Xylella fastidiosa#CFBP8071

Xylella fastidiosa is the first-proposed species in the genus Xylella and the only species until 2016. The genus Xyella {{au|Wells et al. 1987}} currently consists of two species, Xylella fastidiosa {{au|Wells et al. 1987}} and Xylella taiwanensis {{au|Su et al. 2016}}.{{Lpsn|genus/xyella}} Xylella fastidiosa in turn consists of several subspecies, each with own preferred host plants and geographic origin:

• {{visible anchor|subsp. fastidiosa|text=X. f. subsp. fastidiosa}} {{au|(Wells et al. 1987) Schaad et al. 2009}} is defined around the original type strain and is the best-studied so far. It is mainly known for Pierce's disease of grapevines and leaf scorch of almond.{{cite journal |last1=Badel |first1=J. L. |last2=Zambolim |first2=L. |title=Coffee bacterial diseases: a plethora of scientific opportunities |journal=Plant Pathology |date=April 2019 |volume=68 |issue=3 |pages=411–425 |doi=10.1111/ppa.12966|bibcode=2019PPath..68..411B }} It also affects alfalfa and maple.{{cite journal |last1=Schaad |first1=Norman W. |last2=Postnikova |first2=Elena |last3=Lacy |first3=George |last4=Fatmi |first4=M'Barek |last5=Chang |first5=Chung-Jan |title=Xylella fastidiosa subspecies: X. fastidiosa subsp piercei, subsp. nov., X. fastidiosa subsp. multiplex subsp. nov., and X. fastidiosa subsp. pauca subsp. nov. |journal=Systematic and Applied Microbiology |date=January 2004 |volume=27 |issue=3 |pages=290–300 |doi=10.1078/0723-2020-00263|pmid=15214634 |bibcode=2004SyApM..27..290S }} It is thought to have originated in southern Central America.
• Identical to invalid name "X. f. subsp. piercei" {{au|Schaad et al. 2004}}.{{cite journal |last1=Schaad |first1=Norman W. |last2=Postnikova |first2=Elena |last3=Lacy |first3=George |last4=Fatmi |first4=M'Barek |last5=Chang |first5=Chung-Jan |title=Xylella fastidiosa subspecies: X. fastidiosa subsp piercei, subsp. nov., X. fastidiosa subsp. multiplex subsp. nov., and X. fastidiosa subsp. pauca subsp. nov. |journal=Systematic and Applied Microbiology |date=December 2004 |volume=27 |issue=6 |pages=763 |doi=10.1078/0723202042369848|bibcode=2004SyApM..27..763S }}
• X. f. subsp. multiplex {{au|Schaad et al. 2009}} affects many trees, including stone-fruit ones such as peaches and plums, and is thought to originate in temperate and southern North America. It also affects elm, grape, and sycamore.
• "X. f. subsp. pauca" {{au|Schaad et al. 2004}} is believed to have originated in South America. It is the causal agent of citrus variegated chlorosis (CVC) in Brazil.{{cite journal | last1=Sicard | first1=Anne | last2=Zeilinger | first2=Adam R. | last3=Vanhove | first3=Mathieu | last4=Schartel | first4=Tyler E. | last5=Beal | first5=Dylan J. | last6=Daugherty | first6=Matthew P. | last7=Almeida | first7=Rodrigo P.P. | title=Xylella fastidiosa: Insights into an Emerging Plant Pathogen | journal=Annual Review of Phytopathology | publisher=Annual Reviews | volume=56 | issue=1 | date=2018-08-25 | issn=0066-4286 | doi=10.1146/annurev-phyto-080417-045849 | pages=181–202| pmid=29889627 | bibcode=2018AnRvP..56..181S | s2cid=48353386 | url=https://hal.inrae.fr/hal-02791754/file/Publis18-bgpi-028_sicard_xyllela_1.pdf }} {{small|1=(AS ORCID: [http://orcid.org/0000-0002-0575-195X 0000-0002-0575-195X])}}. It also affects South American coffee crops, causing coffee leaf scorch.
• "X. f. subsp. sandyi" {{au|Schuenzel et al. 2005}} is thought to have originated in the southern part of the United States, and is notable for causing oleander leaf scorch.{{Cite journal|url=https://www.cabi.org/isc/datasheet/57195|title=Xylella fastidiosa (Pierce's disease of grapevines)|website=www.cabi.org|date=2016 |doi=10.1079/cabicompendium.57195 |access-date=2017-11-06 |last1=Robinson |first1=R. |volume=CABI Compendium |doi-access=free }}
• "X. f. subsp. tashke" {{au|Randell et al., 2009}} is proposed to include isolates associated with Chitalpa tashkentensis leaf scorch in Southwestern USA. Whether it is causative is unknown. Whether it forms a distinct group that can be called a subspecies is also unknown.
• "X. f. subsp. morus" {{au|Nunney et al. 2014}} includes a strain associated with mulberry leaf scorch in the eastern USA and California. It is genetically distinct enough to be its own subspecies.

The three X. fastidiosa subspecies by Schaad et al. were outlined in the same 2004 publication. Two of them were made valid according to the Prokaryotic Code in 2009. No reason was given for not validating the third subspecies, pauca.{{cite journal |title=List of new names and new combinations previously effectively, but not validly, published |journal=International Journal of Systematic and Evolutionary Microbiology |date=1 May 2009 |volume=59 |issue=5 |pages=923–925 |doi=10.1099/ijs.0.013961-0|doi-access=free }}

X. taiwanensis affects Pyrus pyrifolia in Taiwan, causing leaf scorch. It has not spread to the EU.{{cite journal |last1=Bragard |first1=Claude |last2=Baptista |first2=Paula |last3=Chatzivassiliou |first3=Elisavet |last4=Di Serio |first4=Francesco |last5=Gonthier |first5=Paolo |last6=Jaques Miret |first6=Josep Anton |last7=Justesen |first7=Annemarie Fejer |last8=MacLeod |first8=Alan |last9=Magnusson |first9=Christer Sven |last10=Milonas |first10=Panagiotis |last11=Navas-Cortes |first11=Juan A |last12=Parnell |first12=Stephen |last13=Potting |first13=Roel |last14=Stefani |first14=Emilio |last15=Thulke |first15=Hans-Hermann |last16=Van der Werf |first16=Wopke |last17=Civera |first17=Antonio Vicent |last18=Yuen |first18=Jonathan |last19=Zappalà |first19=Lucia |last20=Chen |first20=Jianchi |last21=Migheli |first21=Quirico |last22=Vloutoglou |first22=Irene |last23=Streissl |first23=Franz |last24=Reignault |first24=Philippe Lucien |title=Pest categorisation of Xylella taiwanensis |journal=EFSA Journal |date=January 2023 |volume=21 |issue=1 |pages=e07736 |doi=10.2903/j.efsa.2023.7736|pmid=36698497 |pmc=9854164 |hdl=11380/1302450 |hdl-access=free }} It was originally proposed to be a subspecies of X. f., but the large divergence lead to the proposal of a separate species.

