Fungus

A fungus (: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which, by one traditional classification, includes Plantae, Animalia, Protozoa, and Chromista.

A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.

Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.

The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.

## Etymology

The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').

The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.

A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.

## Characteristics

Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:

Shared features:

- With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).
- With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.
- With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.
- With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.
- The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.
- In common with some plant and animal species, more than one hundred fungal species display bioluminescence.

Unique features:

- Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.
- The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.

Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.

## Diversity

Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.

`As of 2020,`<sup>`[update]`</sup>` around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species. The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown. The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.`

## Mycology

Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.

The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.

### History

Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.

## Morphology

### Microscopic structures

Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 μm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.

Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla, and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.

Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.

### Macroscopic structures

Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.

The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.

## Growth and physiology

The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues. The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi). The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.

The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.

The fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO<sub>2</sub> fixation via visible light, but instead uses ionizing radiation as a source of energy.

## Reproduction

Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.

### Asexual reproduction

Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.

### Sexual reproduction

Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.

Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).

In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.

Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).

In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.

### Spore dispersal

The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances. Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.

### Homothallism

In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.

### Other sexual processes

Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.

## Evolution

In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.

The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.

In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (\~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).

Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.

Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.

Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".

## Taxonomy

Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.

There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).

The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.

### Taxonomic groups

The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycota, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.

Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.

The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.

The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.

The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.

Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.

The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).

Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.

### Fungus-like organisms

Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.

Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.

The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.

The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.

The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.

## Ecology

Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.

### Symbiosis

Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.

#### With plants

Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.

The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.

#### With algae and cyanobacteria

Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.

#### With insects

Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.

#### As pathogens and parasites

Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.

Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.

#### As targets of mycoparasites

Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.

### Communication

There appears to be electrical communication between fungi in word-like components according to spiking characteristics.

### Possible impact on climate

According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel Greenhouse gas emissions.

## Mycotoxins

Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.

Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.

## Pathogenic mechanisms

Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.

Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.

## Human use

The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.

### Therapeutic uses

#### Modern chemotherapeutics

Many species produce metabolites that are major sources of pharmacologically active drugs.

##### Antibiotics

Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.

##### Other

Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.

### Traditional medicine

Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.

### Cultured foods

Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso, while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.

### In food

Edible mushrooms include commercially raised and wild-harvested fungi. Agaricus bisporus, sold as button mushrooms when small or Portobello mushrooms when larger, is the most widely cultivated species in the West, used in salads, soups, and many other dishes. Many Asian fungi are commercially grown and have increased in popularity in the West. They are often available fresh in grocery stores and markets, including straw mushrooms (Volvariella volvacea), oyster mushrooms (Pleurotus ostreatus), shiitakes (Lentinula edodes), and enokitake (Flammulina spp.).

Many other mushroom species are harvested from the wild for personal consumption or commercial sale. Milk mushrooms, morels, chanterelles, truffles, black trumpets, and porcini mushrooms (Boletus edulis) (also known as king boletes) demand a high price on the market. They are often used in gourmet dishes.

Certain types of cheeses require inoculation of milk curds with fungal species that impart a unique flavor and texture to the cheese. Examples include the blue color in cheeses such as Stilton or Roquefort, which are made by inoculation with Penicillium roqueforti. Molds used in cheese production are non-toxic and are thus safe for human consumption; however, mycotoxins (e.g., aflatoxins, roquefortine C, patulin, or others) may accumulate because of growth of other fungi during cheese ripening or storage.

### Poisonous fungi

Many mushroom species are poisonous to humans and cause a range of reactions including slight digestive problems, allergic reactions, hallucinations, severe organ failure, and death. Genera with mushrooms containing deadly toxins include Conocybe, Galerina, Lepiota and the most infamous, Amanita. The latter genus includes the destroying angel (A. virosa) and the death cap (A. phalloides), the most common cause of deadly mushroom poisoning. The false morel (Gyromitra esculenta) is occasionally considered a delicacy when cooked, yet can be highly toxic when eaten raw. Tricholoma equestre was considered edible until it was implicated in serious poisonings causing rhabdomyolysis. Fly agaric mushrooms (Amanita muscaria) also cause occasional non-fatal poisonings, mostly as a result of ingestion for its hallucinogenic properties. Historically, fly agaric was used by different peoples in Europe and Asia and its present usage for religious or shamanic purposes is reported from some ethnic groups such as the Koryak people of northeastern Siberia.

As it is difficult to accurately identify a safe mushroom without proper training and knowledge, it is often advised to assume that a wild mushroom is poisonous and not to consume it.

