Abstract
Dickeya species are economically important phytopathogens widespread in mainland Europe that can reduce crop yields by 25%. There are no effective environmentally-acceptable chemical systems available for diseases caused by Dickeya. Bacteriophages have been suggested for use in biocontrol of these pathogens in the field, and limited field trials have been conducted. To date the majority of bacteriophages capable of infecting Dickeya solani, one of the more aggressive species, are from the same family, the Ackermannviridae, many representatives of which have been shown to be unsuitable for use in the field due to their capacity for generalized transduction. Members of this family are also only capable of forming individual plaques on D. solani. Here we describe novel bacteriophages from environmental sources isolated on D. solani, including members of two other viral families; Myoviridae and Podoviridae, most of which are capable of forming plaques on multiple Dickeya species. Full genomic sequencing revealed that the Myoviridae family members form two novel clusters of jumbo bacteriophages with genomes over 250 kbp, with one cluster containing phages of another phytopathogen Erwinia amylovora. Transduction experiments showed that the majority of the new environmental bacteriophages are also capable of facilitating efficient horizontal gene transfer, however the single Podoviridae family member is not. This particular phage therefore has potential for use as a biocontrol agent against multiple species of Dickeya.
Highlights
The genus Dickeya, recently reclassified into the novel family Pectobacteriaceae (Adeolu et al, 2016), currently consists of 11 phytopathogenic species that can cause severe disease in economically important crops including tomato, orchid, and potato (Alic et al, 2017a)
It is currently yet to become established in the UK, and to mitigate the significant economic cost inflicted by this virulent phytopathogen, the Scottish government has introduced specific legislation aimed at preventing the establishment of D. solani in its seed industry (Mansfield et al, 2012)
The plaques of the previously described D. solani phages that are members of the Ackermannviridae family have tended to be clear, defined, and easy to distinguish from the bacterial top lawn (Adriaenssens et al, 2012c; Czajkowski et al, 2015a)
Summary
The genus Dickeya, recently reclassified into the novel family Pectobacteriaceae (Adeolu et al, 2016), currently consists of 11 phytopathogenic species that can cause severe disease in economically important crops including tomato, orchid, and potato (Alic et al, 2017a). In 2008/2009, a new clade of Dickeya in European potato isolates was identified (Laurila et al, 2008; Parkinson et al, 2009; Sławiak et al, 2009) and in 2014 a new species was proposed; Dickeya solani (van der Wolf et al, 2014). Dickeya solani is able to spread more through the plant vascular system and survive at higher temperatures than D. dianthicola (Toth et al, 2011). It is currently the predominant potato pathogen in Europe, with reductions in yield of up to 25% reported in potatoes exposed to Dickeya species (Tsror et al, 2009). It is currently yet to become established in the UK, and to mitigate the significant economic cost inflicted by this virulent phytopathogen, the Scottish government has introduced specific legislation aimed at preventing the establishment of D. solani in its seed industry (Mansfield et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