Xylella fastidiosa is rod-shaped, and at least one subspecies has two types of pili on only one pole; longer, type IV pili are used for locomotion, while shorter, type I pili assist in biofilm formation inside their hosts. As demonstrated using a PD-related strain, the bacterium has a characteristic twitching motion that enables groups of bacteria to travel upstream against heavy flow, such as that found in xylem vessels.{{Cite journal|last1=Meng|first1=Yizhi|last2=Li|first2=Yaxin|last3=Galvani|first3=Cheryl D.|last4=Hao|first4=Guixia|last5=Turner|first5=James N.|last6=Burr|first6=Thomas J.|last7=Hoch|first7=H. C.|date=2005-08-15|title=Upstream Migration of Xylella fastidiosa via Pilus-Driven Twitching Motility|journal=Journal of Bacteriology|language=en|volume=187|issue=16|pages=5560–5567|doi=10.1128/jb.187.16.5560-5567.2005|issn=0021-9193|pmid=16077100|pmc=1196070}} It is obligately insect-vector transmitted from xylem-feeding insects directly into xylem, but infected plant material for vegetative propagation (e.g. grafting) can produce mature plants that also have an X. fastidiosa disease.{{Cite web|url=http://edis.ifas.ufl.edu/pdffiles/IN/IN17400.pdf|title=Xylella Fastidiosa Diseases and Their Leafhopper Vectors|last1=Mizell|first1=Russell F.|last2=Andersen|date=January 2003|website=University of Florida IFAS Extension|access-date=November 30, 2017|last3=Tipping|archive-date=February 25, 2021|archive-url=https://web.archive.org/web/20210225083954/https://edis.ifas.ufl.edu/pdffiles/IN/IN17400.pdf|url-status=dead}} In the wild, infections tend to occur during warmer seasons, when insect vector populations peak. The bacterium is not seed transmitted, but instead is transmitted through "xylem feed-ing, suctorial homopteran insects such as sharpshooter leafhoppers and spittle bugs"{{Cite journal |title=Populations of Xylella fastidiosa in Plants Required for Transmission by an Efficient Vector |journal=Phytopathology |year=1997 |language=en |doi=10.1094/phyto.1997.87.12.1197|last1=Hill |first1=B. L. |last2=Purcell |first2=A. H. |volume=87 |issue=12 |pages=1197–1201 |pmid=18945018 |doi-access=free |bibcode=1997PhPat..87.1197H }} and has been historically difficult to culture (fastidious),{{Cite journal|last1=Coletta-Filho|first1=Helvécio Della|last2=Carvalho|first2=Sérgio Alves|last3=Silva|first3=Luis Fernando Carvalho|last4=Machado|first4=Marcos Antonio|date=2014-07-01|title=Seven years of negative detection results confirm that Xylella fastidiosa, the causal agent of CVC, is not transmitted from seeds to seedlings|journal=European Journal of Plant Pathology|language=en|volume=139|issue=3|pages=593–596|doi=10.1007/s10658-014-0415-8|bibcode=2014EJPP..139..593C |s2cid=15561623|issn=0929-1873}}{{Cite journal|last=Purcell|first=Alexander|date=2013-08-04|title=Paradigms: Examples from the Bacterium Xylella fastidiosa|journal=Annual Review of Phytopathology|volume=51|issue=1|pages=339–356|doi=10.1146/annurev-phyto-082712-102325|pmid=23682911|bibcode=2013AnRvP..51..339P |issn=0066-4286}} as its specific epithet, fastidiosa, reflects.

X. fastidiosa has a two-part lifecycle, which occurs inside an insect vector and inside a susceptible plant. While the bacterium has been found across the globe, only once the bacterium reaches systemic levels do symptoms present themselves. Once established in a new region, X. fastidiosa spread is dependent on the obligate transmission by xylem-sap feeding insect.{{Cite journal |last1=Cornara |first1=Daniele |last2=Morente |first2=Marina |last3=Markheiser |first3=Anna |last4=Bodino |first4=Nicola |last5=Tsai |first5=Chi-Wei |last6=Fereres |first6=Alberto |last7=Redak |first7=Richard A. |last8=Perring |first8=Thomas M. |last9=Lopes |first9=Joao Roberto Spotti |display-authors=4 |year=2019 |title=An overview on the worldwide vectors of Xylella fastidiosa |journal=Entomologia Generalis |volume=39 |issue=3–4 |pages=157–181 |doi=10.1127/entomologia/2019/0811}} Within susceptible plant hosts, X. fastidiosa forms a biofilm-like layer within xylem cells and tracheary elements that can completely block the water transport in affected vessels.{{Cite journal |last1=Chatterjee |first1=Subhadeep |last2=Almeida |first2=Rodrigo P. P. |last3=Lindow |first3=Steven |date=2008-08-04 |title=Living in two Worlds: The Plant and Insect Lifestyles of Xylella fastidiosa |journal=Annual Review of Phytopathology |volume=46 |issue=1 |pages=243–271 |doi=10.1146/annurev.phyto.45.062806.094342 |issn=0066-4286 |pmid=18422428|bibcode=2008AnRvP..46..243C }}

{{visible anchor|EB92-1}} is a significantly less pathogenic strain of X. fastidiosa which is used for biocontrol against its relatives.

