CURRICULUM VITAE ⸺ Daniel J. Ballhorn

Education

Ph.D.; 2006 (summa cum laude); Applied Botany - Terrestrial Ecology; University of Hamburg, Germany.

Diploma (equivalent to M.S.; with distinction); 2002; Applied Botany - Plant Ecology; University of Hamburg, Germany.

Pre-Diploma (equivalent to B.A.); 1999; Biology; University of Hamburg, Germany.

Academic & Administrative Appointments

Chair, Department of Biology, Portland State University, College of Liberal Arts & Sciences; Department of Biology, OR, USA. 09/2020 – 08/2023.

Assistant Chair, Department of Biology, Portland State University, 08/2019 – 09/2020.

Full Professor, Department of Biology, Portland State University, 06/2018 – present (Early Promotion).

CLEE Faculty (Excellence Center, Center for Life in Extreme Environments), Department of Biology, 08/2018 – present.

Associate Professor, Department of Biology, 02/2016 – 05/2018 (Early Promotion and Tenure).

Assistant Professor, Department of Biology, OR, USA. 10/2011 – 05/2016.

Research Associate, Field Museum of Natural History, Chicago, IL, USA. 07/2010 – present.

Postdoctoral fellow, University of Minnesota, Department of Plant Biology, MN, USA. 12/2009 – 09/2011.

Co-Chair of the Botany Department of the University of Duisburg-Essen, Germany. 08/2007 – 10/2009.

Postdoctoral fellow, University of Duisburg-Essen, Germany; General Botany – Plant Ecology. 07/2006 – 07/2007.

Research Associate, University of Duisburg-Essen, Germany; General Botany – Plant Ecology. 04/2005 – 07/2006.

Research Associate, University of Hamburg, Germany; EU project ECOMAN (Decision Support System for Sustainable Ecosystem Management in Atlantic Rainforest Rural Areas; INCO2 project contract ICA4-CT-2001) and BMBF project SHIFT (Studies on Human Impact on Forest and Floodplains in the Tropics; No.:0339991). 07/2002 – 01/2005.

Dissertation

Cyanogenesis of lima bean (Phaseolus lunatus L.) — functional and quantitative analysis of its efficiency in herbivore-plant interactions, 2006, Advisors: Profs. Dr. Lieberei & Jӧrg Ganzhorn.

Refereed Publications or Other Creative Achievements (selected)

Book Chapters

Schädler M. & Ballhorn D.J. Beneficial soil microbiota as mediators of the plant defensive phenotype and aboveground plant-herbivore interactions. Progress in Botany, 2017, 78: 305–344.

Ballhorn D.J. Nuts and seeds in health and disease prevention. Book chapter: Cyanogenic glycosides in nuts and seeds. V.R. Preedy, R.R. Watson & V. Patel (eds.), Academic Press, Elsevier Science and Technology, MO, USA, 2017 pp.129-136.

Peer-Reviewed Publications (selected)

Nettle J., Ballhorn D.J., Kautz S. Phenotypic Plasticity of Quercus garryana seedlings in response to climate treatments. Northwest Science (under review).

Dove R., Wolfe E.R., Stewart N.U., Coleman A., Chavez S.H., Ballhorn D.J. Root nodules of red alder (Alnus rubra) and Sitka alder (Alnus viridis ssp. sinuata) are inhabited by taxonomically diverse cultivable microbial endophytes. MicrobiologyOpen (accepted for publication, + Cover).

Bustos-Segura C., Godschalx A.L., Malacari L., Deiss F., Rasmann S, Ballhorn D.J., Benrey B. Rhizobia-legume symbiosis mediates direct and indirect interactions between plants, herbivores and their parasitoids. Heliyon, 2023, 10(6).

Godschalx A.L., Diethelm A.C., Kautz S., Ballhorn D.J. Nitrogen-fixing rhizobia affect multitrophic interactions in the field, J Insect Behav, 2023, 36:168–179.

Younginger B.S., Stewart N.U., Balkan M.A., Ballhorn D.J. Stable coexistence or competitive exclusion? Fern endophytes demonstrate rapid turnover favoring a dominant fungus. Mol Ecol, 2022, 00:1-14.

Wolfe E.R., Singleton S., Stewart N.U., Balkan M.A., Ballhorn D.J. Frankia diversity in sympatrically occurring red alder (Alnus rubra) and Sitka alder (Alnus viridis) trees in an early successional environment. Trees, 2022, 36(5):1665-1675.

