Early phyllosphere remodeling in maize after herbivory uncovers candidate insecticidal bacteria from feeding-altered...

The "cry for help" hypothesis suggests that herbivore-stressed plants reshape their microbiome for defense, yet the speed and systemic characteristics of the phyllosphere bacterial response to chewing herbivores remain poorly understood. To address this, we examined how larval feeding by fall armyworm (Spodoptera frugiperda) affects the phyllosphere bacterial community within undamaged maize (Zea mays) leaves. We combined 16S amplicon sequencing, culturomics, and machine learning to characterize microbial community dynamics and culture-dependent recover candidate biocontrol strains from herbivory-altered taxa. Localized larval feeding on a single leaf induced rapid changes in the phyllosphere bacterial community of distal undamaged leaves within 12 h. Herbivory modified bacterial cooccurrence network topology. A significantly enriched OTU7 was isolated and identified as Enterobacter strain P12A2, which exhibited high toxicity against S. frugiperda. This study indicates that herbivory-induced systemic changes in the phyllosphere bacterial community of undamaged leaves may serve as a source for identifying novel biological resources. These findings provide a promising basis for developing microbiome-based strategies for sustainable pest management.