{{Unbulleted list citebundle|{{cite book | editor-last1=Gross | editor-first1=Dennis C. | editor-last2=Lichens-Park | editor-first2=Ann | editor-last3=Kole | editor-first3=Chittaranjan | title=Genomics of plant-associated bacteria | publication-place=Heidelberg | date=2014 | isbn=978-3-642-55378-3 | oclc=881817015 | id={{isbn|978-3-642-55377-6}} | pages=x+278}}{{rp|pages=177–202}}|{{cite journal | last1=Zhang | first1=Shujian | last2=Flores-Cruz | first2=Zomary | last3=Kumar | first3=Dibyendu | last4=Chakrabarty | first4=Pranjib | last5=Hopkins | first5=Donald L. | last6=Gabriel | first6=Dean W. | title=The Xylella fastidiosa Biocontrol Strain EB92-1 Genome Is Very Similar and Syntenic to Pierce's Disease Strains | journal=Journal of Bacteriology | publisher=American Society for Microbiology | volume=193 | issue=19 | year=2011 | issn=0021-9193 | doi=10.1128/jb.05430-11 | pages=5576–5577 | pmid=21914886 | pmc=3187439 | s2cid=7068164}}}}

There is very little genomic distance between pathogenic and EB92-1 strains. However, 10 genes believed to be responsible for causing diseases in plants are missing. EB92-1 not only protects against X. fastidiosa infection; it also protects against Citrus Huanglongbing, which is caused by Liberibacter.{{cite journal |last1=Hopkins |first1=D. L. |last2=Ager |first2=K. L. |title=Biological Control of Citrus Huanglongbing with EB92-1, a Benign Strain of Xylella fastidiosa |journal=Plant Disease |date=1 October 2021 |volume=105 |issue=10 |pages=2914–2918 |doi=10.1094/PDIS-02-21-0362-RE|doi-access=free |pmid=33822659 |bibcode=2021PlDis.105.2914H }}

Significant variation in symptoms is seen between diseases, though some symptoms are expressed across species. On a macroscopic scale, plants infected with a X. fastidiosa-related disease exhibit symptoms of water, zinc, and iron deficiencies,{{cite book |last1=Almeida |first1=Rodrigo P.P. |url= |title=Manual of Security Sensitive Microbes and Toxins |last2=Coletta-Filho |first2=Helvécio D. |last3=Lopes |first3=João R.S. |publisher=CRC Press |year=2014 |isbn=9780367378745 |editor1-last=Liu |editor1-first=Dongyou |edition=1 |chapter=Xylella fastidiosa}} manifesting as leaf scorching and stunting in leaves turning them yellowish-brown, gummy substance around leaves, fruit reduction in size and quality, and overall plant height. As the bacterium progressively colonizes xylem tissues, affected plants often block off their xylem tissue, which can limit the spread of this pathogen; blocking can occur in the form of polysaccharide-rich gels, tyloses, or both. These plant defenses do not seem to hinder the movement of X. fastidiosa. Occlusion of vascular tissue, while a normal plant response to infection, makes symptoms significantly worse; as the bacterium itself also reduces vascular function, a 90% reduction of vascular hydraulic function was seen in susceptible Vitis vinifera.{{Cite journal|last1=Sun|first1=Qiang|last2=Sun|first2=Yuliang|last3=Walker|first3=M. Andrew|last4=Labavitch|first4=John M.|date=2013-03-01|title=Vascular Occlusions in Grapevines with Pierce's Disease Make Disease Symptom Development Worse|journal=Plant Physiology|language=en|volume=161|issue=3|pages=1529–1541|doi=10.1104/pp.112.208157|issn=0032-0889|pmid=23292789|pmc=3585614}} This bacterium rarely completely blocks vascular tissue. There usually is a slight amount of vascular function that keeps the plant alive, but makes its fruit or branches die, making the specific plant economically nonproductive. This can cause a massive drop on supply of quality fruit. Smaller colonies usually occur throughout a high proportion of xylem vessels of a symptomatic plant.{{citation needed|date=November 2022}}

X. fastidiosa is a Gram-negative, xylem-limited illness that is spread by insects. It can damage a variety of broadleaved tree species that are commonly grown in the United States. X. fastidiosa can be found in about 600 different plant species.{{citation needed|date=November 2022}}

• Withering and desiccation of branches
• Leaf chlorosis
• Dwarfing or lack of growth of the plant
• Drooping appearance and shorter internodes
• Shriveled fruits on infected plants
• Premature fruit abscission
• gum-like substance on leaves
• hardening and size reduction of fruit

(X. f. subsp. fastidiosa) Severe PD symptoms include shriveled fruit, leaf scorching, and premature abscission of leaves, with bare petioles remaining on stems.{{Cite journal |last1=Hopkins |first1=D. L. |last2=Purcell |first2=A. H. |date=2002-10-01 |title=Xylella fastidiosa: Cause of Pierce's Disease of Grapevine and Other Emergent Diseases |journal=Plant Disease |volume=86 |issue=10 |pages=1056–1066 |doi=10.1094/pdis.2002.86.10.1056 |issn=0191-2917 |pmid=30818496 |doi-access=free|bibcode=2002PlDis..86.1056H }}

(X. f. subsp. pauca) This disease is named after the characteristic spotty chlorosis on upper sides of citrus leaves. Fruits of infected plants are small and hard.

Some isolates cause {{visible anchor|Almond leaf scorch}}, in California that includes {{visible anchor|CFBP8071}} (fastidiosa), {{visible anchor|M23}} (fastidiosa), and {{visible anchor|M12}} (multiplex).{{cite journal | last1=Moralejo | first1=E. | last2=Borràs | first2=D. | last3=Gomila | first3=M. | last4=Montesinos | first4=M. | last5=Adrover | first5=F. | last6=Juan | first6=A. | last7=Nieto | first7=A. | last8=Olmo | first8=D. | last9=Seguí | first9=G. | last10=Landa | first10=B. B. | title=Insights into the epidemiology of Pierce's disease in vineyards of Mallorca, Spain | journal=Plant Pathology | publisher=British Society for Plant Pathology (Wiley) | volume=68 | issue=8 | date=2019-08-07 | issn=0032-0862 | doi=10.1111/ppa.13076 | pages=1458–1471 | bibcode=2019PPath..68.1458M | s2cid=199641165| url=https://zenodo.org/record/3560221 }}{{cite journal |last1=Chen |first1=J. |last2=Xie |first2=G. |last3=Han |first3=S. |last4=Chertkov |first4=O. |last5=Sims |first5=D. |last6=Civerolo |first6=E. L. |title=Whole genome sequences of two Xylella fastidiosa strains (M12 and M23) causing almond leaf scorch disease in California |journal=Journal of Bacteriology |date=September 2010 |volume=192 |issue=17 |pages=4534 |doi=10.1128/JB.00651-10 |pmid=20601474|pmc=2937377 }}

