since early in their evolutionary history the Ascomycota have "domesticated" green algae (Chlorophyta), as well as occasionally other types of algae and cyanobacteria. The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy Together they form the mutualistic associations known as lichens, which can survive in the least hospitable regions of the earth, including the Arctic, the Antarctic, deserts and mountaintops, and can withstand temperature extremes from -40°C to +80°C. Lichens (ˈlaɪkən or /lɪtʃən/ are symbiotic associations of a Fungus (the mycobiont with a photosynthetic partner (the photobiont also known as The Arctic is the Region around the Earth 's North Pole, opposite the Antarctic region around the South Pole. A desert is a Landscape or region that receives very little precipitation. While the photoautotrophic algal partner creates metabolic energy through photosynthesis, the fungus offers a stable supportive framework and protects from radiation and drying out. Photoautotrophs or Phototroph ( Gk: photo = light auto = self troph = nourishment are Organisms (commonly plants that carry out Photosynthesis Around 42% of the Ascomycota (numerically about 18,000 species) form lichens, and almost all the fungal partners of lichens belong to the Ascomycota - the proportion of Basidiomycota is probably only two to three percent.

Mycorrhizal fungi and endophytes

Members of the Ascomycota make two particularly important types of relationship with plants: as mycorrhizal fungi and as endophytes. A mycorrhiza (Greek for fungus roots coined by Frank 1885 typically seen in the plural forms mycorrhizae or mycorrhizas) is a symbiotic (occasionally An endophyte is an Endosymbiont, often a Bacterium or Fungus, that lives within a Plant for at least part of its life without causing apparent The former make symbiotic associations with the root systems of the plants, which for some trees, especially conifers, can be of vital importance, enabling the uptake of mineral salts from the soil. This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek The fungal partner is in a much better position to absorb minerals due to its finely divided mycelium, whilst the plant provides it with metabolic energy in the form of photosynthetic products. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. Cases are even known where mycorrhizal fungi can transport nutrients from one plant to another, stabilizing the recipient. It is likely that mycorrhizal associations enabled the conquest of the land by plants - in any case the earliest known fossils of land plants have mycorrhizae.

Endophytes on the other hand live inside plants, especially in the stem and leaves, but generally do not damage their hosts. An endophyte is an Endosymbiont, often a Bacterium or Fungus, that lives within a Plant for at least part of its life without causing apparent The exact nature of the relationship between endophytic fungus and host is not yet well understood, but it seems that this form of colonization can bestow a higher resistance against insects, roundworms (nematodes), and bacteria; also it can enable or augment the production of poisonous alkaloids, chemicals which can affect the health of plant-eating mammals. The nematodes or roundworms ( Phylum Nematoda from Greek (nema "thread" + -ode "like" are one of the most common The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have This article is about the chemical compounds alkaloids For the Pharmaceutical company in the Republic of Macedonia see Alkaloid (company.

Symbiotic relationships with animals

A series of Ascomycota species from the genus Xylaria are found in the nests of leafcutter ants and other fungus-growing ants of the tribe Attini and in the fungal gardens of termites (Isoptera). Leafcutter ants are social Insects found in warmer regions of the Americas. The fungus-growing ants (tribe Attini comprises all the known Fungus -growing Ant species in the world participating in Ant-fungus mutualism The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy Since they do not generate fruiting bodies until the insects have left the nests, it is suspected that, as confirmed in several cases of Basidiomycota species, they may be cultivated. Basidiomycota is one of two large phyla that together with the Ascomycota, comprise the subkingdom Dikarya, which were in general what were called

On the other hand bark beetles (Scolytidae) are certainly important symbiotic partners. A bark beetle is one of approximately 220 Genera with 6000 Species of Beetles in the Subfamily Scolytinae. The female beetles transport the spores to new hosts in characteristic tucks in their skin, the mycetangia. There they eat tunnels in the wood, which lead into large chambers in which they lay their eggs. At this time the spores are released and give rise to hyphae which unlike the beetles can digest the wood. The beetle larvae feed on the fungus and after they have metamorphosed into the adult state they again carry spores with them to renew the cycle of infection. A well-known example of this is Dutch elm disease, caused by fungus Ophiostoma ulmi, being carried by the European elm bark beetle Scolytus multistriatus. Dutch elm disease (DED is a fungal disease of Elm trees which is spread by the Elm bark beetle.

Importance for humans

Tree attacked by the Bluestain fungus, Ophiostoma minus
Tree attacked by the Bluestain fungus, Ophiostoma minus

Ascomycetes make many contributions to the good of humanity, and also have many ill effects.

Harmful interactions

One of their most harmful roles is as the agent of many plant diseases. For instance:

Claviceps purpurea on rye (Secale cereale)
Claviceps purpurea on rye (Secale cereale)

Positive effects

On the other hand, ascus fungi have brought some important benefits to humanity.

Stilton cheese veined with Penicillium roqueforti
Stilton cheese veined with Penicillium roqueforti

Notes

  1. a  (Taylor, Spatafora & Berbee 1996) and reference 4.
  2. b  The taxonomic system used here (based on reference 1) is only one among several; another authoritative one is given by references 2 & 3.
  3. d  See reference 5.

Linked references

  1. ^ Cavalier-Smith, T. (1998). "A revised six-kingdom system of Life". Biol. Rev. Camb. Philos. Soc. 73 (3): 203-266. The Cambridge Philosophical Society (CPS is a scientific society at University of Cambridge.  
  2. ^ Lutzoni F, et al (2004). "Assembling the fungal tree of life: progress, classification, and evolution of subcellular traits". Amer J Bot 91: 1446-1480. doi:10.3732/ajb.91.10.1446. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  3. ^ James TY et al (2006). "Reconstructing the early evolution of Fungi using a six-gene phylogeny". Nature 443: 818-822. doi:10.1038/nature05110. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17051209.  

Unlinked references

  1. Taylor, John W. ; Joey Spatafora & Mary Berbee (March 11, 1996), "Ascomycota", Tree of Life, <http://tolweb.org/Ascomycota>. Events 1425 BC - Thutmose III, Pharaoh of Egypt, dies (according to the Low Chronology of the 18th Dynasty Year 1996 ( MCMXCVI) was a Leap year starting on Monday (link will display full 1996 Gregorian calendar)
  2. Ainsworth and Bisby's Dictionary of the Fungi, 9th Edition, see here for more details.
  3. See the Index Fungorum (Hierarchy Search) for a web search based on the previous reference.
  1. Outline of Ascomycota - 2001
  2. Palæos Fungi
  3. C. J. Alexopoulos, M. Blackwell, C. W. Mims: Introductory Mycology, 4th Ed. , 1996, ISBN 0-471-52229-5
  4. B. Kendrick: "The Fifth Kingdom, 3rd Ed. , 2001, Kapitel 4, ISBN 1-58510-022-6
  5. G. J. Krieglsteiner: Verbreitungsatlas der Großpilze Deutschlands (West), Volume 2: Schlauchpilze, Ulmer Verlag, 1993
  6. F. Breitenbach, J. Kränzlin: Pilze der Schweiz, Volume 1, Ascomycetes, Mykologia Luzern, 1984
  7. Anamorph-Teleomorph-Datenbank
  8. Fotografien einiger Fruchtkörper (Ascomata)

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