### Pest control

In agriculture, fungi may be useful if they actively compete for nutrients and space with pathogenic microorganisms such as bacteria or other fungi via the competitive exclusion principle, or if they are parasites of these pathogens. For example, certain species eliminate or suppress the growth of harmful plant pathogens, such as insects, mites, weeds, nematodes, and other fungi that cause diseases of important crop plants. This has generated strong interest in practical applications that use these fungi in the biological control of these agricultural pests. Entomopathogenic fungi can be used as biopesticides, as they actively kill insects. Examples that have been used as biological insecticides are Beauveria bassiana, Metarhizium spp., Hirsutella spp., Paecilomyces (Isaria) spp., and Lecanicillium lecanii. Endophytic fungi of grasses of the genus Epichloë, such as E. coenophiala, produce alkaloids that are toxic to a range of invertebrate and vertebrate herbivores. These alkaloids protect grass plants from herbivory, but several endophyte alkaloids can poison grazing animals, such as cattle and sheep. Infecting cultivars of pasture or forage grasses with Epichloë endophytes is one approach being used in grass breeding programs; the fungal strains are selected for producing only alkaloids that increase resistance to herbivores such as insects, while being non-toxic to livestock.

### Bioremediation

Certain fungi, in particular white-rot fungi, can degrade insecticides, herbicides, pentachlorophenol, creosote, coal tars, and heavy fuels and turn them into carbon dioxide, water, and basic elements. Fungi have been shown to biomineralize uranium oxides, suggesting they may have application in the bioremediation of radioactively polluted sites.

### Model organisms

Several pivotal discoveries in biology were made by researchers using fungi as model organisms, that is, fungi that grow and sexually reproduce rapidly in the laboratory. For example, the one gene-one enzyme hypothesis was formulated by scientists using the bread mold Neurospora crassa to test their biochemical theories. Other important model fungi are Aspergillus nidulans and the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, each of which with a long history of use to investigate issues in eukaryotic cell biology and genetics, such as cell cycle regulation, chromatin structure, and gene regulation. Other fungal models have emerged that address specific biological questions relevant to medicine, plant pathology, and industrial uses; examples include Candida albicans, a dimorphic, opportunistic human pathogen, Magnaporthe grisea, a plant pathogen, and Pichia pastoris, a yeast widely used for eukaryotic protein production.

### Others

Fungi are used extensively to produce industrial chemicals like citric, gluconic, lactic, and malic acids, and industrial enzymes, such as lipases used in biological detergents, cellulases used in making cellulosic ethanol and stonewashed jeans, and amylases, invertases, proteases and xylanases.

## See also

- Conservation of fungi
- Fantastic Fungi
- Glossary of mycology
- Marine fungi
- Fungal infection
- Outline of fungi
- Fungi in art

Biological kingdom, separate from plants and animals


2007 ACC Championship Game

The 2007 Dr. Pepper ACC Championship Game featured the Boston College Eagles and the Virginia Tech Hokies in a regular-season college football game that determined the conference's champion for the 2007 season. Virginia Tech defeated Boston College 30–16 to win the ACC football championship. The game, held at Jacksonville Municipal Stadium in Jacksonville, Florida, was a rematch of a regular-season game that took place on October 25, in Blacksburg, Virginia. In that game, Boston College, courtesy of a late-game comeback by quarterback Matt Ryan, won 14–10.

Following the loss, Virginia Tech won five straight games to win the Coastal Division of the ACC, while Boston College stumbled, losing two games before defeating the Clemson Tigers to win the Atlantic Division and representation in the Championship Game. Most pre-game media coverage of the event cast the game as an opportunity for Virginia Tech to avenge its earlier loss. In addition, the winner of the game would be awarded an automatic bid to the Bowl Championship Series 2008 Orange Bowl game in Miami, Florida on January 3, 2008. Despite Boston College's earlier win over Virginia Tech, spread bettors favored Virginia Tech by five points.

In the opening quarter of the game, the Eagles took a 7–0 lead on a 51-yard fumble return for a touchdown. The Eagles' offense dominated the first half of the game statistically, but failed to add to its early lead until the second quarter, when a field goal made it 10–0. Virginia Tech answered with a touchdown of their own, but Boston College responded with a seven-play, 74-yard touchdown drive of its own. Then came perhaps the most pivotal play of the game. During the extra point kick following the Boston College touchdown, Virginia Tech's Duane Brown blocked the kick, which was caught by the Hokies' cornerback Brandon Flowers, who returned it 75 yards for a defensive two-point conversion.

The play changed the momentum of the game. Virginia Tech added a tying touchdown before halftime, and after a scoreless third quarter, two Matt Ryan interceptions resulted in 14 points for Virginia Tech and a 30–16 Virginia Tech win. With the victory, the Hokies earned their second Atlantic Coast Conference football championship in four years and their first Orange Bowl bid since 1996.

