''Hyaloperonospora arabidopsidis'' is a species from the family

Peronosporaceae Peronosporaceae are a family of water moulds that contains 21 genera, comprising more than 600 species. Most of them are called downy mildews. Peronosporaceae are obligate biotrophic plant pathogens. They parasitise their host plants as an inte ...

. It is an obligate parasite and the causal agent of the downy mildew of the plant model organism ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. ''A. thaliana'' is considered a weed; it is found along the shoulders of roads and in disturbed land. A winter a ...

''. While ''H. arabidopsidis'' has for a long time been subsumed under ''Peronospora parasitica'' (now ''

Hyaloperonospora parasitica ''Hyaloperonospora parasitica'' is an oomycete from the family Peronosporaceae. It has been considered for a long time to cause downy mildew of a variety of species within the Brassicaceae, on which the disease can cause economically important da ...

''), recent studies have shown that ''H. parasitica'' is restricted to ''

Capsella bursa-pastoris ''Capsella bursa-pastoris'', known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, ...

'' as a host plant. Like the other ''

Hyaloperonospora ''Hyaloperonospora'' is a genus of oomycete, obligate, plant pathogens that was originally considered to be part of ''Peronospora''. Species in this group produce a disease called downy mildew and can infect many important crops. From the 19 down ...

'' species, ''H. arabidopsidis'' is highly specialized to ''

''.

References

Further reading