Magnaporthe rhizophila

Last updated

Magnaporthe rhizophila
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Sordariomycetes
Order: Magnaporthales
Family: Magnaporthaceae
Genus: Magnaporthe
Species:
M. rhizophila
Binomial name
Magnaporthe rhizophila
D.B. Scott & Deacon
Magnaporthe rhizophila
Information icon.svg
NA cap icon.svg Hymenium attachment is not applicable
NA cap icon.svgLacks a stipe
Transparent spore print icon.svg
Spore print is black
Mycomorphbox Question.pngEdibility is unknown

Magnaporthe rhizophila is a fungus species in the family Magnaporthaceae. These dark mycelial fungi are common pathogens of cereal and grass roots. [1] [2] Rice blast is one disease known to be caused by M. rhizophila and presents with vascular discoloration in the host organism. [3] The fungus lives best in drier humid conditions, explaining why it is most often found in the soils of Australia, South Africa, and the Southeastern United States. [2]

Contents

Development

Similar to other ascomycota, the lifecycle of M. rhizophila is split into two parts: the sexual and asexual stages. [3] The sexual lifestage is characterized by a globose (400-500 um wide) [1] fruit-like body that contains the sexual spores, called a perithecia, which occurs in either singles or multiples. Perithecia are flask-like shaped and contain asci, which are septated, unitunicate stalks of 8 ascospores. The ascospores are biseriate, fusiform, and slightly curved or helical when naive. [1] The perithecia is lined with cells called the peridium and has accessory structures called periphyses and paraphyses that surround the outside and inside of the structure, respectively. Paraphyses inside the perithecia dissolve once asci reach maturity. The asexual lifestage is characterized by asexual conidial structures (6-20x2-6 um). Conidiophores are either simple or branched. [1] [4]
Compared to the fruiting bodies of other Magnaporthe species, rhizophila is considered faster growing (0.8 cm/d at 28 °C) [4] with slightly longer and wider conidial cells.
M. rhizophila is homothallic, so it is self-fertile and can mate with similar mating types within its own mycelia. [5]

Ecology

Magnaporthe rhizophila is considered a necrotrophic parasite [5] because it relies on the nutrients and support of other organisms to thrive. It is a heterotroph since it is unequipped to sequester energy on its own, hence its symbiotic behavior. Magnaporthacaea are family-specific soil-borne parasites of Gramineae; rhizophila specifically colonizes the roots of millet. [6]
Spores from M. rhizophila are dispersed by natural manners such as wind, water, and animals. These spores then settle in soil where they grow and mature through asexual life cycles until it is optimal for the hyphae to resume a sexual cycle and a host organism is near. Rhizophila is only root-infecting; however many of its Magnaporthe relatives are both soil and aerial-infecting. [7] The fungus has an appressorium [5] structure which functions to elicit effector hormones to increase host susceptibility (2 clade-specific types of small specific proteins (SSP) [8] ). Lignitubers have been considered a response by host cells after infection as a response to fungal invasion. [9] However, rhizophila kills host cells in 5–6 weeks. [1]
M. rhizophila has darkly pigmented hyphae, composing mycelia that has a gray-brown color, darker than species in the rest of its family. [4] It is able to be cultured in vitro and survives on PDA (potato dextrose agar) plates.

Geographical distribution

Magnaporthe rhizophila does not necessarily require much water to survive, localizing in drier humid regions of Australia, South Africa, and the Southeastern United States. [2]

Genetics

From data derived from genetic testing, it was found that M. rhizophila originated in South Africa. Fungal fossils demonstrated that the phyla diverged 31 million years ago from other Sordariomycetes, and the phylogeny diverged 21 million years ago from pezizomycotina. [9] [6]
Magnaporthe species are grouped into three divergent clades; [5] rhizophila is in clade classification D along with M. poae and G. incrustans. Rhizophila belongs to the Magnaporthe family based on its ascospore morphology; however, it has been considered for the Gaeumannomyces because they also produce phialophora-like anamorphs instead of sympodial pyricularia. [7] M. rhizophila is the only known Magnaporthe species with a phialophora anamorph. [10] Given these similarities between families, M. rhizophila is highly hybridized with other species among these groups. [10]
The M. rhizophila genome is composed of 5.8% transposable elements, lower than other species in its family. [8]

Related Research Articles

<span class="mw-page-title-main">Ascomycota</span> Division or phylum of fungi

Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.

<i>Ophiocordyceps sinensis</i> Species of fungus

Ophiocordyceps sinensis, known colloquially as caterpillar fungus, is an entomopathogenic fungus in the family Ophiocordycipitaceae. It is mainly found in the meadows above 3,500 metres (11,500 ft) on the Tibetan Plateau in Tibet and the Himalayan regions of Bhutan, India, and Nepal. It parasitizes larvae of ghost moths and produces a fruiting body which is valued in traditional Chinese medicine as an aphrodisiac. Caterpillar fungus contains the compound cordycepin, an adenosine derivative. However, the fruiting bodies harvested in nature usually contain high amounts of arsenic and other heavy metals, so they are potentially toxic and sales have been strictly regulated by China's State Administration for Market Regulation since 2016.