## Background

The ACC Championship Game matches the winner of the Coastal and Atlantic Divisions of the Atlantic Coast Conference. A conference championship game was added in 2005, as a result of the league's expansion the previous year, adding former Big East members Miami, Virginia Tech, and Boston College. With the addition of Boston College, the ACC consisted of 12 teams, allowing it to hold a conference championship game under NCAA rules.

Florida State defeated Virginia Tech, 27–22 in the first ACC Championship game. The following year, the game, held in Jacksonville, Florida, pitted Wake Forest against Georgia Tech, with Wake Forest winning 9–6. Before the 2007 season began, most sports writers and pollsters predicted Florida State would win the Atlantic Division while Virginia Tech would win the Coastal Division, setting up a rematch of the 2005 ACC Championship Game.

In October, Florida State lost back-to-back ACC conference games to Wake Forest and Miami, eliminating them from contention for their division title. Boston College, which had finished second in the preseason Atlantic Division poll, was ranked No. 2 in the country after Florida State's loss to Miami. Virginia Tech, which suffered a 48–7 defeat at the hands of then-No. 2 LSU, nevertheless remained at the top of the Coastal Division standings as the Eagles passed the Seminoles for the Atlantic Division lead.

On October 25, Boston College traveled to Blacksburg, Virginia, home of Virginia Tech, for a Thursday night game broadcast on ESPN. In heavy rain, Virginia Tech's defense dominated for most of the game. As time ran down, however, Boston College quarterback Matt Ryan orchestrated two late-game touchdown drives, scoring 14 points in the final 2 minutes to win 14–10. The victory seemingly sealed Boston College's route to a national championship game, while the loss potentially jeopardized Virginia Tech's chances of being selected to play in the ACC Championship Game. Over the next two weeks, however, Boston College was upset by Florida State and Maryland. The Eagles rallied to win their final two games—against Miami and Clemson—to clinch the division title. Virginia Tech, meanwhile, was undefeated through the remainder of its schedule, including a division-clinching win over its archrival, Virginia. This meant the ACC Championship Game in Jacksonville would be a rematch between these two division champions.

## Pre-game buildup

In the weeks leading up to the game, there was much media discussion of the future site of the game due to Jacksonville's expiring contract to host the ACC Championship. The media also discussed whether Virginia Tech would be out for revenge against Boston College after its last-second defeat in Blacksburg on October 25. Despite its previous loss, spread bettors favored Virginia Tech to win the game, with most favoring the Hokies by 4.5–5 points.

The game was the 15th contest between Boston College and Virginia Tech and was their second of the 2007 season. The first meeting, which took place in 1993 in the Big East conference, resulted in a 48–34 Boston College win. Between 1993 and 2003, Boston College and Virginia Tech played annually as part of their conference schedules. The teams did not meet in 2004 following Virginia Tech's move to the Atlantic Coast Conference. When Boston College followed in 2005, the schools resumed meeting during the regular season, playing in 2005, 2006, and 2007.

### Off-field issues

Following the 2006 ACC Championship Game, the Gator Bowl Association, which administered the ACC Championship Game during its first two years of existence, was awarded a one-year extension to its two-year contract to host the game. The 2006 game suffered from poor attendance, resulting in over \$1 million in losses for the Gator Bowl Association. In the off-season, the Gator Bowl Association declared that if sales did not improve for the 2007 ACC Championship game, the game's Jacksonville future would be in jeopardy. Attendance for the 2006 game was low due to high travel costs stemming from Jacksonville's distance from the participating schools, and the 2007 participants—Boston College and Virginia Tech—faced the same problem.

With Jacksonville's future as host in doubt, representatives from Charlotte, North Carolina, Tampa, Florida, and Jacksonville visited the ACC offices to lobby to host the 2008 game. Orlando, Florida, which had been an early contender to host the 2008 game, was eliminated from consideration before the meetings took place. As kickoff drew closer, the Gator Bowl Association expressed displeasure with the poor ticket sales, saying nearly 20,000 tickets remained unsold as of the week of the game, and that if it was not a sellout the game would likely not remain in Jacksonville.

### Offensive matchups

Media attention was also directed at the teams' offensive capabilities. Boston College quarterback Matt Ryan was named the Atlantic Coast Conference Player of the Year in the week leading up to the game. In the first half of the 2007 season, Ryan had been prominently mentioned in candidate lists for the Heisman Trophy, college football's highest individual award. Although Ryan's late-game comeback in their previous game against Virginia Tech had made him a front-runner, the team's two subsequent losses to unranked teams dropped him from contention for the Heisman. Excellent performances in a division-clinching win at Clemson and against Miami seemed to return Ryan to Heisman-candidate form, however, and heading into the ACC Championship Game, Ryan appeared to be the biggest offensive threat for Boston College.

