Isolation of <italic>Dickeya dadantii</italic> strains from potato disease and biocontrol by their bacteriophages

Abstract

One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains.

Newly Isolated Bacteriophages from the Podoviridae, Siphoviridae, and Myoviridae Families Have Variable Effects on Putative Novel Dickeya spp.

“…All the bacteriophages active against Dickeya spp. described in the literature belong to the order Caudovirales as members of the Myoviridae family ( Adriaenssens et al, 2012 ; Czajkowski et al, 2014 , 2015 ; Soleimani-Delfan et al, 2015 ), and the first report about a bacteriophage from the Siphoviridae family was made recently ( Soleimani-Delfan et al, 2015 ). However, the present study represents the first report of bacteriophages active against Dickeya spp.…”

“…Their effectiveness was tested in vitro , and they showed promising biocontrol potential. However, no field trials have been conducted to date ( Soleimani-Delfan et al, 2015 ).…”

Pectobacterium brasiliense: Genomics, Host Range and Disease Management

“…In vitro experiments performed by Czajkowski et al [ 134 , 135 ] reported successful suppression of disease symptoms caused by D. solani , P. carotovorum and P. wasabiae on potato tubers. Soleimani-Delfan et al [ 157 ] reported the isolation of two bacteriophages from the Caspian Sea active against D. dadanti (the causative agent of potato soft rot in Iran), which reduced rot when inoculated onto Geranium spp. by approximately 89% in comparison to the positive control.…”

Characterization of blackleg and soft rot from potato in northern Thailand

“…brasiliense based on 16S rDNA sequences. Soleimani‐Delfan, Etemadifar, Bouzari, Emtiazi, and Bouzari () found that the bacterium that caused soft rot disease in tubers and other plant parts of members of the Solanaceae family was D. dadantii strains pis3 and sip4 in Isfahan Province, Iran. They were identified by biochemical tests and tested positive for catalase activity and gelatin hydrolysis but negative for urease.…”