<i>Sordaria fimicola</i> Species of fungus

Sordaria fimicola is a species of microscopic fungus. It is commonly found in the feces of herbivores. Sordaria fimicola is often used in introductory biology and mycology labs because it is easy to grow on nutrient agar in dish cultures. The genus Sordaria, closely related to Neurospora and Podospora, is a member of the large class Sordariomycetes, or flask-fungi. The natural habitat of the three species of Sordaria that have been the principal subjects in genetic studies is dung of herbivorous animals. The species S. fimicola is common and worldwide in distribution. The species of Sordaria are similar morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination.

Heterothallic species have sexes that reside in different individuals. The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable of sexual reproduction from a single organism.

<span class="mw-page-title-main">Erysiphales</span> Order of fungi

Erysiphales are an order of ascomycete fungi. The order contains one family, Erysiphaceae. Many of them cause plant diseases called powdery mildew.

<i>Ceratocystis fimbriata</i> Species of fungus

Ceratocystis fimbriata is a fungus and a plant pathogen, attacking such diverse plants as the sweet potato and the tapping panels of the Para rubber tree. It is a diverse species that attacks a wide variety of annual and perennial plants. There are several host-specialized strains, some of which, such as Ceratocystis platani that attacks plane trees, are now described as distinct species.

<i>Gibberella zeae</i> Species of fungus

Gibberella zeae, also known by the name of its anamorph Fusarium graminearum, is a fungal plant pathogen which causes fusarium head blight (FHB), a devastating disease on wheat and barley. The pathogen is responsible for billions of dollars in economic losses worldwide each year. Infection causes shifts in the amino acid composition of wheat, resulting in shriveled kernels and contaminating the remaining grain with mycotoxins, mainly deoxynivalenol (DON), which inhibits protein biosynthesis; and zearalenone, an estrogenic mycotoxin. These toxins cause vomiting, liver damage, and reproductive defects in livestock, and are harmful to humans through contaminated food. Despite great efforts to find resistance genes against F. graminearum, no completely resistant variety is currently available. Research on the biology of F. graminearum is directed towards gaining insight into more details about the infection process and reveal weak spots in the life cycle of this pathogen to develop fungicides that can protect wheat from scab infection.

Eutypella canker is a plant disease caused by the fungal pathogen Eutypella parasitica. This disease is capable of infecting many species of maple trees and produces a large, distinguishable canker on the main trunk of the tree. Infection and spread of the disease is accomplished with the release of ascospores from perithecia. Therefore, the best way to manage the Eutypella canker is to remove trees that have been infected. If infected, it can decrease the quality of wood cut for lumber and can thus have a negative economic impact.

Monilinia fructigena is a plant pathogen in the fungus kingdom causing a fruit rot of apples, pears, plums, peaches and cherries.

<span class="mw-page-title-main">Fungus</span> Biological kingdom, separate from plants and animals

A fungus 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 one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.

<span class="mw-page-title-main">Orbiliaceae</span> Family of fungi

The Orbiliaceae are a family of saprobic sac fungi. It is the only family in the monotypic class Orbiliomycetes and the monotypic order Orbiliales. The family was first described by John Axel Nannfeldt in 1932 and now contains 288 species in 12 genera. Members of this family have a widespread distribution, but are more prevalent in temperate regions. Some species in the Orbiliaceae are carnivorous fungi, and have evolved a number of specialized mechanisms to trap nematodes.

<i>Helicobasidium</i> Genus of fungi


Helicobasidium is a genus of fungi in the subdivision Pucciniomycotina. Basidiocarps are corticioid (patch-forming) and are typically violet to purple. Microscopically they have auricularioid basidia. Asexual anamorphs, formerly referred to the genus Thanatophytum, produce sclerotia. Conidia-bearing anamorphs are parasitic on rust fungi and are currently still referred to the genus Tuberculina.

<span class="mw-page-title-main">Magnaporthaceae</span> Family of fungi

The Magnaporthaceae are a family of fungi in the order Magnaporthales. It was circumscribed by Paul F. Cannon in 1994 for a group of grass-associated fungi centered on Magnaporthe (Nakataea). Magnaporthaceae have a harpophora-like asexual morphology and are often associated with roots of grasses or cereals.

Magnaporthiopsis is a genus of ascomycete fungi. It has three species.

<span class="mw-page-title-main">Hypoxylon canker of shade trees</span> Tree disease

Hypoxylon canker of shade trees is a weak ascomycete fungus that negatively affects growth and can eventually lead to the death of weak 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.