Virginia Tech's offense was led by an unusual two-quarterback system, as junior Sean Glennon shared time with freshman Tyrod Taylor. While Glennon proved to be a better pocket passer, Taylor's quickness enabled him to scramble out of trouble and gain positive yardage even when no open receivers were available for passes. Until the final game of the season, either Taylor or Glennon was hampered by injury and limited the two-quarterback system's effectiveness. Although the two-quarterback system proved effective against Virginia, there were still questions about how well such an unusual setup would work in the ACC Championship Game.

On the ground, Taylor's offensive scrambling, while effective, was not Virginia Tech's primary rushing weapon. Running back Brandon Ore, Virginia Tech's starter at the position, would need to have a good game, analysts predicted, if the Hokies wanted to win the game. Ore, who suffered several injuries during the 2006 season, failed to produce meaningful offensive yardage until late in the season, disappointing many fans who hoped he would repeat his excellent 2006 performance on the field. With a 146-yard performance against Virginia in the final game of the regular season, Ore seemed to have regained his 2006 form and promised success in the ACC Championship Game.

The Boston College ground offense was led by running back Andre Callender, who had perhaps his biggest game of the year during the division-clinching match against Clemson two weeks earlier. In that game, Callender finished with 92 receiving yards and 75 rushing yards. Due to the success of Matt Ryan's passing attack, however, Callender was used mostly as a backfield receiver and was the team's leading receiver statistically during the 2007 season. In the regular season, Callender amassed 905 yards rushing, 613 yards receiving, and 13 total touchdowns. Callender's normal backup, running back A.J. Brooks, was suspended for the ACC Championship Game.

### Defensive matchups

Virginia Tech's defense was considered stronger than that of Boston College. For the ACC Championship Game, Virginia Tech returned senior linebacker Vince Hall to the starting lineup. Hall had sat out four straight games, including the previous Boston College match, after suffering a broken forearm and wrist. ESPN named Hall and Xavier Adibi, Tech's other senior linebacker, the "best linebacker duo in the country".

On Virginia Tech's defensive secondary, Brandon Flowers, one of Tech's starting cornerbacks, was a second-team All-ACC defensive selection and had five interceptions in the season. Assisting Flowers would be Victor "Macho" Harris, who had also netted five interceptions during the regular season. During the 2007 season, Sports Illustrated called the two "maybe the finest cornerback duo in America."

At the end of the regular season, Boston College was ranked 26th nationally in total defense, and 2nd nationally in run defense. Its pass defense, however, was ranked 106th in the country, and since Boston College was without senior cornerback DeJuan Tribble, who was recovering from a sprained knee ligament, it was expected that the Eagles' linebackers would have to play a very good game to stop Virginia Tech's passing offense. Jo-Lonn Dunbar, who had been named to the preseason watch list for the Bronko Nagurski Trophy (awarded to the top defensive player in the country) was expected to fill the gaps and stop both rushing and passing elements of Virginia Tech's offense.

In addition, safety Jamie Silva would have to play a strong game to support the Boston College cornerback replacing the injured Tribble. Silva, an All-ACC defensive selection, led the team with five interceptions and was very good in moving up to stop the run as well. On the defensive line, defensive end Nick Larkin was a quarterfinalist for the Lott Trophy, an award given to the defensive player with the most "defensive impact" nationally.

## Game summary

The 2007 ACC Championship Game kicked off at 13:10 EST in Jacksonville, Florida. At kickoff, the weather was partly cloudy, with winds from the northeast at 18 miles per hour (29 km/h). The air temperature was 69 °F (21 °C). The official attendance estimate was 53,212, but by most accounts the actual attendance was far lower. Virginia Tech fans made up most of the crowd, and fewer than 5,000 Boston College fans were present at the game. The game was broadcast on ABC and netted a television rating of 4.1, placing it behind the SEC Championship Game and the Big 12 Championship Game, which earned ratings of 5.9 and 6.6, respectively.

The Marching Virginians, Virginia Tech's marching band, and the "Screaming Eagles", the Boston College Marching Band, played the national anthem before the game. The pre-game coin toss involved two members of the Wounded Warrior Project, a program that assists the physical rehabilitation of wounded American combat veterans returning to the United States from fighting overseas. One soldier from Virginia and another from Massachusetts were chosen to throw the ceremonial coin that would determine the game's starting possession. Supervising the coin toss was referee Jack Childress, who had also officiated the inaugural ACC Championship Game.

