COS 46-2
Deciphering the language of plant communication: Volatile chemotypes of sagebrush

Tuesday, August 12, 2014: 1:50 PM
Golden State, Hyatt Regency Hotel
Rick Karban, Entomology, University of California at Davis, Davis, CA
William C. Wetzel, Center for Population Biology, University of California, Davis, Davis, CA
Kaori Shiojiri, Kyoto University, Kyoto, Japan
Satomi Ishizaki, Niigata University, Niigata, Japan
Santiago Ramirez, Department of Evolution and Ecology, University of California, Davis, CA
James Blande, University of Eastern Finland
Background/Question/Methods

Volatile communication between sagebrush individuals has previously been found to reduce herbivory and to be more effective between individuals that were genetically identical or related compared to strangers. The chemical nature of the cues remains unknown for any system. To identify potential cues, we collected headspace volatiles from sagebrush plants in the field and analyzed these using GC-MS. We also compared the effectiveness of volatile communication between experimentally clipped plants and neighbors of the same or a different chemotype.

Results/Conclusions

Volatile profiles were highly variable but most individuals could be characterized as belonging to one of two chemotypes, dominated by either thujone or camphor. Analyses of parents and offspring revealed that chemotypes were highly heritable (broad sense heritability = 0.98). The ecological significance of the chemotypes is not well understood although we found that individuals of the same chemotype communicated more effectively and experienced approximately 20% less herbivory than individuals of differing chemotypes.  Plants may use chemotypes as a first step to distinguish kin from strangers in order to favor communication between kin.