(X. f. subsp. pauca) Coffee Leaf Scorch (CLS) is a disease caused by the causal agent Xylella fastidiosa that is economically significant in Brazil.{{Cite journal |last1=Li |first1=W.-B. |last2=Pria |first2=W. D. |last3=Teixeira |first3=D. C. |last4=Miranda |first4=V. S. |last5=Ayres |first5=A. J. |last6=Franco |first6=C. F. |last7=Costa |first7=M. G. |last8=He |first8=C.-X. |last9=Costa |first9=P. I. |last10=Hartung |first10=J. S. |date=2001-05-01 |title=Coffee Leaf Scorch Caused by a Strain of Xylella fastidiosa from Citrus |url=https://apsjournals.apsnet.org/doi/10.1094/PDIS.2001.85.5.501 |journal=Plant Disease |volume=85 |issue=5 |pages=501–505 |doi=10.1094/PDIS.2001.85.5.501 |pmid=30823125 |bibcode=2001PlDis..85..501L |issn=0191-2917|hdl=11449/38427 |hdl-access=free }} Citrus variegated chlorosis (CVC), another significant disease in this region caused by a strain of X. fastidiosa has been shown to infect coffee plants with CLS. The disease has also been found in Costa Rica's Central Valley where it is referred to as ‘crespera’ disease by coffee growers.{{Cite journal |last1=Montero-Astúa |first1=Mauricio |last2=Chacón-Díaz |first2=Carlos |last3=Aguilar |first3=Estela |last4=Rodríguez |first4=Carlos Mario |last5=Garita |first5=Laura |last6=Villalobos |first6=William |last7=Moreira |first7=Lisela |last8=Hartung |first8=John S. |last9=Rivera |first9=Carmen |date=October 2008 |title=Isolation and molecular characterization of Xylella fastidiosa from coffee plants in Costa Rica |url=http://link.springer.com/10.1007/s12275-008-0072-8 |journal=The Journal of Microbiology |language=en |volume=46 |issue=5 |pages=482–490 |doi=10.1007/s12275-008-0072-8 |pmid=18974947 |s2cid=40097733 |issn=1225-8873|hdl=10669/76372 |hdl-access=free }} Symptoms of the bacterial infection in coffee plants feature curling leaf margins, chlorosis and irregularly shaped leaves, stunting and reduced plant growth, and branch atrophy. The disease reduced coffee production by up to 30% in plantations across Brazil.

X. fastidiosa was discovered in Apulia, Italy in 2013 for the first time as a destructive disease agent of olive trees and likely came from strains present in asymptomatic plant material imported from Costa Rica. The strains were of a single origin in subspecies pauca.{{Cite journal |last1=Sicard |first1=Anne |last2=Saponari |first2=Maria |last3=Vanhove |first3=Mathieu |last4=Castillo |first4=Andreina I. |last5=Giampetruzzi |first5=Annalisa |last6=Loconsole |first6=Giuliana |last7=Saldarelli |first7=Pasquale |last8=Boscia |first8=Donato |last9=Neema |first9=Claire |last10=Almeida |first10=Rodrigo P. P. |year=2021 |title=Introduction and adaptation of an emerging pathogen to olive trees in Italy |journal=Microbial Genomics |volume=7 |issue=12 |pages=000735 |doi=10.1099/mgen.0.000735 |doi-access=free |issn=2057-5858 |pmc=8767334 |pmid=34904938}}

X. fastidiosa occurs worldwide, though its diseases are most prominent in riparian habitats including the southeastern United States, California, and South America.

Symptoms of X. fastidiosa diseases worsen during hot, dry periods in the summer; lack of water and maximum demand from a full canopy of leaves, combined with symptoms due to disease, stress infected plants to a breaking point. Cold winters can limit the spread of the disease, as it occurs in California, but not in regions with milder winters such as Brazil. Additionally, dry summers seem to delay symptom development of PD in California.

Any conditions that increase vector populations can increase disease incidence, such as seasonal rainfall and forests or tree cover adjacent to crops, which serve as alternate food sources and overwintering locations for leafhoppers.

Alexander Purcell, an expert on X. fastidiosa, hypothesized that plants foreign to X. fastidiosa{{'}}s area of origin, the neotropical regions, are more susceptible to symptom development. Thus, plants from warmer climates are more resistant to X. fastidiosa disease development, while plants from areas with harsher winters, such as grapes, are more severely affected by this disease.

X. fastidiosa has a very wide host range; as of 2020, its known host range was 595 plant species, with 343 species confirmed by two different detection methods, in 85 botanical families.{{Cite journal|last=European Food Safety Authority|date=2020|title=Scientific report on the update of the Xylella spp. host plant database – systematic literature search up to 30 June 2019|journal=EFSA Journal|language=en|volume=18|issue=4|pages=61|doi=10.2903/j.efsa.2020.6114|pmid=32874307|pmc=7448098|issn=1831-4732|doi-access=free}} Most X. fastidiosa host plants are dicots, but it has also been reported in monocots and ginkgo, a gymnosperm. However, the vast majority of host plants remain asymptomatic, making them reservoirs for infection.{{citation needed|date=November 2022}}

Due to the temperate climates of South America and the southeastern and west coast of the United States, X. fastidiosa can be a limiting factor in fruit crop production, particularly for stone fruits in northern Florida and grapes in California. In South America, X. fastidiosa can cause significant losses in the citrus and coffee industries; a third of today's citrus crops in Brazil has CVC symptoms.