### First quarter

Virginia Tech won the opening coin toss and deferred its option to the second half. Boston College received the opening kickoff, which was downed in the end zone for a touchback. Starting at their own 20-yard line, the Eagles advanced down the field as quarterback Matt Ryan completed several passes and running back Andre Callender contributed several long runs. A pass interference call against Virginia Tech, coupled with a 10-yard run by Callender, put Boston College at the Virginia Tech 26-yard line. After three consecutive incomplete passes, Eagles kicker Steve Aponavicius attempted a 36-yard field goal. During the field goal, Virginia Tech special teams player Duane Brown broke through the Eagles' line and blocked the kick, giving Virginia Tech possession of the ball.

Virginia Tech's offense, led by quarterback Sean Glennon, began their first possession at their own 37-yard line. However, a sack, a tackle for loss, and an incomplete pass denied the Hokies' offense positive yardage and they were forced to punt. Tech punter Brent Bowden managed a 54-yard kick, which forced the Eagles to start at their own 14-yard line, but three big plays of 16, 19, and 19 yards drove the Eagles deep into Virginia Tech territory. As before, however, Virginia Tech's defense stiffened and Boston College was forced into a fourth down. Instead of attempting a long field goal, the Eagles instead attempted to convert the fourth down but were foiled by an incomplete pass.

On the Hokies' second offensive possession, quarterback Tyrod Taylor took the field in place of Sean Glennon. Two successful passes and two short runs resulted in two first downs and Virginia Tech advanced the ball across the 50-yard line and into Boston College territory. As Taylor attempted to scramble for yet another short run, however, he was tackled behind the line of scrimmage and fumbled the ball. The loose ball was scooped up by Boston College defender Jamie Silva, who returned it 51 yards for a touchdown. The touchdown and subsequent extra point were the first points of the game and gave Boston College a 7–0 lead with 4 minutes remaining in the quarter.

After the kickoff, Virginia Tech's offense again failed to advance the ball. After a three-and-out, the Hokies again punted. The ball traveled 44 yards, forcing the Eagles to start at their own 21-yard line. As the quarter came to a close, the Eagles drove the ball deep into Virginia Tech territory. At the end of the first quarter, Boston College led 7–0.

### Second quarter

At the beginning of the second quarter, the Hokies' defense began to stiffen. Aided by a 10-yard holding penalty against the Eagles, Matt Ryan was forced to complete a 14-yard pass on 4th-and-9 to earn a first down and keep the drive alive. Three incomplete passes followed, however, and the Eagles again settled for a field goal attempt. This time, the 37-yard kick sailed through the uprights, giving Boston College a 10–0 lead with 11:20 remaining in the first half.

Virginia Tech's first offensive drive of the second quarter began on an auspicious note as quarterback Sean Glennon completed a 16-yard pass to wide receiver Josh Morgan. Following the play, a Boston College player committed a personal foul, which added 15 yards to the end of the pass. Another long pass by Glennon, coupled with yet another Boston College penalty, put Virginia Tech deep into the red zone, and the Hokies scored on a 5-yard touchdown pass to Morgan. With 8:15 remaining in the first half, Virginia Tech narrowed Boston College's lead to just three points.

On the ensuing possession, Boston College needed only seven plays and just under three minutes to travel 74 yards. The drive culminated in a 14-yard quarterback scramble for a touchdown. Duane Brown, who had blocked the first Boston College field goal attempt, again charged through the Boston College offensive line and blocked the extra point attempt. This time, the ball bounced into the hands of Virginia Tech's Brandon Flowers, who returned it 75 yards for a defensive two-point conversion. The play kept Boston College's lead within a single touchdown and extra point. With 5:27 remaining in the half, the score was now 16–9 in favor of Boston College.

Tech quarterback Sean Glennon's first pass of the new possession, long throw downfield, was intercepted by Boston College defender Jamie Silva. The length of the pass meant Boston College did not have good field position following the turnover. After earning a quick first down, the Eagles were stopped and forced to punt. With 2:13 remaining before halftime, the Hokies had one more offensive opportunity.

Beginning at their own 20-yard line, the Virginia Tech offense marched down the field. Running back Branden Ore ran 11 yards for a first down, and two long passes from Sean Glennon to wide receiver Eddie Royal put the Hokies into scoring position. After failing to gain first downs with short runs, Virginia Tech was forced to use its timeouts to stop the clock and the first half from ending before they had a chance to score. On a 3rd-and-7 from the Boston College 13-yard line, Glennon finally connected with wide receiver Josh Hyman, who crossed into the end zone for a touchdown. The extra point tied the game, 16–16.

With no time left to mount an answering drive, Boston College received the kickoff and let time run out. Heading into halftime, the two teams were tied, 16–16.

### Third quarter

Because they deferred their selection to the second half during the opening coin toss, Virginia Tech received the ball to begin the half. The Hokies continued to rotate between quarterbacks Sean Glennon and Tyrod Taylor during the possession, and picked up two first downs, one through the air and the other on the ground. After Glennon was sacked at the 50-yard line, however, the drive sputtered and the Hokies were forced to punt the ball.

