Project description:Lytic bacteriophages able to infect and kill Dickeya spp. can be readily isolated from virtually all Dickeya spp.-containing environments, yet little is known about the selective pressure those viruses exert on their hosts. Here, we identified two spontaneous phage-resistant D. solani IPO 2222 mutants, DsR34 and DsR207, resistant to infection caused by phage vB_Dsol_D5 (ΦD5) that expressed a reduced ability to macerate potato tuber tissues compared to the wild-type, phage-susceptible D. solani IPO 2222 strain. Genome sequencing revealed that mutants had point mutations in two genes encoding: secretion protein HlyD (mutant DsR34) and elongation factor Tu (EF-Tu) (mutant DsR207). Both mutations impacted the proteoms of D. solani grown in rich and minimal media. Furthermore, DsR34 and DsR207 were characterized for features essential for their ecological success in a plant environment, including the ability to use various carbon and nitrogen sources, production of plant cell wall degrading enzymes, ability to form biofilms, siderophore production, swimming and swarming motility and virulence in planta. Compared to the wild-type ΦD5-susceptible D. solani strain, mutants DsR34 and DsR207 expressed reduced ability to macerate chicory leaves and to colonize and cause symptoms in growing potato plants. The implications of the ΦD5 resistance on the ecological performance of D. solani are discussed.
Project description:Priestia endophytica FH5, which was isolated from healthy tomato rhizosphere soil, had biological activity against a variety of plant diseases, including R. solani. We isolated the chemicals generated by strain FH5 to better understand the interaction between strain FH5 and R. solani. A transcriptome study of strain FH5 with and without R. solani exposure was also performed. In response to the fungal pathogen R. solani, strain FH5 changed genes linked to amino acid transport, carbohydrate transport, energy generation and conversion, and inorganic ion transport and metabolism, according to our findings.
