Ophiostoma novo-ulmi

Ophiostoma novo-ulmi
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Sordariomycetes
Order:	Ophiostomatales
Family:	Ophiostomataceae
Genus:	Ophiostoma
Species:	O. novo-ulmi
Binomial name
	Ophiostoma novo-ulmi; Brasier

Last updated October 10, 2023

Ophiostoma novo-ulmi is a species of fungus in the family Ophiostomataceae. It is one of the key causative agents associated with Dutch Elm Disease (DED),^[1] along with Ophiostoma ulmi and Ophiostoma himal-ulmi .

Dutch Elm Disease was first identified in Europe during the early 1900s and by the 1940s the disease had spread throughout Europe and into the United States and Canada.^[2] Elm trees (Ulmus) were heavily used as a trade commodity in logging practices in the late 1800s-1900s. Historically, these trees have seen widespread use as a building material in products such as wheels, chairs, ships, and coffins.^[3] Wood from Ulmus trees has been favored for building due to the trees' ability to withstand prolonged exposure to water without rotting. The adaptability of this tree along with its multitude of applications for building opened up its demand in trading.^{[ citation needed ]}

It has been determined that Ophiostoma ulmi and Ophiostoma novo-ulmi have evolved separately from each other in different regions of the world though it has been thought that novo-ulmi has obtained genes from Ophiostoma ulmi making it a more effective pathogen for Elm trees.^{[ citation needed ]}

O. ulmi caused one of the first pandemics of the species, within Europe and North America, between 1910-1940 and caused 10-40% death of genus Ulmus. This pandemic was followed by a second pandemic beginning in the 1940s caused by the O. novo-ulmi species. This pathogen proved to be more invasive and aggressive in comparison to other species associated with the disease. The introduction of O. novo-ulmi is traced back to the logging trade among regions. Logs infected with the pathogen and traded throughout Europe and intercontinentally leading to the spread of the fungus. O. novo-ulmi came in contact with various amounts of highly susceptible host species in Europe, western Asia and North America making it easier to spread Dutch Elm Disease. Bark beetles have become a vector for the fungus to spread among elm tree groves. The bark beetles often carry spores on their bodies. The spores are easily transferred via twig crotches where they obstruct vessels by gums, tyloses, fungal material and foliage wilts, causing the tree to die.^[1] These beetles complete an entire life cycle in one elm tree until the tree can no longer support the beetles. Following this young beetles will find healthy trees to inhabit which they infect with spores they carry from the previous elm tree. When the beetles feed on the tree they introduce the fungi to the food and water supply of the tree via the branches connecting to the xylem of the tree, allowing rapid spread throughout the vascular tissue of the tree.^[4]

Once the fungus has been introduced to the vascular tissue of the tree it spreads rapidly, causing death as a result of the tree's natural immune response. In the xylem vessels the fungus produces yeast-like spores and multicellular filamentous hyphae. This allows for vertical movement in the vessels, then moves laterally to infect neighboring vessels.^[4] Logs that contain both the fungi and beetles can transmit the pathogen to native species at much higher rate and cause a greater range for invasion. Furthermore, O. novo-ulmi can also spread from infected trees to healthy trees through root grafts. When the roots of adjacent elm trees come into contact with each other underground, the fungus can move from the infected tree to the healthy tree through these root connections.^[2] It can also invade an elm tree through wounds on the bark or branches. This can occur naturally through storms, animal activity, or human interventions such as pruning or other tree care practices. The spores of the fungus can enter the tree through these wounds and establish an infection.^[2] Once inside the tree, O. novo-ulmi grows in the water-conducting vessels of the tree, blocking the flow of water and nutrients, which eventually leads to wilting, yellowing of leaves, and tree death.^[2] The fungus also produces toxic compounds that further contribute to the damage to the tree's vascular system and overall health.

O. novo-ulmi infestation can spread rapidly, causing severe damage and death to susceptible elm trees. Effective management strategies, such as tree removal, pruning, and applications, may be used to control the spread of the disease in affected areas.^[4] Early detection and prevention are key in managing Dutch elm disease caused by O. novo-ulmi.

Related Research Articles

Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of North America and Eurasia, presently ranging southward in the Middle East to Lebanon and Israel, and across the Equator in the Far East into Indonesia.

Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Believed to be originally native to Asia, the disease was accidentally introduced into America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not have resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Bea Schwarz and Christine Buisman, who both worked with professor Johanna Westerdijk. The disease affects species in the genera Ulmus and Zelkova, therefore it is not specific to the Dutch elm hybrid.

Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. This disease has been investigated extensively since the early years of this century. The pathogen that causes Fusarium wilt is Fusarium oxysporum. The species is further divided into formae speciales based on host plant.

<span class="mw-page-title-main">Bark beetle</span> Subfamily of beetles

A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.

Oak wilt is a fungal disease caused by the organism Bretziella fagacearum that threatens Quercus spp. The disease is limited to the eastern half of the United States; first described in the 1940s in the Upper Mississippi River Valley. The pathogen penetrates xylem tissue, preventing water transport and causing disease symptoms. Symptoms generally consist of leaf discoloration, wilt, defoliation, and death. The disease is dispersed by insect vectors and to adjacent trees through underground root networks. However, human spread is the most consequential dispersal method. Moving firewood long distances can potentially transport diseases and invasive species.

Ulmus × hollandica 'Commelin' is a Dutch hybrid cultivar released for sale in 1960. The tree was raised at Baarn as clone 274 by the Foundation Willie Commelin Scholten Phytopathological Laboratory in 1940, from a crossing of Ulmus × hollandica 'Vegeta' and clone 1, an Ulmus minor selected from a 1929 elm seedlings lot obtained from the Barbier nursery, Orléans.

Ulmus 'Sapporo Autumn Gold' is one of the most commercially successful hybrid elm cultivars ever marketed, widely planted across North America and western Europe, although it has now been largely supplanted by more recent introductions. Arising from a chance crossing of the Japanese elm and Siberian elm, seed was sent in 1958 by Prof. Nobuku Takahashi and his colleagues at the Sapporo Botanical Garden of Hokkaido University, Sapporo, to Eugene Smalley at the University of Wisconsin–Madison. The patent issued in 1975 has expired, and there are now no propagation restrictions.

Ophiognomonia clavigignenti-juglandacearum is a mitosporic fungus that causes the butternut canker, a lethal disease of butternut trees. It is also known to parasitize other members of the genus Juglans on occasion, and very rarely other related trees including hickories. The fungus is found throughout North America, occurring on up to 91% of butternut trees, and may be threatening the viability of butternut as a species.

Ophiostoma ulmi is a species of fungus in the family Ophiostomataceae. It is one of the causative agents of Dutch elm disease. It was first described under the name Graphium ulmi, and later transferred to the genus Ophiostoma.

Leptosphaeria coniothyrium is a plant pathogen. It can be found around the world.

Nectria cinnabarina, also known as coral spot, is a plant pathogen that causes cankers on broadleaf trees. This disease is polycyclic and infects trees in the cool temperate regions of the Northern Hemisphere. N. cinnabarina is typically saprophytic, but will act as a weak parasite if presented with an opportunity via wounds in the tree or other stressors that weaken the tree's defense to the disease. A study published in 2011 showed that this complex consists of at least 4 distinct species. There are only a few ways to manage this disease with techniques such as sanitation and pruning away branches that have the cankers. N. cinnabarina is not as significant a problem as other Nectria spp., some of which are the most important pathogens to infect hardwood trees.

Ulmus wallichiana subsp. wallichiana was identified by Melville and Heybroek after the latter's expedition to the Himalaya in 1960.

Ulmus wallichiana var. tomentosa was identified by Melville & Heybroek after the latter's expedition to the Himalaya in 1960.

A wilt disease is any number of diseases that affect the vascular system of plants. Attacks by fungi, bacteria, and nematodes can cause rapid killing of plants, large tree branches or even entire trees.

Scolytus multistriatus, the European elm bark beetle or smaller European elm bark beetle, is a bark beetle species in the genus Scolytus. In Europe, while S. multistriatus acts as vector of the Dutch elm disease, caused by the Ascomycota Ophiostoma ulmi, it is much less effective than the large elm bark beetle, S. scolytus.

Ophiostoma himal-ulmi is a species of fungus in the family Ophiostomataceae. It is one of the causative agents of Dutch elm disease. It was first isolated around breeding galleries of scolytid beetles in the bark of Ulmus wallichiana. This, together with the fact that it is endemic to the Himalayas, is the reason it is named himal-ulmi.