Boston College, in their first possession of the second half, fared even worse than Virginia Tech did. Two incomplete passes and a 5-yard delay of game penalty forced Boston College into a three-and-out possession that resulted in a punt. On its second possession, Virginia Tech had a three-and-out drive, thanks in part to an 11-yard sack of Sean Glennon by Boston College's Kevin Atkins.

After receiving the punt, Boston College quarterback Matt Ryan connected on a 31-yard pass to wide receiver Brandon Robinson. As before, however, the offense stalled. On 4th-and-1 from the Virginia Tech 30-yard line, Ryan attempted a pass that fell incomplete, turning the ball over on downs. As a result of pressure applied by the Boston College defense, the Hokies continued to have difficulty moving the ball.

The Hokies were forced to punt again, and Brent Bowden's 50-yard punt stuck the Eagles deep in their own territory. The drive began with a five-yard penalty against Boston College and culminated two plays later in a six-yard loss on a sack of Matt Ryan by Hokie defender Barry Booker. Boston College punted, but the kick by Johnny Ayers traveled just 34 yards before sailing out of bounds.

Virginia Tech had good starting field position at their own 44-yard line. One quick first down later, the clock ran out on the third quarter. As neither team had scored in the quarter, the score remained tied at 16–16.

### Fourth quarter

Despite starting almost at midfield, the offensive drive that began at the end of the third quarter failed to reach field goal range, and the Hokies were forced to punt. Boston College's offense fared no better, however, and punted after a three-and-out possession. The ball was downed at the Virginia Tech 16-yard line, and the Hokies began their first full offensive possession of the fourth quarter.

After an incomplete pass from quarterback Tyrod Taylor, the Hokies got their first big offensive break of the second half. On a designed play, Taylor scrambled for 31 yards, the largest play in the game for the Hokies. Two successful runs by running back Branden Ore followed, earning the Hokies 23 more yards and pushing the offense deep into Boston College territory. A false-start penalty set the Hokie offense back, but on the next play, quarterback Sean Glennon connected with wide receiver Eddie Royal on a 24-yard strike for a touchdown. The touchdown and extra point were the first points of the second half and gave Virginia Tech a 23–16 lead with 6:30 remaining in the game.

Boston College began its second possession of the fourth quarter knowing it had to score a touchdown to tie the game. Quarterback Matt Ryan had his best success of the day, connecting on seven of ten passes during the drive and picking up 58 yards. All the Eagles' yardage on the drive came through the air, and with 2:25 remaining, the Eagles found themselves at the Virginia Tech 14-yard line. Facing a fourth down and needing four yards for a first down, Matt Ryan fell back to attempt a pass. The throw was intercepted by Virginia Tech's Vince Hall.

Starting at its own 10-yard line, Virginia Tech ran three straight running plays in an effort to run the clock down and prevent Boston College from having enough time to conduct another offensive drive. After the third run was stopped for no gain, however, the Hokies were forced to punt the ball. Boston College now had 28 seconds to score a touchdown and either tie the game with an extra point or win it with a two-point conversion.

The Boston College drive began on its own 35-yard line. With little time remaining, Boston College would have to complete one or more Hail Mary passes. Although the odds of completing one such pass, let alone several, were very low, many Virginia Tech fans remained worried, as Boston College had previously beaten the Hokies in similar circumstances earlier in the season. Matt Ryan's first two passes fell incomplete, and his third was intercepted by Virginia Tech's Xavier Adibi and returned 40 yards for a Virginia Tech touchdown.

The score came with 11 seconds remaining and gave Virginia Tech its final lead, 30–16. With no chance to win, Boston College elected to let the clock run out after receiving the kickoff. Virginia Tech won the 2007 ACC Championship, 30–16.

## Final statistics

Virginia Tech quarterback Sean Glennon was named the game's Most Valuable Player. Glennon finished the game having completed 18 of his 27 passes, earning 174 passing yards, three touchdowns (18 points), and one interception. Boston College quarterback Matt Ryan had finished 33 of 52 for 305 yards and two interceptions, no passing touchdowns, and one rushing touchdown.

Each team finished with two turnovers—Virginia Tech fumbled the ball once and threw one interception, while Boston College's offense threw two. Each team earned seven points off of turnovers, and Virginia Tech blocked two kicks. The two blocked kicks effectively netted five points for Virginia Tech, as the blocked field goal prevented Boston College from scoring three points, and the other blocked kick was returned 75 yards for a rare defensive two-point conversion. The two blocked kicks by Virginia Tech were the first and second blocked kicks in ACC Championship Game history, and Boston College's fumble return for a touchdown was the first fumble recovery and defensive touchdown in ACC Championship Game history.

