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

• Published in: Journal of chemical ecology Vol. 47; no. 2; pp. 227 - 241
• Main Authors: Mazumdar, Tilottama, Teh, Beng Soon, Murali, Aishwarya, Schmidt-Heck, Wolfgang, Schlenker, Yvonne, Vogel, Heiko, Boland, Wilhelm
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2021; Springer Nature B.V
• Subjects: Agriculture; Amino acids; bacterial communities; Biochemistry; biofilm; Biofilms; Biological Microscopy; Biomedical and Life Sciences; chemical ecology; Ecology; Enterococcus mundtii; Entomology; Fatty acids; Flow cytometry; Fluorescence; Gene sequencing; Hindgut; Insects; Intestinal microflora; intestinal microorganisms; Larvae; Life cycles; Life Sciences; Lysine; Metabolic pathways; Microorganisms; Oxidative stress; Quorum sensing; Ribonucleic acid; RNA; sequence analysis; Signalling systems; Spodoptera littoralis; Survival; Symbionts; Symbiosis; transcriptomics; Flow cytometry; Transcriptomics; Hindgut; Foregut; Enterococcus mundtii; Spodoptera littoralis
• ISSN: 0098-0331; 1573-1561; 1573-1561
• DOI: 10.1007/s10886-021-01246-1

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