X. fastidiosa also colonizes the foreguts of insect vectors,{{Cite journal |last1=Cornara |first1=Daniele |last2=Morente |first2=Marina |last3=Markheiser |first3=Anna |last4=Bodino |first4=Nicola |last5=Tsai |first5=Chi-Wei |last6=Fereres |first6=Alberto |last7=Redak |first7=Richard A. |last8=Perring |first8=Thomas M. |last9=Lopes |first9=Joao Roberto Spotti |date=2019-12-23 |title=An overview on the worldwide vectors of Xylella fastidiosa |url=http://www.schweizerbart.de/papers/entomologia/detail/39/91945/An_overview_on_the_worldwide_vectors_of_Xylella_fa?af=crossref |journal=Entomologia Generalis |language=en |volume=39 |issue=3–4 |pages=157–181 |doi=10.1127/entomologia/2019/0811 |issn=0171-8177}} which can be any xylem-feeding insects, often sharpshooters in the Cicadellidae subfamily Cicadellinae. After an insect acquires X. fastidiosa, it has a short latent period around 2 hours, then the bacterium is transmissible for a period of a few months or as long as the insect is alive.{{Cite journal |last1=Chatterjee |first1=Subhadeep |last2=Almeida |first2=Rodrigo P. P. |last3=Lindow |first3=Steven |date=2008-09-08 |title=Living in two Worlds: The Plant and Insect Lifestyles of Xylella fastidiosa |url=https://www.annualreviews.org/content/journals/10.1146/annurev.phyto.45.062806.094342 |journal=Annual Review of Phytopathology |language=en |volume=46 |issue= 1|pages=243–271 |doi=10.1146/annurev.phyto.45.062806.094342 |pmid=18422428 |bibcode=2008AnRvP..46..243C |issn=0066-4286}} The bacterium multiplies within its vectors, forming a "bacterial carpet" within the foregut of its host. If the host sheds its foregut during molting, the vector is no longer infected, but can reacquire the pathogen. At present, no evidence shows that the bacterium has any detrimental effect on its insect hosts.

The EFSA maintains a list of plants known to be susceptible to Xylella and updates it regularly. Classification is performed down to the subspecies level if possible. {{As of|2025|05}}, the latest report is from July 2024, containing information from literature published before 31 December 2023. The lists provided in EFSA's journal article about the update is only a summary; full data is available from the [https://www.efsa.europa.eu/en/microstrategy/xylella Microstrategy] platform of the EFSA.{{cite journal |last1=Cavalieri |first1=Vincenzo |last2=Fasanelli |first2=Elisa |last3=Gibin |first3=Davide |last4=Gutierrez Linares |first4=Alicia |last5=La Notte |first5=Pierfederico |last6=Pasinato |first6=Luca |last7=Delbianco |first7=Alice |title=Update of the Xylella spp. host plant database – Systematic literature search up to 31 December 2023 |journal=EFSA Journal |date=July 2024 |volume=22 |issue=7 |pages=e8898 |doi=10.2903/j.efsa.2024.8898|pmid=39010863 |pmc=11247332 }}{{cite journal | last1=Delbianco | first1=Alice | last2=Gibin | first2=Davide | last3=Pasinato | first3=Luca | last4=Morelli | first4=Massimiliano | title=Update of the Xylella spp. host plant database – systematic literature search up to 31 December 2020 | journal=EFSA Journal | publisher=European Food Safety Authority (Wiley) | volume=19 | issue=6 | year=2021 | pages=e06674 | issn=1831-4732 | doi=10.2903/j.efsa.2021.6674 | pmid=34188716 | pmc=8220458 | s2cid=235671792}}

Oleander leaf scorch is a disease of landscape oleanders (Nerium oleander) caused by a X. fastidiosa strain that has become prevalent in California and Arizona, starting in the mid-1990s. This disease is transmitted by a type of leafhopper (insect) called the glassy-winged sharpshooter (Homalodisca coagulata). Oleander is commonly used in decorative landscaping in California, so the plants serve as widely distributed reservoirs for Xylella.{{Cite journal |last1=Hernandez-Martinez |first1=Rufina |last2=de la Cerda |first2=Karla A. |last3=Costa |first3=Heather S. |last4=Cooksey |first4=Donald A. |last5=Wong |first5=Francis P. |date=July 2007 |title=Phylogenetic Relationships of Xylella fastidiosa Strains Isolated from Landscape Ornamentals in Southern California |url=https://apsjournals.apsnet.org/doi/10.1094/PHYTO-97-7-0857 |journal=Phytopathology |language=en |volume=97 |issue=7 |pages=857–864 |doi=10.1094/PHYTO-97-7-0857 |pmid=18943935 |bibcode=2007PhPat..97..857H |issn=0031-949X}}

Both almond and oleander plants in the Italian region of Apulia have also tested positive for the pathogen.

Pierce's disease (PD) was discovered in 1892{{cite book | title=The California Vine Disease: A Preliminary Report of Investigations | last=Pierce | first=Newton Barris | date=1892 | url=http://archive.org/details/californiavinedi02pier | isbn=978-1331970958 | location=Government Printing Office, Washington, DC US | oclc=4512989 | publisher=United States Department of Agriculture, Division of Vegetable Pathology | series=Bulletins | number=2}} {{isbn|1331970954}}. by Newton B. Pierce (1856–1916; California's first professional plant pathologist) on grapes in California near Anaheim, where it was known as "Anaheim disease".{{cite book|last1=Pinney|first1=Thomas|title=A History of Wine in America from the Beginnings to Prohibition|date=1989|publisher=University of California Press|isbn=978-0520062245|pages=[https://archive.org/details/historyofwineina0000pinn/page/27 27]|url=https://archive.org/details/historyofwineina0000pinn|url-access=registration}} The disease is endemic in Northern California, being spread by the blue-green sharpshooter, which attacks only grapevines adjacent to riparian habitats. It became a real threat to California's wine industry when the glassy-winged sharpshooter, native to the Southeast United States, was discovered in the Temecula Valley in California in 1996; it spreads PD much more extensively than other vectors.{{Cite journal |last1=Haviland |first1=David R |last2=Stone-Smith |first2=Beth |last3=Gonzalez |first3=Minerva |date=2021-01-01 |title=Control of Pierce's Disease Through Areawide Management of Glassy-Winged Sharpshooter (Hemiptera: Cicadellidae) and Roguing of Infected Grapevines |journal=Journal of Integrated Pest Management |volume=12 |issue=1 |doi=10.1093/jipm/pmab008 |issn=2155-7470|doi-access=free }}

When a grape vine becomes infected, the bacterium causes a gel to form in the xylem tissue of the vine, preventing water from being drawn through the vine.{{Cite web |last=Meyer |first=Brittnay |date=2018 |title=Pierce's Disease on grapes |url=https://plantclinic.tamu.edu/calendar2019/oleanderxylella/piercesdisease/ |access-date=2023-05-05 |website=Texas Plant Disease Diagnostic Lab}} Leaves on vines with Pierce's disease turn yellow and brown, and eventually drop off the vine. Shoots also die. After one to five years, the vine itself dies. The proximity of vineyards to citrus groves compounds the threat, because citrus is not only a host of sharpshooter eggs, but also is a popular overwintering site for this insect.{{Cite journal |last1=Pollard |first1=Herschel N. |last2=Kaloostian |first2=George H. |date=1961-08-01 |title=Overwintering Habits of Homalodisca coagulata, the Principal Natural Vector of Phony Peach Disease Virus |url=http://dx.doi.org/10.1093/jee/54.4.810 |journal=Journal of Economic Entomology |volume=54 |issue=4 |pages=810–811 |doi=10.1093/jee/54.4.810 |issn=1938-291X}}

