Molecular mechanisms of persistence of mutualistic bacteria Photorhabdus in the entomopathogenic nematode host

• Published in: PloS one 2010-10, Vol.5 (10), p.e13154
• Main Authors: An, Ruisheng, Grewal, Parwinder S
• Format: Article
• Language: English
• Subjects: Acidification; Adaptation; Amino acids; Animals; Aspergillus nidulans; Bacteria; Base Sequence; Biofilms; Biosynthesis; Brachionus plicatilis; DNA Primers; Enterobacteriaceae - genetics; Enterobacteriaceae - growth & development; Enterobacteriaceae - physiology; Entomopathogenic nematodes; Gene expression; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genomes; Hemolymph; Heterorhabditis; Heterorhabditis bacteriophora; Hostages; Insects; Intestine; Lingulodinium; Metabolism; Metabolites; Microbiology; Microbiology/Applied Microbiology; Microbiology/Environmental Microbiology; Microbiology/Microbial Evolution and Genomics; Microbiology/Microbial Growth and Development; Microbiology/Microbial Physiology and Metabolism; Microorganisms; Molecular Biology; Molecular modelling; Motility; Mycobacterium avium; Mycobacterium tuberculosis; Nematoda; Nematoda - microbiology; Nutrition; Oxidative stress; Parasitic diseases; Pentose phosphate pathway; Phosphates; Photorhabdus; Photorhabdus temperata; Reverse Transcriptase Polymerase Chain Reaction; Roundworms; Signal transduction; Starvation; Steinernema; Symbiosis; Transcription; Tuberculosis
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0013154

Symbioses between microbes and animals are ubiquitous, yet little is known about the intricate mechanisms maintaining such associations. In an emerging mutualistic model system, insect-pathogenic bacteria Photorhabdus and their insect-parasitic nematode partner Heterorhabditis, we found that the bacteria undergo major transcriptional reshaping in the nematode intestine. Besides general starvation mechanisms, the bacteria induce cellular acidification to slow down growth, switch to pentose phosphate pathway to overcome oxidative stress and nutrition limitation, and shed motility but develop biofilm to persist in the nematode intestine until being released into the insect hemolymph. These findings demonstrate how the symbiotic bacteria reduce their nutritional dependence on the enduring nematode partner to ensure successful transmission of the couple to the next insect host.