''Phaeosphaeria nodorum'' (syn. ''Stagonospora nodorum'', synonym and correct taxonomic name: ''Parastagonospora nodorum'') is a major fungal pathogen of wheat ('' Triticum aestivum''), causing the disease Septoria nodorum blotch. It is a member of the

Dothideomycetes Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1300 genera and over 19,000 known species. Traditionally, most of its members were included in the loculoascomycetes, which is not pa ...

, a large fungal taxon that includes many important plant pathogens affecting all major crop plant families.

Disease cycle

The infection occurs in repeated cycles of both asexual and sexual infection throughout the growing season. New rounds of infection are initiated by rain-splash or wind dispersal of spores. Infection begins when spores land on leaf tissue. The spores rapidly germinate to produce long, branching threadlike structures, called hyphae. The hyphae invade the leaf, using specialised branches to gain entry to the outermost layer of cells on the leaves. They can also grow directly through pores in the leaves. The hyphae rapidly colonize the leaves and begin to produce asexual fruiting bodies.

Management

Seed treatment

Seed treatment In agriculture and horticulture, a seed treatment is any additional material added to the seed. By the amount of material added, it can be divided into: * A seed dressing, typically containing a "protectant" ( pesticide) applied to the seed and p ...

with

fungicide Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality ...

- already used for bunts and smuts - has been discovered to eliminate seed transmission in wheat.

Model organism

''Parastagonospora nodorum'' is an experimentally tractable organism, which is easily handled in defined media. It was one of the first fungal pathogens to be genetically manipulated. ''Parastagonospora nodorum'' has been a model for fungicide development and emerged as a model for dothideomycete pathology.

Genetics and genomics

Genomic resources

''Parastagonospora nodorum'' has been sequenced and annotatedHANE JK, LOWE, RGT, SOLOMON, PS, TAN K-C, SCHOCH, CL, SPATAFORA, JWB, CROUS, PC, KODIRA, C, BIRREN, BW, GALAGAN, JE, TORRIANI, SFF, MCDONALD, BA & OLIVER (2007)
Dothideomycete-plant interactions illuminated by genome sequencing and EST analysis of the wheat pathogen ''Stagonospora nodorum''.
''Plant Cell'' 19:3347-3368. by the

Broad Institute The Eli and Edythe L. Broad Institute of MIT and Harvard (IPA: , pronunciation respelling: ), often referred to as the Broad Institute, is a biomedical and genomic research center located in Cambridge, Massachusetts, United States. The insti ...

Genetics

Gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

s for

signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellula ...

factors are vital to the

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...

process.

Functional genomics Functional genomics is a field of molecular biology that attempts to describe gene (and protein) functions and interactions. Functional genomics make use of the vast data generated by genomic and transcriptomic projects (such as genome sequencing ...

investigations by the Solomon group have dissected the roles of several, by disabling them and observing how they fail. In Solomon ''et al.'', 2005 & Solomon ''et al.'', 2006 they demonstrate how

sporulation In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

, pathogenicity, and stress tolerance are centrally related to several kinases, ' (a

MAP kinase A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of protein kinase that is specific to the amino acids serine and threonine (i.e., a serine/threonine-specific protein kinase). MAPKs are involved in directing cellular response ...

) and ', ', and ' ( calmodulin kinases).

Taxonomy

In 2013, Quaedvlieg et al. introduced a new combination for this species: ''Parastagonospora nodorum'' (Berk.) Quaedvlieg, Verkley & Crous. In the article named "Sizing up Septoria" they showed that the type of the fungal genus ''Stagonospora'' ('' Stagonospora paludosa'') actually clustered inside the ''Massarinaceae'' and not in the ''Phaeosphaeriaceae'' as was previously assumed. They also showed that the type of the genus ''Phaeosphaeria'' (''P. oryzae'') does not cluster near ''Stagonospora nodorum''. This means that both the ''Phaeosphaeria'' and ''Stagonospora'' names for this species are wrong. This caused that the ''Phaeosphaeriaceae'' located genus previously known as ''Stagonospora'', incorporating several important pathogens on grasses (e.g. ''Stagonospora nodorum'' and ''S. avenae''), was subsequently renamed into ''Parastagonospora'' with ''Parastagonospora nodorum'' being the type of this genus.

References

External links

Sizing up Septoria (Studies in Mycology 75: 307–390).
{{Taxonbar, from=Q4314880 Phaeosphaeriaceae Wheat diseases Fungal plant pathogens and diseases Fungi described in 1845 Taxa named by Miles Joseph Berkeley