acute oak decline
{{Short description|Disease of oak trees}}
{{Infobox plant disease
| color =
| name = Acute oak decline
| image = Acute oak decline fig01.jpg
| caption = Stem bleeding in a tree affected with Acute oak decline
| common_names =
| causal_agents = Brenneria goodwinii and Gibsiella quercinecans
| hosts = Oaks
| vectors =
| EPPO_codes =
| distribution = United Kingdom
| treatment =
}}
Acute oak decline (AOD) is a disease that infects oak trees originally described in the UK. It mainly affects mature oak trees of over 50 years old of both Britain's native oak species: the pedunculate oak (Quercus robur) and the sessile oak (Quercus petraea). The disease is characterised by the trees bleeding or oozing a dark fluid from small lesions or splits in their bark.{{cite web|url=http://www.forestry.gov.uk/fr/INFD-7ULA6W|title=Symptoms of chronic oak decline|publisher=Forest Research|access-date=2009-09-26}} Unlike chronic oak decline, acute oak decline can lead to the death of trees within 4 to 5 years of symptoms appearing. The number of trees affected is thought to number in the low thousands, with a higher number of infected trees being found in the Midlands.
Causes of the disease
Acute Oak Decline is a complex tree decline disease{{Citation |last1=Denman |first1=Sandra |title=Temperate Oak Declines: Biotic and abiotic predisposition drivers |date=2022 |work=Forest Microbiology |pages=239–263 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780323850421000203 |access-date=2024-01-19 |publisher=Elsevier |language=en |doi=10.1016/b978-0-323-85042-1.00020-3 |isbn=978-0-323-85042-1 |last2=Brown |first2=Nathan |last3=Vanguelova |first3=Elena |last4=Crampton |first4=Bridget}} that cannot be explained by a single cause. It results from a combination of environmental factors weakening the trees and some biotic factors.
= Bacterial pathogens =
Two different species of bacteria, Brenneria goodwinii, Gibbsiella quercinecans, are repeatedly found in the decaying tissues of trees with AOD.{{Cite journal |last1=Brady |first1=Carrie |last2=Arnold |first2=Dawn |last3=McDonald |first3=James |last4=Denman |first4=Sandra |date=July 2017 |title=Taxonomy and identification of bacteria associated with acute oak decline |journal=World Journal of Microbiology and Biotechnology |language=en |volume=33 |issue=7 |page=143 |doi=10.1007/s11274-017-2296-4 |issn=0959-3993 |pmc=5486618 |pmid=28623563}} Laboratory experiment confirmed that these two species have the ability to cause tree tissue necrosis and possess virulence genes commonly found in plant pathogens.{{Cite journal |last1=Denman |first1=Sandra |last2=Doonan |first2=James |last3=Ransom-Jones |first3=Emma |last4=Broberg |first4=Martin |last5=Plummer |first5=Sarah |last6=Kirk |first6=Susan |last7=Scarlett |first7=Kelly |last8=Griffiths |first8=Andrew R |last9=Kaczmarek |first9=Maciej |last10=Forster |first10=Jack |last11=Peace |first11=Andrew |last12=Golyshin |first12=Peter N |last13=Hassard |first13=Francis |last14=Brown |first14=Nathan |last15=Kenny |first15=John G |date=2018-02-01 |title=Microbiome and infectivity studies reveal complex polyspecies tree disease in Acute Oak Decline |journal=The ISME Journal |language=en |volume=12 |issue=2 |pages=386–399 |doi=10.1038/ismej.2017.170 |issn=1751-7362 |pmc=5776452 |pmid=29028005|bibcode=2018ISMEJ..12..386D }} In addition to these two bacterial pathogens, the other microbes present in AOD affected trees is different from non-infected ones.