Transcriptomics Reveal the Survival Strategies of Enterococcus mundtii in the Gut of Spodoptera littoralis

The complex interaction between a higher organism and its resident gut flora is subject of immense interest in the field symbiosis. Many insects harbor community microorganisms their gut. Larvae Spodoptera littoralis, lepidopteran pest, house bacterial that varies both spatially (along length gut) temporally (during insect’s life cycle). To monitor rapid adaptation microbes to conditions gut, GFP-tagged reporter strain E. mundtii, major player community, was constructed. After early-instar S. littoralis larvae were fed with tagged microbes, these recovered from larval fore- hindgut by flow cytometry. fluorescent confirmed persistence mundtii RNA-sequencing sorted bacteria highlighted various strategies symbiont’s survival, including upregulated pathways for tolerating alkaline stress, forming biofilms two-component signaling systems quorum sensing, resisting oxidative stress. Although symbionts depend on host amino acid fatty acids, differential regulation among metabolic points an enriched lysine synthesis pathway larvae.