Login
Login

phytophthora

{{Short description|Genus of single-celled organisms}}

{{Automatic taxobox

| image = Prei papiervlekkenziekte Phytophthora porri on Allium porrum.jpg

| image_alt = Phytophthora porri on leek (Allium porrum)

| image_caption = Phytophthora porri on leek (Allium porrum)

| taxon = Phytophthora

| authority = de Bary 1876Heinrich Anton de Bary, Journal of the Royal Agricultural Society of England, ser. 2 12: 240 (1876)

| synonyms =

| synonyms_ref =

| subdivision_ranks = Species

| subdivision = See text

}}

File:Phytophthora kernoviae Rhododendron.jpg showing classic symptoms of Phytophthora kernoviae in the UK]]

Phytophthora (from Greek {{Lang|el|φυτόν}} (phytón), "plant" and {{Lang|el|φθορά}} ({{transliteration|el|phthorá}}), "destruction"; "the plant-destroyer") is a genus of plant-damaging oomycetes (water molds), whose member species cause economic losses on crops worldwide, as well as environmental damage in natural ecosystems. The cell wall of Phytophthora is made up of cellulose. The genus was first described by Heinrich Anton de Bary in 1875. Approximately 210 species have been described, although 100–500 undiscovered Phytophthora species are estimated to exist.Brasier CM, 2009. [http://www.fs.fed.us/psw/publications/documents/psw_gtr221/psw_gtr221.pdf#page=113 Phytophthora biodiversity: how many Phytohthora species are there?] In: Goheen EM, Frankel SJ, eds. Phytophthoras in Forest and Natural Ecosystems. Albany, CA, USA: USDA Forest Service: General Technical Rep rt PSW-GTR-221, 101–15.

Pathogenicity

File:SuddenOakDeath-USDA-Forest-Service.jpg]]

Phytophthora spp. are mostly pathogens of dicotyledons, and many are relatively host-specific parasites. P. cinnamomi, though, infects thousands of species ranging from club mosses, ferns, cycads, conifers, grasses, lilies, to members of many dicotyledonous families. Many species of Phytophthora are plant pathogens of considerable economic importance. P. infestans was the infective agent of the potato blight that caused the Great Famine of Ireland, and still remains the most destructive pathogen of solanaceous crops, including tomato and potato.Ristaino, J. B., Cooke, D.E.L., Acuña, I., Muñoz, M. 2020. The Threat of Late Blight to Global Food Security. Pages 101-133 in: In Emerging Plant Disease and Global Food Security. A. Records and J. B. Ristaino, eds. American Phytopathological Society Press, St. Paul. https://doi.org/10.1094/9780890546383.006 The soya bean root and stem rot agent, P. sojae, caused longstanding problems for the agricultural industry. In general, plant diseases caused by this genus are difficult to control chemically, thus the growth of resistant cultivars is the main management strategy. Other important Phytophthora diseases are:

