The microbes inhabiting plants have a significant impact on a variety of host functions, including growth and reproduction. Despite playing a pivotal role in nutrient cycling in boreal and temperate forests, we know surprisingly little about how mosses interact with their microbiota. Past studies from our lab have demonstrated that for some dioecious species, male and female mosses differ in their composition and quantity of tissue-colonizing fungi. Furthermore, female mosses generate volatile organic compounds (VOCs) that are more attractive to fungivorous springtails than male mosses, which reinforces male-to-female sperm transfer. Using the cosmopolitan, dioecious moss species, Ceratodon purpureus, we sought to answer the following questions: (1) Does the presence or absence of a complex microbial community have a differential impact on the sexual reproduction and growth of male and female mosses? (2) Does micro-arthropod preference for female mosses compared to male mosses change when a complex microbial community is absent? We raised axenic male and female C. purpureus genotypes in a controlled environment and inoculated plants with microbes extracted from a natural C. purpureus population. We measured moss growth, followed by direct choice assays to assess white springtail (Folsomia candida) preference for inoculated and non-inoculated male and female C. purpureus.
Results/Conclusions
Our preliminary results suggest that F. candida prefers female C. purpureus over male conspecifics whether mosses are inoculated or non-inoculated. When springtails were presented with inoculated and non-inoculated plants of the same sex, they preferred inoculated mosses in females, yet non-inoculated mosses mosses in males. These results indicate that springtail preference may be determined more by chemical cues produced by the moss than its associated microbes, yet more work is needed to evaluate whether the VOC profiles are different between inoculated and non-inoculated C. purpureus. Studying the effects of the moss microbiome on micro-arthropod recruitment can provide insights into trophic interactions occurring in the bryosphere.