In a unique effort, growers, administrators, policy makers, and researchers are working on a solution for this immense X. fastidiosa threat. No cure has been found,winepros.com.au. {{Cite web|last= Oxford Companion to Wine|title= Pierce's disease|url= http://www.winepros.com.au/jsp/cda/reference/oxford_entry.jsp?entry_id=2428|access-date= 2008-05-07|archive-date= 2008-08-08|archive-url= https://web.archive.org/web/20080808234742/http://www.winepros.com.au/jsp/cda/reference/oxford_entry.jsp?entry_id=2428|url-status= dead}} but the understanding of X. fastidiosa and glassy-winged sharpshooter biology has markedly increased since 2000, when the California Department of Food and Agriculture, in collaboration with different universities, such as University of California, Davis; University of California, Berkeley; University of California, Riverside, and University of Houston–Downtown started to focus their research on this pest. The research explores the different aspects of the disease propagation from the vector to the host plant and within the host plant, to the impact of the disease on California's economy. All researchers working on Pierce's disease meet annually in San Diego in mid-December to discuss the progress in their field. All proceedings from this symposium can be found on the Pierce's disease website,{{Cite web|last= PIPRA Pierce's Disease website| title= Pierce's disease |url= http://www.piercesdisease.org}} developed and managed by the Public Intellectual Property Resource for Agriculture (PIPRA).{{Cite web |last= |title=Public Intellectual Property Resource for Agriculture (PIPRA) |url=http://www.pipra.org |url-status=usurped |archive-url=https://web.archive.org/web/20160305041558/http://www.pipra.org/en/page/Default/index |archive-date=5 March 2016}}

Few resistant Vitis vinifera varieties are known, and Chardonnay and Pinot noir are especially susceptible, but muscadine grapes (V. rotundifolia) have a natural resistance. Pierce's disease is found in the Southeastern United States and Mexico. Also, it was reported by Luis G. Jiménez-Arias in Costa Rica, and Venezuela,{{cite journal|last=Jiménez A.|first=L.G.|title=Evidencia inmunológica del mal de pierce de la vid en Venezuela.|journal=Turrialba|date=July–September 1985|volume=35|issue=3|pages=243–247}} and possibly in other parts of Central and South America. In 2010, X. fastidiosa became apparent in Europe, posing a serious, real threat.{{Cite journal |last1=Janse |first1=J.D. |last2=Obradovic |first2=A. |date=2010 |title=Xylella Fastidiosa: ITS Biology, Diagnosis, Control and Risks |url=https://www.jstor.org/stable/41998754 |journal=Journal of Plant Pathology |volume=92 |pages=S35–S48 |issn=1125-4653 |jstor=41998754}} There are isolated hot spots of the disease near creeks in Napa and Sonoma in Northern California.

Work is underway at UC Davis to breed PD resistance from V. rotundifolia into V. vinifera. The first generation was 50% high-quality V. vinifera genes, the next 75%, the third 87% and the fourth 94%. In the spring of 2007, seedlings that are 94% V. vinifera were planted.[http://www.pdgwss.net/wp-content/uploads/2012/08/PD_Newsletter_Spring07.pdf PD/GWSS Board bulletin] {{Webarchive|url=https://web.archive.org/web/20150518083422/http://www.pdgwss.net/wp-content/uploads/2012/08/PD_Newsletter_Spring07.pdf |date=2015-05-18 }}, California Department of Food & Agriculture, Spring 2007 (p. 2)

A resistant variety, 'Victoria Red', was released for use especially in Coastal Texas.{{Cite journal |last1=Moore |first1=James N. |last2=Clark |first2=John R. |last3=Kamas |first3=James |last4=Stein |first4=Larry |last5=Tarkington |first5=Friench |last6=Tarkington |first6=Martha |date=2011-05-01 |title='Victoria Red' Grape |url=https://journals.ashs.org/hortsci/view/journals/hortsci/46/5/article-p817.xml |journal=HortScience |language=en |volume=46 |issue=5 |pages=817–820 |doi=10.21273/HORTSCI.46.5.817 |issn=0018-5345 |doi-access=free}}

The management of X. fastidiosa, a dangerous plant pathogen, requires a multidisciplinary approach that includes genetic and spatial ecology perspectives.{{Cite journal |last1=De La Fuente |first1=Leonardo |last2=Navas-Cortés |first2=Juan A. |last3=Landa |first3=Blanca B. |date=May 2024 |title=Ten Challenges to Understanding and Managing the Insect-Transmitted, Xylem-Limited Bacterial Pathogen Xylella fastidiosa |url=https://apsjournals.apsnet.org/doi/10.1094/PHYTO-12-23-0476-KC |journal=Phytopathology |volume=114 |issue=5 |pages=869–884 |doi=10.1094/PHYTO-12-23-0476-KC |pmid=38557216 |bibcode=2024PhPat.114..869D |issn=0031-949X}} Such an approach will improve knowledge on invasive processes and resource allocation, optimizing diagnostic and management efforts. Effective communication with stakeholders is crucial for successful and sustainable management. X. fastidiosa is a great way to study how pathogenicity changes at different levels of biological complexity. This will help scientists come up with better ways to find and control invasive species.