The foamy bark canker is a disease affecting oak trees in California caused by the fungus Geosmithia sp. #41 and spread by the Western oak bark beetle. This disease is only seen through the symbiosis of the bark beetles and the fungal pathogen. The bark beetles target oak trees and bore holes through the peridermal tissues, making tunnels within the phloem. The fungal spores are brought into these tunnels by the beetles and begin to colonize the damaged cells inside the tunnels. Symptoms of the developing fungus include wet discoloration seeping from the beetle entry holes as the fungus begins to consume phloem and likely other tissues. If bark is removed, necrosis of the phloem can be observed surrounding the entry hole(s). As the disease progresses, a reddish sap and foamy liquid oozes from entry holes, thus giving the disease the name foamy bark canker. Eventually, after the disease has progressed, the tree dies. This disease is important because of its detrimental effects on oak trees and its ability to spread to several new Californian counties in just a couple of years.

Hypoxylon canker of shade trees is a weak ascomycete fungus that negatively affects growth and can eventually lead to the death of already dying or diseased host trees. There are many different species that affect different trees. For example, Hypoxylon atropunctatum, a common species, is found on oak trees, Hypoxylon tinctor affects sycamore trees, and Hypoxylon mammatum infests aspen trees.

Ulmus of King & Co nursery, Rayne, are elms grown from cuttings taken in the early 1990s from two to four old trees surviving in north Essex, England, amidst others afflicted by Dutch elm disease (DED). Photographs of the first source tree, near Braintree, appeared in the press in 2010. The second source tree is known locally as the Lynfields Elm, near Witham. Released in 2010, the saplings are described by the nursery that marketed them as "English elm". A 2010 genetic test referred to them as "English Elm ", an identification presumably supplied by the nursery itself. At Kew, however, three King & Co elms are listed as U. minorMill., without a cultivar name. The 2010 genetic test found the source trees sampled to be of different genotypes.

Scolytus schevyrewi, the banded elm bark beetle, is a 3–4 mm long elm bark beetle species in the genus Scolytus native from Asia and accidentally introduced to North America. It is a vector of the Dutch elm disease, caused by the Ascomycota Ophiostoma ulmi and Ophiostoma novo-ulmi. In North America, it is displacing both the native elm bark beetle and the previously introduced smaller European elm bark beetle, which are becoming less common in their range with the expansion of S. schevyrewi.

References

1 2 "Ophiostoma Novo-Ulmi - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2023-04-19.
1 2 3 4 Hubbes, M. (1999-04-01). "The American elm and Dutch elm disease". The Forestry Chronicle. 75 (2): 265–273. doi: 10.5558/tfc75265-2 . ISSN 0015-7546.
↑ "The importance of, and threat to, elm trees". www.biosphere.im. Retrieved 2023-04-19.
1 2 3 Comeau, André M.; Dufour, Josée; Bouvet, Guillaume F.; Jacobi, Volker; Nigg, Martha; Henrissat, Bernard; Laroche, Jérôme; Levesque, Roger C.; Bernier, Louis (2014-12-24). "Functional Annotation of the Ophiostoma novo-ulmi Genome: Insights into the Phytopathogenicity of the Fungal Agent of Dutch Elm Disease". Genome Biology and Evolution. 7 (2): 410–430. doi:10.1093/gbe/evu281. ISSN 1759-6653. PMC 4350166 . PMID 25539722.

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[:0-1] 1 2 "Ophiostoma Novo-Ulmi - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2023-04-19.

[:1-2] 1 2 3 4 Hubbes, M. (1999-04-01). "The American elm and Dutch elm disease". The Forestry Chronicle. 75 (2): 265–273. doi: 10.5558/tfc75265-2 . ISSN 0015-7546.

[3] "The importance of, and threat to, elm trees". www.biosphere.im. Retrieved 2023-04-19.

[:2-4] 1 2 3 Comeau, André M.; Dufour, Josée; Bouvet, Guillaume F.; Jacobi, Volker; Nigg, Martha; Henrissat, Bernard; Laroche, Jérôme; Levesque, Roger C.; Bernier, Louis (2014-12-24). "Functional Annotation of the Ophiostoma novo-ulmi Genome: Insights into the Phytopathogenicity of the Fungal Agent of Dutch Elm Disease". Genome Biology and Evolution. 7 (2): 410–430. doi:10.1093/gbe/evu281. ISSN 1759-6653. PMC 4350166 . PMID 25539722.

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