<span class="mw-page-title-main">Pyriculariaceae</span> Family of fungi

The Pyriculariaceae are a family of ascomycete fungi in the order Magnaporthales. It was introduced by S. Klaubauf, M.H. Lebrun & P.W. Crous in 2014.

Microascus manginii is a filamentous fungal species in the genus Microascus. It produces both sexual (teleomorph) and asexual (anamorph) reproductive stages known as M. manginii and Scopulariopsis candida, respectively. Several synonyms appear in the literature because of taxonomic revisions and re-isolation of the species by different researchers. M. manginii is saprotrophic and commonly inhabits soil, indoor environments and decaying plant material. It is distinguishable from closely related species by its light colored and heart-shaped ascospores used for sexual reproduction. Scopulariopsis candida has been identified as the cause of some invasive infections, often in immunocompromised hosts, but is not considered a common human pathogen. There is concern about amphotericin B resistance in S. candida.

Capronia mansonii is a mesophilic black yeast that is a part of the Herpotrichiellaceae. The species is uncommon in nature but is saprotrophic in nature and been discovered on decaying plant matter, particularly wood. This fungus is naturally found in the Netherlands and has successfully been cultured in lab. It is a teleomorph of the ascomycota division and possesses brown spores.

Scytalidium ganodermophthorum is an anthroconidial ascomycete fungus in the Scytalidium genus. It is also known by its teleomorph name Xylogone ganodermophthora. It is the cause of yellow rot in lingzhi mushrooms and it is used in spalting as a pigmenting fungi.

<i>Pleurothecium</i> Genus of fungi

Pleurothecium is a genus of terrestrial and freshwater fungi in the family Pleurotheciaceae. It is typified by Pleurothecium recurvatum as the type species (Morgan) Höhn, which has the synonym of Carpoligna pleurotheciiF.A. Fernández & Huhndorf, Mycologia 9: 253. 1999.

References

  1. 1 2 3 4 5 Scott, D.B.; Deacon, J.W. (1983). "Magnaporthe rhizophila sp.nov., a dark mycelial fungus with a Phialophora conidial state, from cereal roots in South Africa". Transactions of the British Mycological Society. 81 (1): 77–81. doi:10.1016/s0007-1536(83)80206-x. ISSN   0007-1536.
  2. 1 2 3 Feng, Jia-Wei; Liu, Wei-Ting; Chen, Jia-Jie; Zhang, Chu-Long (2021-05-06). "Biogeography and Ecology of Magnaporthales: A Case Study". Frontiers in Microbiology. 12: 654380. doi: 10.3389/fmicb.2021.654380 . ISSN   1664-302X. PMC   8134742 . PMID   34025609.
  3. 1 2 Krause, R.A.; Webster, R.K. (1972). "The morphology, taxonomy, and sexuality of rice stem rot fungus, Magnaporthe salvinii". Mycologia (64): 103–114. doi:10.1080/00275514.1972.12019240.
  4. 1 2 3 Luo, J.; Walsh, E.; Zhang, N. (2014). "Four new species in Magnaporthaceae from grass roots in New Jersey Pine Barrens". Mycologia. 106 (3): 580–588. doi:10.3852/13-306. PMID   24871590. S2CID   1501279.
  5. 1 2 3 4 Luo, J.; Ning, Z. (2013). "Magnoporthiopsis, a new genus in Magnporthaceae (Ascomycota)". Mycologia. 105 (4): 1019–1029. doi:10.3852/12-359. PMID   23449077. S2CID   11109937.
  6. 1 2 Deacon, J.W. (1996). "Ecological Implications of Recognition Events in the Pre-Infection Stages of Root Pathogens". The New Phytologist. 133 (1): 135–145. doi:10.1111/j.1469-8137.1996.tb04349.x.
  7. 1 2 Zhang, N.; Zhao, Shuang; Shen, Qirong (2011). "A six-gene phylogeny reveals the evolution of mode of infection in the rice blast fungus and allied species". Mycologia. 103 (6): 1267–1276. doi:10.3852/11-022. PMID   21642347. S2CID   5212061.
  8. 1 2 Zhang, N.; Cai, G.; Price, D.C.; Crouch, J.A.; Gladieux, P. (2018). "Genome wide analysis of the transition to pathogenic lifestyles in Magnaporthales fungi". Scientific Reports. 8 (1): 5862. doi:10.1038/s41598-018-24301-6. PMC   5897359 . PMID   29651164.
  9. 1 2 Griffiths, D.A., The development of lignotubers in roots after infection by Verticillium dahliae Kleb, Canadian Journal of Microbiology
  10. 1 2 Henson, J (1992). "DNA hybridization and polymerase chain reaction (PCR) tests for identification of Gaumannomyces, Phialophora, and Magnaporthe isolates". Mycological Research. 96 (8): 629–636. doi:10.1016/S0953-7562(09)80488-7.