  • P. agathidicida—causes collar-rot on New Zealand kauri (Agathis australis), New Zealand's most voluminous tree, an otherwise successful survivor of the Jurassic
  • P. cactorum—causes rhododendron root rot affecting rhododendrons, azaleas, and orchids, and causes bleeding canker in hardwood trees
  • P. capsici—infects Cucurbitaceae fruits, such as cucumbers and squash
  • P. cinnamomi—causes cinnamon root rot affecting forest and fruit trees, and woody ornamentals including arborvitaee, azalea, Chamaecyparis, dogwood, forsythia, Fraser fir, hemlock, Japanese holly, juniper, Pieris, rhododendron, Taxus, white pine, American chestnut and Australian woody plants, especially eucalypt and banksia.
  • P. citricola—causes root rot and stem cankers in citrus trees
  • P. fragariae—causes red root rot affecting strawberries
  • P. infestans causes the serious disease known as potato (late) blight: responsible for the Great Famine of Ireland.
  • P. kernoviae—pathogen of beech and rhododendron, also occurring on other trees and shrubs including oak, and holm oak. First seen in Cornwall, UK, in 2003.{{Cite journal | doi = 10.1017/S0953756205003357 | url = http://www.forestry.gov.uk/pdf/P_kernoviae_paper_2005.pdf/$FILE/P_kernoviae_paper_2005.pdf | title = Phytophthora kernoviae sp. Nov., an invasive pathogen causing bleeding stem lesions on forest trees and foliar necrosis of ornamentals in the UK | year = 2005 | author = Brasier, C | journal = Mycological Research | volume = 109 | pages = 853–9 | pmid = 16175787 | last2 = Beales | first2 = PA | last3 = Kirk | first3 = SA | last4 = Denman | first4 = S | last5 = Rose | first5 = J | issue = Pt 8 | access-date = 2009-03-04 | archive-date = 2012-03-15 | archive-url = https://web.archive.org/web/20120315191745/http://www.forestry.gov.uk/pdf/P_kernoviae_paper_2005.pdf/$FILE/P_kernoviae_paper_2005.pdf | url-status = dead }}
  • P. lateralis—causes cedar root disease in Port Orford cedar trees
  • P. megakarya—one of the cocoa black pod disease species, is invasive and probably responsible for the greatest cocoa crop loss in Africa
  • P. multivora—discovered in analysis of isolates with P. cinnamomi dieback infections of tuart forests of Southwest Australia, which were previously diagnosed as P. citricola. The species was found occurring on many other taxa, so named multivora.{{cite journal |last1=Scott |first1=PM |last2=Burgess |first2=TI |last3=Barber |first3=PA |last4=Shearer |first4=BL |last5=Stukely |first5=MJ |last6=Hardy |first6=GE |last7=Jung |first7=T |title=Phytophthora multivora sp. nov., a new species recovered from declining Eucalyptus, Banksia, Agonis and other plant species in Western Australia. |journal=Persoonia |date=June 2009 |volume=22 |pages=1–13 |doi=10.3767/003158509X415450 |pmid=20198133|pmc=2789538 }}
  • P. nicotianae—infects tobacco and onions
  • P. palmivora—causes fruit rot in coconuts and betel nuts
  • P. ramorum—infects over 60 plant genera and over 100 host species; causes sudden oak death[http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf_files/usdaprlist.pdf "APHIS List of Regulated Hosts and PlantsAssociated with Phytophthora ramorum" U.S. Animal and Plant Health Inspection Services] {{webarchive|url=https://web.archive.org/web/20061212185042/http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf_files/usdaprlist.pdf|date=2006-12-12}};
  • P. quercina—causes oak death
  • P. sojae—causes soybean root rot

Research beginning in the 1990s placed some of the responsibility for European forest die-back on the activity of imported Asian Phytophthoras.[http://www.sueddeutsche.de/,tt4m2/panorama/artikel/951/52899/ "Phytophthora: Asiatischer Pilz lässt die Bäume sterben" Süddeutschen Zeitung 11 Ma 2005]

In 2019, scientists in Connecticut were conducting experiments testing various methods to grow healthier Fraser trees when they accidentally discovered a new species of Phytophthora, which they called P. abietivora. The fact that these scientists so readily discovered a new species further suggests that there could be many more species waiting to be discovered.{{cite journal |title= Phytophthora abietivora, A New Species Isolated from Diseased Christmas Trees in Connecticut, U.S.A.|journal=Plant Disease |volume=103|issue=12|pages= 3057–3064|publisher=American Phytopathological Society |doi= 10.1094/PDIS-03-19-0583-RE|year=2019|last1=Li|first1=DeWei|last2=Schultes|first2=Neil|last3=LaMondia|first3=James|last4=Cowles|first4=Richard |pmid=31596694 |doi-access=free|bibcode=2019PlDis.103.3057L }}

Reproduction

Phytophthora species may reproduce sexually or asexually. In many species, sexual structures have never been observed, or have only been observed in laboratory matings. In homothallic species, sexual structures occur in single culture. Heterothallic species have mating strains, designated as A1 and A2. When mated, antheridia introduce gametes into oogonia, either by the oogonium passing through the antheridium (amphigyny) or by the antheridium attaching to the proximal (lower) half of the oogonium (paragyny), and the union producing oospores. Like animals, but not like most true fungi, meiosis is gametic, and somatic nuclei are diploid.