### Virginia Tech statistical recap

Two-thirds of Virginia Tech's 300 total offensive yardage came via passes from quarterbacks Sean Glennon (174 yards) and Tyrod Taylor (28 yards). Glennon's three passing touchdowns tied an ACC Championship Game record set by former Virginia Tech quarterback Marcus Vick in 2005. Glennon also set the ACC Championship Game record for pass completion percentage (66.7%) by completing 18 of his 27 passes. Taylor, meanwhile, set ACC Championship Game records for longest run and longest quarterback run with a 31-yard scramble in the second quarter that helped set up the tying touchdown for Virginia Tech. Taylor finished the game with 36 rushing yards, the third-most of any player in the game.

On the ground, Taylor's performance was supplemented by Tech running back Branden Ore, who led all rushers with 55 yards on 19 rushes. Fourteen of Ore's 55 yards came on a single play halfway through the fourth quarter when the Boston College's defensive line gave way, admitting Tech's runner into the defensive secondary. The run helped set up Virginia Tech's go-ahead touchdown later in the fourth quarter. Capping Tech's ground game were complementary performances by Kenny Lewis and Sean Glennon, each of whom earned fewer than 10 yards, but picked up first downs on two plays.

Leading all Tech receivers was Josh Morgan, who caught eight passes for 55 yards and a touchdown. Eddie Royal also had an excellent game for the Hokies, catching two long passes of 18 yards and 11 yards on subsequent plays in the second quarter. Royal's 2 catches drove the Hokies deep into Boston College territory, setting up a 13-yard touchdown pass to Josh Hyman that tied the game at halftime. Royal's biggest play, however, came halfway through the fourth quarter when he caught the go-ahead touchdown pass from Sean Glennon. The 24-yard reception was Royal's longest catch of the day, and the touchdown gave the Hokies a lead they would not relinquish for the rest of the game.

Though its offense performed well, it was Virginia Tech's special teams and defense that earned it the win. Duane Brown's twin blocked kicks were the first blocks recorded in ACC Championship Game history and were the 116th and 117th blocked kicks recorded at Virginia Tech under head coach Frank Beamer. In addition to the blocks, Tech special teams excelled on punts and kickoffs. Tech punter Brent Bowden finished the day with seven punts for a total of 324 yards. A 54-yard kick in the first quarter was the fourth-longest punt in ACC Championship Game history.

On defense, linebacker Vince Hall, in his second game after recovering from a broken forearm, led all defensive players with 11 tackles. Hall also recorded an interception in the late stages of the fourth quarter that allowed Virginia Tech to run down the clock and force Boston College into a hasty offense. Tied for third overall was Tech's Xavier Adibi, who recorded nine tackles (one for loss) and caught the game-ending interception. Adibi returned the interception 40 yards for a defensive touchdown that sealed the victory for the Hokies.

### Boston College statistical recap

Though Boston College lost the game on the scoreboard, it won almost every statistical category. Quarterback Matt Ryan outperformed both Hokie quarterbacks combined in passing yardage, throwing for 305 yards. Ryan was extremely accurate through the air in the fourth quarter, throwing eight straight complete passes, an ACC Championship Game record. Ryan also was surprisingly successful on the ground, rushing for Boston College's touchdown of the game—a 14-yard sprint in the second quarter that put Boston College ahead 16–7.

In the first half, the Eagles offense recorded 20 first downs. In the second half, it managed just four first downs, three of which came in one drive in the fourth quarter. As a result of second-half pressure from Virginia Tech, Ryan was forced into two late-game interceptions, including one that was returned for a Virginia Tech defensive touchdown.

Ryan finished the game with 35 rushing yards, just one short of Hokie quarterback Tyrod Taylor, who had been highly promoted as a runner heading into the game. Ryan finished fourth among all rushers, and Eagle running back Andre Callender, the sole running back on the Eagles' roster, finished second, rushing for 51 yards in the game. Callender game-long 11-yard run helped set up the Eagles for a field goal attempt early in the second quarter.

Callender's true success, however, was in the passing game, where he accrued 92 yards, putting him first among all receivers in the game. Callender's 13 catches were an ACC Championship Game record and were the fourth-highest total for a receiver in any game in ACC history. Wide receiver Kevin Challenger finished the game with 4 catches for 45 yards, while the Eagles' Rich Gunnell finished the game with 54 yards. Surprisingly for the number of receiving yards recorded by the Eagles in the game, no Boston College receiver caught a touchdown.

