Bacteriophage Control of Pseudomonas savastanoi pv. glycinea in Soybean

Abstract

Bacterial viruses (bacteriophages) have been considered as potential agents for the biological control of bacterial phytopathogens due to their safety and host specificity. Pseudomonas savastanoi pv. glycinea (Psg) is a causative agent of the bacterial spotting of soybean (Glycine max Willd). The harm caused by this bacterium to crop production and the development of antibiotic resistance in Psg and other pathogenic microorganisms has led to the pursuit of alternative management strategies. In this study, three Psg-specific lytic bacteriophages were isolated from soybean field soil in geographically distant regions of Russia, and their potential for protective action on plants was assessed. Sequencing of phage genomes has revealed their close relatedness and attribution to the genus Ghunavirus, subfamily Studiervirinae, family Autographiviridae. Extensive testing of the biological properties of P421, the representative of the isolated phage group, has demonstrated a relatively broad host range covering closely related Pseudomonas species and stability over wide temperature (4–40 °C) and pH (pH 4–7) ranges, as well as stability under ultraviolet irradiation for 30 min. Application of the phages to prevent, and treat, Psg infection of soybean plants confirms that they are promising as biocontrol agents.

Using of Essential Oils and Plant Extracts against Pseudomonas savastanoi pv. glycinea and Curtobacterium flaccumfaciens pv. flaccumfaciens on Soybean

“…The relevance and repeatability of models of artificial infections Psg and Cff on soybean plants was described in detail in our previous studies and the experimental conditions were identical to those described earlier in Refs. [ 22 , 23 ].…”

“…glycinea CFBP 2214 and Curtobacterium flaccumfaciens pv. flaccumfaciens CFBP 3418 from the CFBP collection (Beaucouzé, France) and Russian strains isolated (from damaged by diseases soybean plants in 2019–2021 years) and described by us (Psg: G2 and G17, Cff: F-125-1 and F-30-1) in previous publications [ 22 , 80 ]. These strains were pathogenic against soybean plants cv.…”

“…The creation of an artificial infection Psg on seeds was carried out according to the method [ 22 ]. Briefly, 72 h culture of Psg CFBP 2214 was resuspended in sterile 10 mM MgCl 2 to ~10 4 CFU/mL.…”

“…Unfortunately, their permanent use leads to the development of resistance in bacteria so it is limited in many countries (including Russia), while copper preparations are not effective enough [ 18 ], accumulate in plants and soil, and cause environmental problems [ 19 ]. There are attempts to use biological agents: antagonistic bacteria [ 20 ], PGPR [ 21 ], and bacteriophages [ 22 , 23 ] to control the pathogens, but the effectiveness of bioagents depends on the conditions of their use.…”

Isolation of Novel Xanthomonas Phages Infecting the Plant Pathogens X. translucens and X. campestris

“…Erwinia amylovora , which developed resistance to streptomycin, has led to the evaluation of phage biocontrol with promising outcomes in some cases [ 14 , 15 , 16 ]. Due to the broad spectrum of plants infected by Pseudomonas syringae spp., multiple biocontrol trails have been conducted in the past, but with a special effort on citrus canker disease [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Xylella fastidiosa is a major threat to olive trees in Europe, where first phages have been isolated and tested [ 24 , 25 , 26 ].…”