Multiomics Analyses Reveal the Complexity of Interaction between Two Strains of Magnaporthe oryzae

Plants growing in open environments are frequently coinfected by multiple strains of the same pathogen. However, few investigations have been carried out to reveal the outcomes and underlying mechanisms of such infections. This study aimed to observe the behaviors of two different strains under coinfection and cocultivation. We constructed an experimental system to study such interactions directly by labeling Magnaporthe oryzae strains with the green fluorescent proteins and mushroom cherry fluorescent protein to observe mixed strain behavior in vivo and in vitro. Moreover, multiomics analyses were conducted to explore the underlying mechanisms at the genomic, transcriptomic, and metabolomic levels. Our results revealed that coinfection with two strains can affect disease severity and that the more weakly virulent strain benefits from the coinfection system. We also found that amino acid variation might negatively influence such interactions at transcriptomic and metabolomic levels. In addition, we showed that the overexpression of a glutamine-related gene improved strain competitiveness during mixture cultivation. Collectively, our results provided experimental methods to analyze the interaction between two strains of M. oryzae and preliminarily explored the interacted mechanism of two strains under cocultivation through multiomics analyses.