Meeting Abstract

86.1  Monday, Jan. 6 10:00  Gut microbes mediate plant-animal interactions with respect to dietary toxins KOHL, K.D.*; WEISS, R.B.; COX, J.; DALE, D.; DEARING, M.D.; Univ. of Utah; Univ. of Utah; Univ. of Utah; Univ. of Utah; Univ. of Utah kkohl78@gmail.com

The foraging ecology of mammalian herbivores is strongly shaped by plant secondary compounds (PSCs) that act to defend plants against herbivory. Nearly forty years ago, ecologists Freeland and Janzen hypothesized that gut microbes allow animals to feed on toxic plants. However, this hypothesis has not been tested in a wild herbivore feeding on a complex of PSCs. We investigated the gut microbiota of the desert woodrat (Neotoma lepida), some populations of which specialize on highly toxic creosote bush (Larrea tridentata). We demonstrated that the gut microbiota is critical in allowing herbivores to feed on toxic plants. The foregut microbiota exhibited an increased abundance of genes associated with the metabolism of toxic compounds when woodrats were fed creosote PSCs. Treatment with a broad-spectrum antibiotic decreased the ability of woodrats to ingest creosote bush. In addition, natural populations of N. lepida that had no prior experience with creosote bush and are thus naïve to its PSCs, exhibited increased toxin tolerance when inoculated with microbes from experienced individuals. These animals eliminated creosote PSCs through unique detoxification routes as determined by metabolomic analysis of the urine. These results demonstrate that microbes can enhance host tolerance to PSCs and thus, potentially expand the dietary niche breadth of wild mammalian herbivores. Furthermore, microbial transfers represent a mechanism by which wild herbivores may rapidly adapt to novel and more potent PSCs brought about by environmental changes.