ScholarWorks@성균관대학교

초록

Gut microbiota influence the expression of traits during host growth and development, and are increasingly recognized as the critical driver of host fitness. However, their role in the host's inducible anti-predator defense in response to predation pressure remains unclear. Here, we investigated how the assembly of the early-life gut microbiota affects the induced anti-predation morphological, behavioral, and life-history defenses of Daphnia magna. The results show that different types of bacterial inoculations specifically altered the gut microbial community of D. magna and further mediated the differential expression of its morphological and life-history defenses, rather than behavioral defenses, to cope with subsequent predation risk. Specifically, early life inoculation with probiotics such as Escherichia coli significantly enhanced the reproductive output and spine length of D. magna under subsequent predation risk, whereas early life inoculation with pathogenic bacteria such as Aeromonas hydrophila significantly reduced the body size, spine length, and reproductive output of D. magna under subsequent predation risk. Behavioral defense, that is, negative phototaxis, did not exhibit significant variation due to changes in the gut microbiota. Furthermore, the growth-survival trade-off of D. magna under predation risk may be mediated by specific bacteria present in its gut microbiota, such as Staphylococcus. These results reveal the role of the gut microbiota in shaping prey defenses and deepen our understanding of host-microbiota co-adaptation to complex environmental stressors.

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