Boston College punter Johnny Ayres kicked four punts a total of 159 yards, including one long kick that traveled 55 yards and set the mark for the third-longest punt in ACC Championship Game history. Kicker Steve Aponavicius successfully kicked a 37-yard field goal early in the second quarter. but after his second kick was blocked, Boston College head coach Jeff Jagodzinski seemed reluctant to try long field goals and instead sent in the offense to attempt to convert the fourth down. Out of four tries, only one fourth down was converted.

On defense, Boston College had more success than predicted by pre-game coverage. Jamie Silva's fumble return for a touchdown was the first defensive score in ACC Championship Game history. Silva finished the game with five tackles (one for loss), one interception, the forced fumble, and the defensive touchdown. DeLeon Gause, meanwhile, was the Eagles' leading tackler, recording 10 stops including one tackle for loss. Altogether, the Eagles recorded four sacks and nine tackles for loss, holding the Hokie offense in check for most of the game.

## Post-game effects

Virginia Tech's victory in the ACC Championship Game had far-reaching sporting consequences for the 2007–2008 college football bowl season and in the future site of the ACC Championship Game. The 2007 game injected approximately \$10 million into the Jacksonville economy. Thousands of hotel rooms were filled by fans traveling to the game, and the impact they created was larger than that of the previous year's game, which featured teams that had shorter distances to travel and whose fans had generated less demand for overnight accommodation.

### 2008 ACC Championship Game

After poor attendance in the ACC Championship Game at Jacksonville for the second straight year, ACC officials and representatives of the conference's member schools elected not to extend the Gator Bowl Association's contract to host the game. On December 12, the ACC announced that Tampa, Florida would host the game in 2008 and 2009 and Charlotte, North Carolina would host the game in 2010 and 2011.

The cities were chosen based on bids presented to the ACC and its member schools. Each city requested and was granted a two-year contract, locking the ACC into the locations well in advance of the actual games. Tampa was chosen as the site of the 2008 game because Charlotte was scheduled to hold the annual convention of the Association for Career and Technical Education at the same time as the game, and adequate hotel space would not be ready in time for the two events.

### Bowl effects

With its win, Virginia Tech clinched an automatic bid to the 2008 Orange Bowl. This caused ripple effects in the bowl destinations for virtually every bowl-eligible ACC team. In the 2007 season, the ACC had guaranteed tie-ins with eight bowl games.

The ACC's representatives to these bowls were picked in a hierarchical system that allowed the Chick-fil-A Bowl to have the first selection after the Orange Bowl's automatic pick of the winner of the ACC Championship Game. Following the Chick-fil-A Bowl were the Gator Bowl, Champs Sports Bowl, Music City Bowl, Meineke Car Care Bowl, Emerald Bowl, and Humanitarian Bowl, in that order. The ACC's agreement with the bowls dictated that the bowls would select the highest-ranking ACC team left after the bowls with higher selections made their pick. Bowls would be allowed to skip the highest remaining team only if the next team was within one conference win of the highest remaining team. Therefore, a bowl could select a 5–3 team over a 6–2 team, but could not select a 4–4 team over a 6–2 team.

With Virginia Tech earning an automatic bid to the Orange Bowl, the Chick-fil-A Bowl had the first pick of the remaining ACC teams. Boston College, by virtue of its loss in the ACC Championship Game, was the highest remaining team, but Chick-fil-A Bowl representatives instead chose to invite Clemson, which had finished behind Boston College in the Atlantic Division standings. In making their decision, Chick-fil-A Bowl representatives cited Boston College's poor attendance at the ACC Championship Game in Jacksonville. The Gator Bowl, which is also held in Jacksonville, was reluctant to choose a team that had participated in the ACC Championship Game out of fear that the team's fans would be unwilling to return to Jacksonville so quickly. The Gator Bowl Association requested and received a waiver from the league's strict bowl selection rules and selected Virginia over Boston College.

The Champs Sports Bowl was thus forced to select Boston College. Boston College players and fans, owing to the decreased status of the Champs Sports Bowl when compared with the Orange, Chick-fil-A, and Gator Bowls, were disappointed with the selection and match against Michigan State. Had Boston College won the ACC Championship Game, it would have earned the automatic bid to the Orange Bowl, and Virginia Tech would have been selected by the Chick-fil-A Bowl, which had earlier expressed an interest in inviting the Hokies to the game for a second straight year. Clemson would have been bumped down to the Gator Bowl, and Virginia would have been forced into the Champs Sports Bowl.

## See also

- List of Atlantic Coast Conference football champions
- Boston College–Virginia Tech football rivalry

Other conference championship games

- 2007 SEC Championship Game
- 2007 Big 12 Championship Game
- 2007 MAC Championship Game
- 2007 Conference USA Football Championship Game

2007 Atlantic Coast Conference football season

December 2007 sports events in the United States