Location: Emerging Pests and Pathogens ResearchTitle: Distinct transcriptional regulators contribute to growth of Dickeya dadantii and D. dianthicola in potato tubers
Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/2021
Publication Date: 8/5/2021
Citation: Helmann, T.C., Filiatrault, M.J., Stodghill, P. 2021. Distinct transcriptional regulators contribute to growth of Dickeya dadantii and D. dianthicola in potato tubers. American Phytopathological Society. https://www.aps.org/publications/apsnews/202102/march.cfm.
Technical Abstract: Members of the Soft Rot Pectobacteriaceae (Dickeya and Pectobacterium spp.) are highly damaging to a wide range of crops. These closely-related pathogens share many important virulence traits, such as the production of plant cell wall degrading enzymes. However, as there has been little host-specificity observed for the soft rot pathogens, it is unclear the extent to which virulence traits may vary among strains. To functionally annotate virulence determinants and host colonization traits, we constructed and mapped large (>300,000 mutants) barcoded transposon libraries in the strains D. dadantii 3937, D. dianthicola ME23, and D. dianthicola 67-19. Changes in relative proportion of each mutant within a mixture enable fitness quantification of nearly all non-essential genes in that strain. By inoculating these transposon libraries into potato tubers, we identified genes that contribute to host colonization. Combined with a matrix of homologous gene families among these strains, generated using the PyParanoid computational pipeline, we can directly compare fitness traits in each strain. For example, we identified five putative DNA-binding transcriptional regulators whose presence is significantly detrimental to in planta fitness in a subset of strains. For further characterization of these putative regulators, we aim to identify members of each regulon as well as their distribution within the Dickeya and Pectobacterium pangenome. Species mixtures are often observed in soft rot, and so understanding of specific virulence traits is crucial for developing disease control methods.