Asexual (mitotic) spore types are chlamydospores, and sporangia which produce zoospores. Chlamydospores are usually spherical and pigmented, and may have a thickened cell wall to aid in their role as a survival structure. Sporangia may be retained by the subtending hyphae (noncaducous) or be shed readily by wind or water tension (caducous) acting as dispersal structures. Also, sporangia may release zoospores, which have two unlike flagella which they use to swim towards a host plant.

Zoospores (and zoospores of Pythium, also in the Peronosporales) recognize not only hosts but particular locations on hosts. Phytophthora zoospores recognize and attach to specific root surface regions. This is a high degree of specificity at an early stage of cell development.{{cite book | date=1991 | publication-place=Boston, Ma, USA | first2=Lynn | editor1-last=Cole | pages=3–23/xxv+555 | editor1-first=Garry T. | editor2-last=Hoch | editor2-first=Harvey C. | title=The Fungal Spore and Disease Initiation in Plants and Animals | isbn=978-1-4899-2635-7 | id={{isbn|978-0-306-43454-9}}. {{isbn|978-1-4899-2637-1}} | oclc=913636088 | last1=Nicholson | first1=Ralph L. | last2=Epstein | chapter=Adhesion of Fungi to the Plant Surface | doi=10.1007/978-1-4899-2635-7_1 | s2cid=82631781}}

Image:Phytophthora life cycle.png

Image:Phytophtora reproduction.png

Evolution and resemblance to fungi

Phytophthora is sometimes referred to as a fungus-like organism, but it is classified under a different clade altogether: SAR supergroup (Harosa) (also under Stramenopila and previously under Chromista). This is a good example of convergent evolution: Phytophthora is morphologically very similar to true fungi yet its evolutionary history is completely distinct. In contrast to fungi, SAR supergroup is more closely related to plants than to animals. Whereas fungal cell walls are made primarily of chitin, Phytophthora cell walls are constructed mostly of cellulose. Ploidy levels are different between these two groups; Phytophthora species have diploid (paired) chromosomes in the vegetative (growing, nonreproductive) stage of life, whereas fungi are almost always haploid in this stage. Biochemical pathways also differ, notably the highly conserved lysine synthesis path.{{citation needed|date=May 2023}}.

Species

The NCBI lists:{{cite web|author1=|title=Phytophthora|url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=4783&lvl=3&keep=1&srchmode=1&unlock|website=NCBI taxonomy|publisher=National Center for Biotechnology Information|access-date=18 June 2018|location=Bethesda, MD|language=en}}

{{div col|colwidth=22em}}

Phytophthora betacei

{{div col end}}

''References''

{{Reflist|2Corcobado, T., Cech, T.L., Daxer, A. et al. Phytophthora, Nothophytophthora and Halophytophthora diversity in rivers, streams and riparian alder ecosystems of Central Europe. Mycol Progress 22, 50 (2023). https://doi.org/10.1007/s11557-023-01898-1|refs=

{{cite journal | last1 = Werres | first1 = Sabine | last2 = Marwitz | first2 = Rainer | last3 = Man In't veld | first3 = Willem A. | last4 = De Cock | first4 = Arthur W. A. M. | last5 = Bonants | first5 = Peter J. M. | last6 = De Weerdt | first6 = Marjanne | last7 = Themann | first7 = Karin | last8 = Ilieva | first8 = Elena | date = 2001 | title = Phytophthora ramorum sp. nov., a new pathogen on Rhododendron and Viburnum | journal = Mycological Research | volume = 105 | issue = 10 | pages = 1155–1165 | doi = 10.1016/S0953-7562(08)61986-3}}

