Microbiome responses to naturalFusariuminfection in field-grown soybean plants

The rhizosphere microbiome influences plant health by mediating plant-pathogen interactions. Plants can recruit protective microbes in response to disease, but the consistency of this process in field conditions is unclear. We examined the rhizosphere microbiome of field-grown soybean (Glycine maxL.) naturally infected with root pathogens across three commercial fields in Kentucky, USA. Symptomatic and asymptomatic plants were sampled to assess disease-associated shifts in the rhizosphere microbiome. Amplicon sequencing identified a diverseFusariumcommunity, with oneFusarium solaniamplicon sequence variant (ASV) consistently enriched in diseased plants, identifying it as the likely pathogen. While microbial communities differed between diseased and healthy plants, these shifts were largely field-specific. Several fungal ASVs with known biocontrol potential (Clonostachys rosea, Penicillium, andTrichoderma) were enriched in healthy plants, implying a role in disease suppression. ASphingomonasASV, a genus previously linked to plant protection, was more abundant in diseased plant rhizospheres in two fields, suggesting pathogen-triggered recruitment. Conversely,Macrophomina phaseolina, a generalist root pathogen, was enriched in the rhizosphere of diseased plants in all fields, indicating possible co-infection withF. solani. These findings reveal complex pathogen-microbe interactions in field conditions and emphasize the need for field-specific microbiome research to inform sustainable disease management strategies.