Image:OleanderLeafScorch.jpg infected with X. fastidiosa in Phoenix, Arizona]]

File:Olivenhain mit Xylella fastidiosa bei Surano LE 190710.jpg

In October 2013, the bacterium was found infecting olive trees in the region of Apulia in southern Italy.{{cite news |last=Kinver |first=Mark |date=9 January 2015 |title='Major consequences' if olive disease spreads across EU |url=https://www.bbc.co.uk/news/science-environment-30737754 |access-date=1 March 2015 |publisher=BBC News}} The disease caused rapid decline in olive grove yields, and by April 2015, was affecting the whole Province of Lecce and other zones of Apulia,{{cite web |last1=Spagnolo |first1=Chiara |date=2015-04-29 |title=Xylella, allarme nuovi focolai, per la Ue interessata tutta la Puglia |trans-title=Xylella, new outbreak alarm, for the EU all of Puglia affected |url=http://bari.repubblica.it/cronaca/2015/04/29/news/xylella_allarme_nuovi_focolai_il_piano_ue_mette_a_rischio_anche_il_vino_primitivo_-113127157/ |access-date=8 May 2015 |website=La Repubblica |language=it}} though it had not previously been confirmed in Europe.{{cite web|url=http://www.eppo.int/QUARANTINE/special_topics/Xylella_fastidiosa/Xylella_fastidiosa.htm|title=First report of Xylella fastidiosa in the EPPO region|publisher=European and Mediterranean Plant Protection Organization (EPPO)|access-date=1 March 2015}} The subspecies involved in Italy is X. f. subsp. pauca, which shows a marked preference for olive trees and warm conditions and is thought to be unlikely to spread to Northern Europe.{{cite web |url=https://planthealthportal.defra.gov.uk/pests-and-diseases/high-profile-pests-and-diseases/xylella/ |title=Xylella fastidiosa|work=Plant Health Portal |publisher=Department for Environment, Food and Rural Affairs |access-date=24 June 2017}}

The cycle in olives has been called olive quick decline syndrome (in {{langx|it|complesso del disseccamento rapido dell'olivo}}).{{cite news |last=Butler |first=Julie |date=29 March 2014 |title=Expert Says Eradication of New Olive Tree Disease in Europe Unlikely |url=http://www.oliveoiltimes.com/olive-oil-making-and-milling/expert-assesses-risk-posed-new-olive-tree-killer-europe/39158 |access-date=1 March 2015 |publisher=Olive Oil Times}} The disease causes withering and desiccation of terminal shoots, distributed randomly at first but then expanding to the rest of the canopy resulting in the collapse and death of trees. In affected groves, all plants normally show symptoms. The most severely affected olives are the century-old trees of local cultivars Cellina di Nardò and Ogliarola salentina.{{cite journal |title=Xylella fastidiosa in Olive in Apulia: Where We Stand|journal=Phytopathology |volume=109|issue=2|pages=175–186|publisher=American Phytopathological Society |doi=10.1094/PHYTO-08-18-0319-FI|pmid=30376439|year=2019|last1=Saponari|first1=M.|last2=Giampetruzzi|first2=A.|last3=Loconsole|first3=G.|last4=Boscia|first4=D.|last5=Saldarelli|first5=P.|doi-access=free|bibcode=2019PhPat.109..175S |hdl=11586/226511|hdl-access=free}}

By 2015, the disease had infected up to a million olive trees in Apulia{{cite news |last=Squires |first=Nick |date=27 February 2015 |title=Italy warns deadly olive tree bacteria could spread across Europe |url=https://www.telegraph.co.uk/news/worldnews/europe/italy/11440639/Italy-warns-deadly-olive-tree-bacteria-could-spread-across-Europe.html |access-date=1 March 2015 |publisher=The Telegraph}} and Xylella fastidiosa had reached Corsica,{{cite news| url=https://www.economist.com/blogs/graphicdetail/2015/07/daily-chart-hard-pressed | title= Olive oil dries up | date=31 July 2015| newspaper= The Economist| access-date=2015-07-31}} By October 2015, it had reached Mainland France, near Nice, in Provence-Alpes-Côte d'Azur, affecting the non-native myrtle-leaf milkwort (Polygala myrtifolia). This is the subspecies X. fastidiosa subsp. multiplex which is considered to be a different genetic variant of the bacterium to that found in Italy.{{cite web |url=https://ec.europa.eu/food/plant/plant_health_biosecurity/legislation/emergency_measures/xylella-fastidiosa_en |title=Xylella fastidiosa |work=Plants |publisher=European Commission |access-date=24 June 2017|date=2016-10-17 }}{{cite web |date=9 October 2015 |title=Un premier cas de la bactérie tueuse de végétaux découvert à Nice |trans-title=A first case of the plant killer bacterium discovered in Nice |url=http://www.nicematin.com/derniere-minute/un-premier-cas-de-la-bacterie-tueuse-de-vegetaux-decouvert-a-nice.2361861.html |access-date=2015-10-09 |work=Nice Matin |language=fr}} On 18 August 2016 in Corsica, 279 foci of the infection have been detected, concentrated mostly in the south and the west of the island.{{Cite web|title=Xylella : carte et liste des communes en zones délimitées en Corse au 18 août 2016|url=http://draaf.corse.agriculture.gouv.fr/Xylella-carte-et-liste-des,549|website=Direction régionale de l'alimentation, de l'agriculture et de la forêt de Corse|access-date=23 August 2016|language=fr|archive-date=23 August 2016|archive-url=https://web.archive.org/web/20160823204112/http://draaf.corse.agriculture.gouv.fr/Xylella-carte-et-liste-des,549|url-status=dead}} In August 2016, the bacterium was detected in Germany in an oleander plant.{{Cite news |last=Schröder |first=Elke |title=Pflanzen-Killerbakterium: Teile von Zeulenroda-Triebes zur Sperrzone erklärt |trans-title=Plant killer bacteria: Parts of Zeulenroda rails declared a restrict zone |url=http://www.antennethueringen.de/at/blog/pflanzen-killerbakterium-12242 |url-status=dead |archive-url=https://archive.today/20160827131558/http://www.antennethueringen.de/at/blog/pflanzen-killerbakterium-12242 |archive-date=August 27, 2016 |access-date=23 August 2016 |journal=Antenne Thueringen |language=de}} In January 2017 it was detected in Mallorca and Ibiza.{{Cite news |last=Elcacho |first=Joaquim |title=La plaga vegetal más peligrosa de Europa invade las Baleares |trans-title=Europe's most dangerous plant pest invades the Balearic Islands |url=http://www.lavanguardia.com/natural/20170124/413661628154/plaga-vegetal-xylella-fastidiosa-afecta-baleares.html |access-date=24 January 2017 |journal=La Vanguardia |language=es}}

Notably, in 2016, olive leaf scorch was first detected in X. fastidiosa{{'}}s native range, in Brazil.

