Gary Felton, Ph.D.

Current Graduate Students:

Wilma Aponte (Ph.D.)
Seung Ho Chung (Ph.D.)
Jinwon Kim (Ph.D.)
Helene Quaghebeur (Ph.D.)
Erica Shoemaker (M.S.)
Katherine Szulewski (M.S.)
Donglan Tian (Ph.D.)
Hao Zheng (Ph.D.)

Department Focus Areas:

Chemical ecology

Research:

Chemical ecology: Insect-plant interactions; physiological mode-of-action of plant natural products; oxidative stress and insect biology; nutritional physiology

Saliva collection from the spinneret of H. zea - Michelle Peiffer's Oscar-winning video on Caterpillar Saliva

Research Programs and Interests:

My research program uses molecular, proteomic and physiological approaches to investigate insect-plant interactions. My main interests are investigating the counter measures herbivores use in overcoming host plant defenses. Particular interest is on the role of herbivore salivary signals in suppressing the induced defenses of host plants.

The role of saliva of blood feeding arthropods in suppressing the defenses of their vertebrate hosts has been comparatively well studied; however, very little is known about how the saliva of herbivores may interfere with plant defensive responses. Our projects focus primarily on the saliva of caterpillars. Recent findings indicate that saliva is enriched with an array of molecules that function in defense against microbial infection, digestion of plant tissues, and in suppressing induced defenses of plants. We employ a variety of surgical and genetic approaches (e.g., RNA interference) to examine function(s) of saliva.

Relevant Publications:

Johnson, K. S. and Felton, G. W. 2001. Plant phenolics as dietary antioxidants for insects: a test with genetically modified tobacco. J. Chem.Ecol. 27: 2579-2597.

Johnson, K. S. and Felton, G. W. 2001. Plant phenolics as dietary antioxidants for insects: a test with genetically modified tobacco. J. Chem.Ecol. 27: 2579-2597.

Musser, R. A., Hum-Musser, S., Eichenseer, H., Peiffer, M., Ervin, G., Murphy, B. and Felton, G. W. 2002. Caterpillar saliva beats plant defences: a new weapon emerges in the evolutionary arms race between plants and herbivores. Nature 416:599-600.

Karban, R., Maron, J., Felton, G.W., Ervin, G. and Eichenseer, H. 2003. Herbivore damage to sagebrush induces wild tobacco: evidence for eavesdropping between plants. Oikos 100: 325-333.

Musser, R.O., Farmer, E., Peiffer, M, and Felton G. W. 2003. Ablation of caterpillar labial salivary glands: technique for the determining the role of saliva in insect-plant interactions. Journal of Chemical Ecology (in press)

Ali, M. I., J. L. Bi, S. Y. Young, and G. W. Felton. 1999. Do foliar phenolics provide protection to Heliothis virescens from a baculovirus? J Chem Ecol 25: 2193-2204.

Eichenseer, H., M. C. Mathews, J. L. Bi, J. B. Murphy, and G. W. Felton. 1999. Salivary glucose oxidase: multifunctional roles for Helicoverpa zea? Arch Insect Biochem Physiol 42: 99-109.

Felton, G. W., K. L. Korth, J. L. Bi, S. V. Wesley, D. V. Huhman, M. C. Mathews, J. B. Murphy, C. Lamb, and R. A. Dixon. 1999. Inverse relationship between systemic resistance of plants to microorganisms and to insect herbivory. Current Biology 9: 317-320.

Felton, G. W., and K. L. Korth. 2000. Trade-offs between pathogen and herbivore resistance. Current Opinion in Plant Biology 3: 309-314.

Johnson, K. S., and G. W. Felton. 2001. Plant phenolics as dietary antioxidants for herbivorous insects: A test with genetically modified tobacco. J Chem Ecol 27: 2579-2597.
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Ali, I. M., S. Y. Young, G. W. Felton, and R. W. McNew. 2002. Influence of the host plant on occluded virus production and lethal infectivity of a baculovirus. J Invertebr Pathol 81: 158-65.

Musser, R. O., S. M. Hum-Musser, H. Eichenseer, M. Peiffer, G. Ervin, J. B. Murphy, and G. W. Felton. 2002. Herbivory: caterpillar saliva beats plant defences. Nature 416: 599-600.

Karban, R., J. Maron, G. W. Felton, G. Ervin, and H. Eichenseer. 2003. Herbivore damage to sagebrush induces resistance in wild tobacco: evidence for eavesdropping between plants. Oikos 100: 325-332.

Liu, F., L. Cui, D. Cox-Foster, and G. W. Felton. 2004. Characterization of a salivary lysozyme in larval Helicoverpa zea. J Chem Ecol 30: 2439-57

Boughton, A. J., K. Hoover, and G. W. Felton. 2005. Methyl jasmonate application induces increased densities of glandular trichomes on tomato, Lycopersicon esculentum. J Chem Ecol: -46--46.

Felton, G. W. 2005. Indigestion is a plant's best defense. Proc Natl Acad Sci 102: 18771-18772.

Musser, R. O., D. F. Cipollini, S. M. Hum-Musser, S. A. Williams, J. K. Brown, and G. W. Felton. 2005a. Evidence that the caterpillar salivary enzyme glucose oxidase provides herbivore offense in solanaceous plants. Arch Insect Biochem Physiol 58: 128-37.

Musser, R. O., H. S. Kwon, S. A. Williams, C. J. White, M. A. Romano, S. M. Holt, S. Bradbury, J. K. Brown, and G. W. Felton. 2005b. Evidence that caterpillar labial saliva suppresses infectivity of potential bacterial pathogens. Arch Insect Biochem Physiol 58: 138-144.

Peiffer, M., and G. W. Felton. 2005. The host plant as a factor in the synthesis and secretion of salivary glucose oxidase in larval Helicoverpa zea. Arch Insect Biochem Physiol 58: 106-13.

Bede, J.C., Musser, R.O., Felton, G.W. and K.L. Korth. 2006. Caterpillar herbivory and salivary enzymes decrease transcript levels of Medicago truncatula genes encoding early enzymes in terpenoid biosynthesis. Plant Mol. Biol. (in press).