Editing Fire blight (section)

==Pathogenesis==
Pathogenicity depends on many different factors such as the production of the siderophore desferrioxamine, metalloproteases, plasmids, and histone-like proteins. However, some essential factors of pathogenicity are variations in the synthesis of extracellular polysaccharides (EPS) and the mechanism of type III secretion system and its associated proteins.<ref>{{cite journal |last1=Piqué |first1=Núria |last2=Miñana-Galbis |first2=David |last3=Merino |first3=Susana |last4=Tomás |first4=Juan |title=Virulence Factors of ''Erwinia amylovora'': A Review |journal=International Journal of Molecular Sciences |date=5 June 2015 |volume=16 |issue=12 |pages=12836–12854 |doi=10.3390/ijms160612836 |pmid=26057748 |pmc=4490474 |hdl=2445/67259 |doi-access=free}}</ref> EPS helps bacterial pathogens avoid plant defenses, “clog” the host's vascular system, protect bacteria against desiccation and attach to both surfaces and one another. One EPS is [[amylovoran]], a polymer of pentasaccharide repeating units. If a strain of ''E. amylovora'' cannot produce amylovoran it will not be pathogenic and will be unable to spread in plants. [[Levan (polysaccharide)|Levan]] is another EPS, and a lack of it will slow development of symptoms. Type III secretion systems are used for exporting and delivering effector proteins into the cytosol of host plants. This system mainly consists of Hrc proteins. Motility is another major virulence factor.<ref>{{cite journal |last1=Vrancken |first1=K. |last2=Holtappels |first2=M. |last3=Schoofs |first3=H. |last4=Deckers |first4=T. |last5=Valcke |first5=R. |title=Pathogenicity and infection strategies of the fire blight pathogen Erwinia amylovora in Rosaceae: State of the art |journal=Microbiology |date=1 May 2013 |volume=159 |issue=5 |pages=823–832 |doi=10.1099/mic.0.064881-0 |pmid=23493063 |s2cid=10127630|doi-access=free }}</ref> Since ''E. amylovora'' is not an obligate biotroph, it is able to survive outside the host. This fact allows the organism to be spread by such a variety if methods.{{citation needed|date=November 2022}}