Widespread Transcriptional Impacts of prophage within the rhizobia-legume symbiosis

Prophages – viruses that infect and integrate into bacterial chromosomes - can have important effects for their bacterial hosts. Here, we investigate the impact of carrying a prophage on the nitrogen-fixing symbiont, rhizobia. Rhizobia form symbioses with legumes in the form of root nodules. Their nitrogen-fixing ability has an important role in the transition to sustainable agriculture, potentially reducing the use of inorganic fertilisers. In this study, we show that prophage, vTRX32-1, has different effects on gene expression across two Rhizobium strains while in symbiosis with clover. Yet, phage presence does not affect the performance of the rhizobia-clover symbiosis. These results suggest that despite the potential impacts of prophage carriage on symbiont function, the symbiotic quality of lysogens is not significantly compromised.