Wolfe E.R., Dove R., Webster C., Ballhorn D.J. Culturable fungal endophyte communities of primary successional plants on Mount St. Helens, WA, USA. BMC Ecology and Evolution. 2022, 22(1) Article Number 18.

Van Court R.C., Wiseman M.S., Meyer K.W., Ballhorn D.J., Amses K.R., Slot J.C., Dentinger B.T.M., Garibay-Orijel R., Uehling J.K. Diversity, biology, and history of psilocybin-containing fungi: Suggestions for research and technological development. Fungal Biology, 2022, 126(4):308-319.

Dove R., Wolfe E.R., Stewart N.U., Ballhorn D.J. Ecoregion—rather than sympatric legumes—influences symbiotic Bradyrhizobium associations in invasive Scotch broom (Cytisus scoparius) in the Pacific Northwest. Northwest Science, 2020, 94(2):142-159.

Wolfe E.R., Ballhorn D.J. Do foliar endophytes matter in litter decomposition? Microorganisms, 2020, 8:446-458.

Balkan M.A., Stewart N.U., Kauffman E.S., Ballhorn D.J. Genotypic diversity and host-specificity of Frankia bacteria associated with sympatric populations of Alnus rubra and Alnus rhombifolia in Oregon. Northwest Science, 2020, 93:244-252.

Vadassery J., Ballhorn D.J.,  Fleming S.R, Mazars C., Pandey S.P., Schmidt A., Schuman, M.C.,  Yeh K.W., Yilamujiang A., Mithöfer A. Neomycin: An effective inhibitor of jasmonate-induced reactions in plants. J Plant Growth Reg, 2019, 38:713-722.

Ballhorn D.J., Wolfe E.R., Tyler J., Ronan W., Sands-Gouner S., Shaw C., Balkan M.A. & Kautz S. (2018) Quantitative effects of soil salinity on the symbiosis of wild lima bean (Phaseolus lunatus L.) and Bradyrhizobium in Costa Rica. J Appl Bot Food Qual, 2018, 91:304-309.

Wolfe E.R., Kautz S., Singleton S.L., Ballhorn D.J. Differences in foliar endophyte communities of red alder (Alnus rubra) exposed to varying air pollutant levels. Botany, 2018, 96:825-835.

Godschalx A.L., Tran V. & Ballhorn D.J. Host plant cyanotype determines degree of rhizobial symbiosis. Ecosphere, 2017, 8: e01929.

Eppley T.M., Tan C., Arrigo-Nelson S., Donati G., Ballhorn D.J., Ganzhorn J.U. High energy or  protein concentrations in food as possible offsets for cyanide consumption by specialized bamboo lemurs in Madagascar. Int J of Primatol, 2017, 38:881-899.

Younginger B.S., Ballhorn D.J. Fungal endophyte communities in the temperate fern, Polystichum munitum, show early colonization and extensive temporal turnover. Am J Bot, 2017, 104 (8), 1188-1194.

Ballhorn D.J., Elias J.D., Balkan M.A., Fordyce R.F., Kennedy P.G. Colonization by nitrogen-fixing Frankia bacteria causes short-term increases in herbivore susceptibility in red alder (Alnus rubra) seedlings. Oecologia, 2017, 184:497-506.

Kautz S., Williams T., Ballhorn D.J. Ecological importance of cyanogenesis and extrafloral nectar in invasive English laurel, Prunus laurocerasus. Northwest Science, 2017, 9:214-221.

Younginger B.S., Sirová D, Cruzan, M. B., Ballhorn D.J. Plant size as an indicator of fitness; a look across the lineages. Appl Plant Sci, 2017, 5(2).

Ballhorn D.J., Rakotoarivelo F.P., Kautz S. Coevolution of cyanogenic bamboos and bamboo lemurs on Madagascar. PLoS ONE, 2016, 11: e0158935.

Ballhorn D.J., Schädler M., Elias J.D., Millar J.A., Kautz S. Friend or foe - light availability determines the relationship between mycorrhizal fungi, rhizobia and lima bean (Phaseolus lunatus L.). PloS ONE, 2016, 11(5): e0154116.

Ballhorn D.J., Kautz S., Laumann J.M.. Herbivore damage induces a transgenerational increase of cyanogenesis in wild lima bean (Phaseolus lunatus). Chemoecology, 2016, 26:1-5.

Godschalx A.L., Stady L., Watzig B., Ballhorn D.J. Is protection against florivory consistent with the optimal defense hypothesis? BMC Plant Biol, 2016,16:32.

Godschalx A.L., Schädler M., Trisel J.A., Balkan M.A., Ballhorn D.J. Ants are less attracted to the extrafloral nectar of plants with symbiotic, nitrogen-fixing rhizobia. Ecology, 2015, 96:348-354.