{{cite journal | last1 = Hong | first1 = C.X. | last2 = Gallegly | first2 = M.E. | last3 = Richardson | first3 = P.A. | last4 = Kong | first4 = P. | last5 = Moorman | first5 = G.W. | last6 = Lea-Cox | first6 = J.D. | last7 = Ross | first7 = D.S. | date = 2010 | title = Phytophthora hydropathica, a new pathogen identified from irrigation water, Rhododendron catawbiense and Kalmia latifolia | journal = Plant Pathology | volume = 59 | issue = 5 | pages = 913–921 | doi = 10.1111/j.1365-3059.2010.02323.x| bibcode = 2010PPath..59..913H }}

}}Coomber, A., Saville, A., Carbone, I. and Ristaino, J. 2023. An open T base phylogeny for emerging Phytophthora species.  PLOS ONE: https://doi.org/10.1371/journal.pone.0283540

Further reading

  • Lucas, J.A. et al. (eds.) (1991) Phytophthora based n a symposium held at Trinity College, Dublin, Ireland September 1200. British Mycologic l Society, Cambridge University Press, Cambridge, UK, {{ISBN|0-521-40080-5}};
  • Erwin, Donald C. and Ribe ro, Olaf K. (1996) Phytophthora Diseases Worldwide American Phytopathological Society Press, St Paul, Minnesota, {{ISBN|0-89054-212-0}}
  • Erwin, Donald C. (1983) Phytophthora: its biology, ta onomy, ecology, and pathology American Phytopathological Society Press, St. Paul, Minnesota, {{ISBN|0-89054-050-0}}
  • [https://web.archive.org/web/20061212185042/http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf_files/usdaprlist.pdf "APHIS List of Regulated Hosts and Plants Associated with Phytophthora ram] [https://web.archive.org/web/20061212185042/http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf_files/usdaprlist.pdf rum" U.S. Animal and Plant Health Inspection Services]
  • [http://www.naturebase.net/content/category/4/302/97/ "Dieback" Department of Env] [http://www.naturebase.net/content/category/4/302/97/ ronment and Conservation, Western Australia]
  • {{ Cite book

| language = en

| year = 2013

| number = 2

| pages = xi+244

| last = Lamour

| first = Kurt

| editor-first1 = K.

| editor-last1 = Lamour

| id = 978-1-78064-093-8

| lccn = 2012042152

| doi = 10.1079/9781780640938.0000

| publisher = CABI (Centre for Agriculture and Bioscience International)

| series = CABI Plant Protection Series

| title = Phytophthora: A Global Perspective

| isbn = 9781780640938

}}

External links

{{Wikispecies|Phytophthora}}

{{Commons category}}

  • [https://web.archive.org/web/20061014125542/http://www.btny.purdue.edu/USDA-ARS/Goodwin_lab/results/Phytoph_biblio.html Goodwin, Stephn B. (January 2001) "Phytophthora Bibliography" Purdue University]
  • [https://web.archive.org/web/20070506074931/http://www.ladybug.uconn.edu/factsheets/tp_05_phytophthora.html Abbey, Tim (2005) "Pytophthora Dieback and Root Rot" College of Agriculture and Natural Resources, University of Con] [https://web.archive.org/web/20070506074931/http://www.ladybug.uconn.edu/factsheets/tp_05_phytophthora.html ecticut]
  • [http://www.bartlett.com/resources/Phytophthora-Canker.cfm "Phytophthora Canker – Identification, Biology and Management"] Bartlett TreeExperts Online Resource Library
  • [http://www.bartlett.com/resources/Phytophthora-Root-Rot.cfm "Phytophthora Root Rot – Identification, Biology andManagement"] Bartlett Tree Experts Online Resource Library
  • [http://www.dwg.org.au/ Dieback Working Group] – Western Australia

{{Taxonbar|from=Q311294}}

{{Authority control}}

Category:Water mould plant pathogens and diseases

Category:Oomycete genera