In June 2017, it was detected in the Iberian peninsula, specifically in Guadalest, Alicante.{{Cite news |title=Tala preventiva de árboles ante el primer caso de 'Xylella fastidiosa' en la península |trans-title=Preventive tree lysing in the first case of Xylella fastidiosa on the peninsula |url=http://www.lavanguardia.com/natural/20170704/423893630061/tala-arboles-primer-brote-xylella-fastidiosa-peninsula-iberica.html |access-date=4 July 2017 |journal=La Vanguardia |language=es}} In 2018, it was detected elsewhere in Spain{{Cite news|title=Detectada en Madrid la presencia de una bacteria que obligó a arrancar un millón de olivos en Italia|url=https://www.20minutos.es/noticia/3310357/0/detectada-madrid-bacteria-olivos-vinedos-arboles-frutales/|journal=20 Minutos|access-date=12 April 2018|language=es}} and Portugal,{{Cite web|title=Xylella fastidiosa (XYLEFA) [Portugal]{{!}} EPPO Global Database|url=https://gd.eppo.int/taxon/XYLEFA/distribution/PT|access-date=2020-08-03|website=gd.eppo.int}} and in Israel in 2019.{{Cite web|title=Xylella fastidiosa (XYLEFA) [Israel]{{!}} EPPO Global Database|url=https://gd.eppo.int/taxon/XYLEFA/distribution/IL|access-date=2020-08-03|website=gd.eppo.int}}

Xylella infection was detected in South American citrus in the 1980s and subsequently in the USA but had limited spread beyond the Americas until the detection in citrus groves in Portugal in 2023.{{Cite web |last=NTC |first=À Punt |date=2023-01-11 |title=Portugal detecta la 'Xylella fastidiosa' en cítrics per primera vegada en la UE |trans-title=Portugal detects 'Xylella fastidiosa' in citrus fruits for the first time in the EU |url=https://www.apuntmedia.es/noticies/economia/portugal-detecta-xylella-fastidiosa-citrics-primera-vegada-ue_1_1582888.html |access-date=2023-01-20 |website=À Punt |language=ca}}

The genome of X. fastidiosa was sequenced in 2000 by a pool of over 30 research laboratories in the state of São Paulo, Brazil, funded by the São Paulo Research Foundation.{{Cite journal |last1=Simpson |first1=A. J. G. |last2=Reinach |first2=F. C. |last3=Arruda |first3=P. |last4=Abreu |first4=F. A. |last5=Acencio |first5=M. |last6=Alvarenga |first6=R. |last7=Alves |first7=L. M. C. |last8=Araya |first8=J. E. |last9=Baia |first9=G. S. |last10=Baptista |first10=C. S. |last11=Barros |first11=M. H. |last12=Bonaccorsi |first12=E. D. |last13=Bordin |first13=S. |last14=Bové |first14=J. M. |last15=Briones |first15=M. R. S. |date=2000 |title=The genome sequence of the plant pathogen Xylella fastidiosa |journal=Nature |language=en |volume=406 |issue=6792 |pages=151–157 |bibcode=2000Natur.406..151S |doi=10.1038/35018003 |issn=1476-4687 |pmid=10910347 |doi-access=free}}

• Bacterial leaf scorch
• Homalodisca vitripennis
• Philaenus spumarius

{{Reflist}}

{{refbegin}}

• {{Cite web|url=http://piercesdisease.cdfa.ca.gov/|title=CDFA - Pierce's Disease Research Updates|website=piercesdisease.cdfa.ca.gov|access-date=2020-02-15}}
• {{Cite web|url=http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_phglassy.html|title=Glassy-winged Sharpshooter and Pierce's Disease in California|date=December 2002|url-status=dead|archive-url=https://web.archive.org/web/20060509013325/http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_phglassy.html|archive-date=2006-05-09|access-date=2020-02-15}}
• CDFA PD/GWSS Board Website [http://pdgwss.net PD/GWSS Interactive Forum]
• {{Cite web|url=http://cals.arizona.edu/PLP/plpext/diseases/trees/oleander/oleleaf.htm|title=Oleander leaf scorch|date=July 10, 2006|url-status=dead|archive-url=https://web.archive.org/web/20060918024548/http://cals.arizona.edu/PLP/plpext/diseases/trees/oleander/oleleaf.htm|archive-date=2006-09-18|access-date=2020-02-15}}
• {{Cite journal|last1=Wells|first1=J. M.|last2=Raju|first2=B. C.|last3=Hung|first3=H.-Y.|last4=Weisburg|first4=W. G.|last5=Mandelco-Paul|first5=L.|last6=Brenner|first6=D. J.|date=1987-04-01|title=Xylella fastidiosa gen. nov., sp. nov: Gram-Negative, Xylem-Limited, Fastidious Plant Bacteria Related to Xanthomonas spp.|journal=International Journal of Systematic Bacteriology|language=en|volume=37|issue=2|pages=136–143|doi=10.1099/00207713-37-2-136|issn=0020-7713|doi-access=free}}
• {{cite journal|last=Catalano |first=Luigi|year=2015|title=Xylella fastidiosa la più grave minaccia dell'olivicoltura italiana|journal=L'Informatore Agrario|pages=36–42|archive-url=https://web.archive.org/web/20180618203803/http://www.informatoreagrario.it/ita/files/Emergenza_Xylella.pdf|archive-date=2018-06-18|access-date=2020-02-15|issue=16|language=it|url=http://www.informatoreagrario.it/ita/files/Emergenza_Xylella.pdf|url-status=dead}}

{{refend}}

{{Scholia|topic}}

• [http://bacdive.dsmz.de/index.php?search=17622&submit=Search Type strain of Xylella fastidiosa at BacDive - the Bacterial Diversity Metadatabase]
• {{cite web | title=XF-ACTORS | website=XF-ACTORS (Xylella Fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy) | date=2021-02-02 | url=http://www.xfactorsproject.eu/ | access-date=2021-03-30}}
• {{cite web | title=XF-ACTORS "Xylella Fastidiosa Active Containment Through a multidisciplinary-Oriented Research" | website=EIP-AGRI - European Commission | date=2017-08-30 | url=http://ec.europa.eu/eip/agriculture/en/find-connect/projects/xf-actors-xylella-fastidiosa-active-containment | access-date=2021-03-30}}

{{Viticulture}}

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{{Authority control}}

Category:Bacteria described in 1987

Category:Bacterial grape diseases

Category:Bacterial citrus diseases

Category:Bacterial plant pathogens and diseases

Category:Xanthomonadales