Blue E., Kay J., Younginger B.S., Ballhorn D.J. Differential effects of type and quantity of leaf damage on growth, reproduction and defense of lima bean (Phaseolus lunatus L.). Plant Biol, 2015, 17:712-719.

Kautz S., Trisel J.A., Ballhorn D.J.  Jasmonic acid enhances plant cyanogenesis and resistance to herbivory in lima bean. J Chem Ecol, 2014, 40:1186-1196.

Ballhorn D.J., Younginger B., Kautz S. Aboveground pathogens inhibit belowground rhizobia and mycorrhizal fungi in Phaseolus vulgaris. BMC Plant Biol, 2014, 14:321.

Ballhorn D.J., Godschalx A.L., Smart S.M., Kautz S., Schädler M. Chemical defense lowers plant competitiveness. Oecologia, 2014, 176:811-824.

Ballhorn D.J., Elias J.D. Salinity-mediated cyanogenesis in white clover (Trifolium repens L.) affects trophic interactions. Ann Bot, 2014, 114:357-366.

Ballhorn D.J., Kay J. & Kautz S. Quantitative effects of leaf area removal on indirect defense of lima bean (Phaseolus lunatus) in nature. J Chem Ecol, 2014, 40:294-296.

Millar J.A. & Ballhorn D.J. Effect of mycorrhizal colonization and light limitation on growth and reproduction of lima bean (Phaseolus lunatus L.). J Appl Bot Food Qual, 2013, 86:172-179.

De Roissart A., de la Peña E., Van Oyen L., Van Leeuwen T., Ballhorn D.J. & Bonte D. The presence of root-feeding nematodes - not AMF - affects an herbivore dispersal strategy. Acta Oecol, 2013, 52:38-44.

Ballhorn D.J. & Kautz S. How useful are olfactometer experiments in chemical ecology research? Comm & Int Biol, 2013, 6:e24787.

Ballhorn D.J., Godschalx A.L. & Kautz S. Co-variation of chemical and mechanical defenses in lima bean (Phaseolus lunatus L.). J Chem Ecol, 2013, 39:413-417.

Ballhorn D.J., Kautz S. & Heil M. Distance and sex determine host plant choice by herbivorous beetles. PLoS ONE, 2013, 8(2):e55602.

Ballhorn D.J., Kautz S. & Schädler M. Induced plant defense via volatile production is dependent on rhizobial symbiosis. Oecologia, 2013, 172:833-846.

Wybouw N.R., Balabanidou V., Ballhorn D.J., Dermauw W., Grbić M., Vontas J. & Van Leeuwen T. A horizontally transferred cyanase gene in the spider mite Tetranychus urticae is involved in cyanate metabolism and is differentially expressed upon host plant change. Insect Biochem Mol Biol, 2012, 42:881-889.

Kautz S., Ballhorn D.J., Kroiss J., Pauls S.U., Moreau C.S., Eilmus S., Strohm E. & Heil M. Host plant use by competing acacia-ants: mutualists monopolize while parasites share hosts. PLoS ONE, 2012, 7(5):e37691.

Ballhorn D.J., Reisdorff C. & Pfanz H. Quantitative effects of enhanced CO2 on jasmonic acid induced plant volatiles of lima bean (Phaseolus lunatus L.). J Appl Bot Food Qual, 2011, 84:65-71.

Ballhorn D.J. Constraints of simultaneous resistance to a fungal pathogen and an insect herbivore in lima bean (Phaseolus lunatus L.). J Chem Ecol, 2011, 37:141-144.

Thamer S., Schädler M., Bonte D. & Ballhorn D.J. Dual benefit from a belowground symbiosis: nitrogen fixing rhizobia promote growth and defense against a specialist herbivore in a cyanogenic plant. Plant & Soil, 2011, 341:209-219.

Ballhorn D.J., Kautz S., Jensen M., Schmitt I., Heil M. & Hegeman A.D. Genetic and environmental effects on plant defences against herbivores. J Ecol, 2011, 99:313-326.

Ballhorn D.J., Schmitt I., Fankhauser J.D., Katagiri F. & Pfanz H. CO2 mediated changes of plant traits and their effects on herbivores are determined by leaf age. Ecol Entomol, 2010, 36:1-13.

Bonte D., de Roissart A., Vandegehuchte M., Ballhorn D.J. & de la Peña E. Local adaptation of aboveground herbivores towards plant phenotypes induced by biotic belowground agents. PLoS ONE, 2010, e11174.

