caa a22 4500 605514259 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00360-015-0890-z doi (NATIONALLICENCE)springer-10.1007/s00360-015-0890-z Monoterpenes as inhibitors of digestive enzymes and counter-adaptations in a specialist avian herbivore [Elektronische Daten] [Kevin Kohl, Elizabeth Pitman, Brecken Robb, John Connelly, M. Dearing, Jennifer Forbey] Many plants produce plant secondary metabolites (PSM) that inhibit digestive enzymes of herbivores, thus limiting nutrient availability. In response, some specialist herbivores have evolved digestive enzymes that are resistant to inhibition. Monoterpenes, a class of PSMs, have not been investigated with respect to the interference of specific digestive enzymes, nor have such interactions been studied in avian herbivores. We investigated this interaction in the Greater Sage-Grouse (Phasianidae: Centrocercus urophasianus), which specializes on monoterpene-rich sagebrush species (Artemisia spp.). We first measured the monoterpene concentrations in gut contents of free-ranging sage-grouse. Next, we compared the ability of seven individual monoterpenes present in sagebrush to inhibit a protein-digesting enzyme, aminopeptidase-N. We also measured the inhibitory effects of PSM extracts from two sagebrush species. Inhibition of aminopeptidase-N in sage-grouse was compared to inhibition in chickens (Gallus gallus). We predicted that sage-grouse enzymes would retain higher activity when incubated with isolated monoterpenes or sagebrush extracts than chicken enzymes. We detected unchanged monoterpenes in the gut contents of free-ranging sage-grouse. We found that three isolated oxygenated monoterpenes (borneol, camphor, and 1,8-cineole) inhibited digestive enzymes of both bird species. Camphor and 1,8-cineole inhibited enzymes from chickens more than from sage-grouse. Extracts from both species of sagebrush had similar inhibition of chicken enzymes, but did not inhibit sage-grouse enzymes. These results suggest that specific monoterpenes may limit the protein digestibility of plant material by avian herbivores. Further, this work presents additional evidence that adaptations of digestive enzymes to plant defensive compounds may be a trait of specialist herbivores. Springer-Verlag Berlin Heidelberg, 2015 Aminopeptidase-N nationallicence Digestive enzymes nationallicence Greater sage-grouse nationallicence Monoterpenes nationallicence Sagebrush nationallicence Kohl Kevin Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut Pitman Elizabeth Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut Robb Brecken Department of Biological Sciences, Boise State University, 83725, Boise, ID, USA aut Connelly John Idaho Department of Fish and Game, 83221, Blackfoot, ID, USA aut Dearing M. Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut Forbey Jennifer Department of Biological Sciences, Boise State University, 83725, Boise, ID, USA aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 425-434 0174-1578 185:4<425 2015 185 360 https://doi.org/10.1007/s00360-015-0890-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0890-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kohl Kevin Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Pitman Elizabeth Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Robb Brecken Department of Biological Sciences, Boise State University, 83725, Boise, ID, USA aut NATIONALLICENCE 700 1- Connelly John Idaho Department of Fish and Game, 83221, Blackfoot, ID, USA aut NATIONALLICENCE 700 1- Dearing M. Department of Biology, University of Utah, 257 S. 1400 East, 84112, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Forbey Jennifer Department of Biological Sciences, Boise State University, 83725, Boise, ID, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 425-434 0174-1578 185:4<425 2015 185 360