Data_Sheet_1_Jumbo Bacteriophages Are Represented Within an Increasing Diversity of Environmental Viruses Infecting the Emerging Phytopathogen, Dickeya solani.PDF

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.

迪基氏菌属（Dickeya）物种是具有重要经济价值的植物病原菌，广泛分布于欧洲大陆，可造成最高达25%的作物减产。目前尚无针对迪基氏菌引发病害的有效环境友好型化学防治手段。此前已有研究提出利用噬菌体（bacteriophages）对这类病原菌开展田间生物防治，并已完成有限的田间试验。截至目前，能够侵染致病力较强的物种之一——索氏迪基氏菌（Dickeya solani）的多数噬菌体均隶属于阿克曼噬菌体科（Ackermannviridae），且已有研究证实该科的多数毒株因具备普遍性转导能力而不适用于田间应用。此外，该科噬菌体仅能在索氏迪基氏菌上形成单个噬菌斑。本研究描述了从环境样本中分离得到的新型索氏迪基氏菌侵染性噬菌体，其中包含隶属于另外两个病毒科的毒株：肌尾噬菌体科（Myoviridae）和短尾噬菌体科（Podoviridae），其中大多数毒株能够在多种迪基氏菌属物种上形成噬菌斑。全基因组测序结果显示，肌尾噬菌体科成员可划分为两个新型巨型噬菌体（jumbo bacteriophages）簇，其基因组长度均超过250 kbp，其中一个簇的噬菌体还可侵染另一种植物病原菌火疫欧文氏菌（Erwinia amylovora）。转导实验结果表明，多数新型环境噬菌体同样能够介导高效的水平基因转移，而仅有的一株短尾噬菌体科成员则不具备该能力。因此，这株特殊的噬菌体具备作为针对多种迪基氏菌属物种的生物防治剂的应用潜力。