{{Cite journal |last1=Denman |first1=Sandra |last2=Plummer |first2=Sarah |last3=Kirk |first3=Susan |last4=Peace |first4=Andrew |last5=McDonald |first5=James E. |date=2016-10-01 |title=Isolation studies reveal a shift in the cultivable microbiome of oak affected with Acute Oak Decline |url=https://www.sciencedirect.com/science/article/pii/S0723202016300704 |journal=Systematic and Applied Microbiology |volume=39 |issue=7 |pages=484–490 |doi=10.1016/j.syapm.2016.07.002 |pmid=27553488 |issn=0723-2020}}{{Cite journal |last1=Broberg |first1=Martin |last2=Doonan |first2=James |last3=Mundt |first3=Filip |last4=Denman |first4=Sandra |last5=McDonald |first5=James E. |date=2018-01-30 |title=Integrated multi-omic analysis of host-microbiota interactions in acute oak decline |journal=Microbiome |volume=6 |issue=1 |pages=21 |doi=10.1186/s40168-018-0408-5 |doi-access=free |issn=2049-2618 |pmc=5789699 |pmid=29378627}}
= Bark-boring beetle =
File:Agrilus biguttatus larvae.jpg
Most trees affected by AOD will display exit holes and galleries caused by the larvae of the two-spotted oak borer Agrilus biguttatus{{Cite journal |last1=Denman |first1=S. |last2=Brown |first2=N. |last3=Kirk |first3=S. |last4=Jeger |first4=M. |last5=Webber |first5=J. |date=2014-10-01 |title=A description of the symptoms of Acute Oak Decline in Britain and a comparative review on causes of similar disorders on oak in Europe |url=https://academic.oup.com/forestry/article-lookup/doi/10.1093/forestry/cpu010 |journal=Forestry |language=en |volume=87 |issue=4 |pages=535–551 |doi=10.1093/forestry/cpu010 |issn=0015-752X}}. Larvea of A. biguttatus and the bacterial pathogens are acting together in causing the disease, with the bacteria being more virulent and causing larger lesions when trees are infected with beetle larvae.{{Cite journal |last1=Doonan |first1=James M. |last2=Broberg |first2=Martin |last3=Denman |first3=Sandra |last4=McDonald |first4=James E. |date=2020-08-26 |title=Host–microbiota–insect interactions drive emergent virulence in a complex tree disease |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=287 |issue=1933 |doi=10.1098/rspb.2020.0956 |issn=0962-8452 |pmc=7482278 |pmid=32811286}} Researchers are still investing the potential role of A. biguttatus as a vector of the bacterial pathogens.
= Drought and nutrient limitation =
As other oak decline disease, AOD usually develops after the tree is being weakened by some environmental factors, called predisposing factors, such as water and nutrient limitation.{{Cite journal |last1=Brown |first1=Nathan |last2=Vanguelova |first2=Elena |last3=Parnell |first3=Stephen |last4=Broadmeadow |first4=Samantha |last5=Denman |first5=Sandra |date=January 2018 |title=Predisposition of forests to biotic disturbance: Predicting the distribution of Acute Oak Decline using environmental factors |url=https://linkinghub.elsevier.com/retrieve/pii/S0378112717314160 |journal=Forest Ecology and Management |language=en |volume=407 |pages=145–154 |doi=10.1016/j.foreco.2017.10.054}}
See also
References
{{reflist}}
Further reading
- {{Cite journal | last1 = Brady | first1 = C. | last2 = Denman | first2 = S. | last3 = Kirk | first3 = S. | last4 = Venter | first4 = S. | last5 = Rodríguez-Palenzuela | first5 = P. | last6 = Coutinho | first6 = T. | doi = 10.1016/j.syapm.2010.08.006 | title = Description of Gibbsiella quercinecans gen. nov., sp. nov., associated with Acute Oak Decline | journal = Systematic and Applied Microbiology | volume = 33 | issue = 8 | pages = 444–450 | year = 2010 | pmid = 21115313}}
Category:Bacterial tree pathogens and diseases