Phyloproteomic study by MALDI-TOF MS in view of intraspecies variation in a significant homogenous phytopathogen Dickeya solani

Abstract

Dickeya solani is an economically significant pectinolytic phytopathogen belonging to the Pectobacteriaceae family, which causes soft rot and blackleg diseases. Despite its notable impact on global potato production, there are no effective methods to control this pest. Here, we undertook a phyloproteomic study on 20 D. solani strains, of various origin and year of isolation, with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) supported by an in-depth characterization of the strains in terms of the virulence-associated phenotype. In spite of high homogeneity in this species, we herein revealed for the first time intraspecies variation in the MALDI-TOF MS protein profiles among the studied D. solani isolates. Finally, representative mass spectra for the four delineated clades are presented. A majority of the analysed D. solani strains showed high virulence potential, while two strains stood out in their growth dynamics, virulence factors production and ability to macerate plant tissue. Nonetheless, the metabolic profiles of D. solani strains turned out to be uniform, except for gelatinase activity. Given that all D. solani isolates distinctly grouped from the other Dickeya species in the MALDI-TOF MS analysis, there is strong evidence supporting the potential routine use of this method for fast and reliable to-species identification of D. solani isolates of environmental origin.

Clonality and Diversity in the Soft Rot Dickeya solani Phytopathogen

“…These strains were grouped into four delineated clades and differed also in growth rate, plant tissue macerating potential and protease activities, in contrast to the high uniformity among the metabolic profiles, which diverged only in terms of gelatinase activity. However, a definitive link between pathogenicity and the recorded MALDI-TOF MS spectra could not be established [19].…”