Ballhorn D.J., Kautz S. & Lieberei R. Comparing responses of generalist and specialist herbivores to various cyanogenic plant features. Entomol Exp Appl, 2010, 134:245-259.

Ballhorn D.J., Pietrowski A. & Lieberei R. Direct trade-off between cyanogenesis and resistance to a fungal pathogen in lima bean (Phaseolus lunatus L.). J Ecol, 2010, 98:226-236 (+ Cover).

Kautz S., Pauls S.U., Ballhorn D.J., Lumbsch H.T., Heil M. Polygynous supercolonies of the acacia-ant Pseudomyrmex peperi, an inferior colony founder. Mol Ecol, 2009, 18:5180-5194.

Yi H.S., Heil M., Adame-Alvarez, R.M., Ballhorn D.J. & Ryu C.M. Airborne induction and priming of plant defenses against a bacterial pathogen. Plant Physiol, 2009, 151:2152-2161.

Ballhorn D.J., Kautz S., Heil M. & Hegeman A.D. Analyzing plant defenses in nature. PS & B, 2009, 4:743-745.

Ballhorn D.J., Kautz S., Heil M. & Hegeman A.D. Cyanogenesis of wild lima bean (Phaseolus lunatus L.) is an efficient and direct defense in nature. PLoS ONE, 2009, e5450.

Ballhorn D.J., Kautz S. & Rakotoarivelo F.P. Quantitative variability of cyanogenesis in Cathariostachys madagascariensis ― the main food plant of bamboo lemurs in southeastern Madagascar. Am J Primatol, 2009, 71:305-315.

Kautz S., Schmid V.S., Trindl A., Heinze J., Ballhorn D.J. & Heil M. Isolation and characterization of microsatellite loci in the plant-ant Pseudomyrmex ferrugineus (Formicidae: Pseudomyrmecinae) and cross-testing for two congeneric species. Mol Ecol Res, 2009, 9:1016-1019.

Ale-Agha N., Jensen M., Brassmann M., Kautz S., Eilmus S. & Ballhorn D.J. Rare or remarkable microfungi from Oaxaca (South Mexico) Part II. Comm Agr Appl Biol Sci, 2008, 73:147-155.

Ballhorn D.J., Schiwy S., Jensen M. & Heil M. Quantitative variability of direct chemical defense in primary and secondary leaves of lima bean (Phaseolus lunatus) and consequences for a natural herbivore. J Chem Ecol, 2008, 34:1298-1301.

Ballhorn D.J., Kautz S., Lion U. & Heil M. Qualitative variability of lima bean’s VOC bouquets and its consequences on plant-plant communication. PS & B, 2008, 3:1005-1007.

Ballhorn D.J., Kautz S., Lion U. & Heil M. Trade-offs between direct and indirect defences of lima bean (Phaseolus lunatus). J Ecol, 2008, 96:971-980 (+ Cover).

Ballhorn D.J., Pietrowski A., Heil M. & Lieberei R. Quantitative effects of cyanogenesis on an adapted herbivore. J Chem Ecol, 2007, 33:2195-2208.

Ballhorn D.J. & Lieberei R. Oviposition choice of Mexican bean beetle Epilachna varivestis depends on host plant cyanogenic capacity. J Chem Ecol, 2006, 32:1861-1865. (Most downloaded paper).

Ballhorn D.J., Heil M. & Lieberei R. Phenotypic plasticity of cyanogenesis in lima bean Phaseolus lunatus — Activity and activation of β-glucosidase. J Chem Ecol, 2006, 32:261-275.

Ballhorn D.J., Lieberei R. & Ganzhorn J.U. Plant cyanogenesis of Phaseolus lunatus and its relevance for herbivore-plant interaction: The importance of quantitative data. J Chem Eco, 2005, 31:1445-1473.

Non-Refereed Publications or Other Creative Achievements

Millar J.A. & Ballhorn D.J. Effects of light limitation on plant-rhizobia and plant-mycorrhiza interactions. Anthós, 2012, 4(2).

van Strien D.W. (edited by Ballhorn D.J.) Limaboon maakt nakomelingen weerbaar (in Dutch). Bionieuws, 2015. 25:8. p.4.

Teaching at Portland State University

Plant Anatomy BI-434/534. Winter 2024

Chem-Bio CURE (BI448). Fall 2018 - 2024

Introduction to Plant Biology (BI330). Fall 2012-2024

Chemical Plant Biology (BI438/538). Fall 2013 - 2015.

Principles of Biology BI-212/BI-215. Winter 2012-2020.

Chemical Ecology BI407/BI507. Fall 2012.