Paper presented at the 51st Annual Meeting of the Entomological Society of America, October 2003. Symposium entitled Insect Saliva: An Integrative Approach.
Evidence that the caterpillar salivary enzyme glucose oxidase provides herbivore offense in solanaceous plants †
Article first published online: 19 JAN 2005
Copyright © 2005 Wiley-Liss, Inc.
Archives of Insect Biochemistry and Physiology
Special Issue: Insect Saliva: An Integrative Approach
Volume 58, Issue 2, pages 128–137, February 2005
How to Cite
Musser, R. O., Cipollini, D. F., Hum-Musser, S. M., Williams, S. A., Brown, J. K. and Felton, G. W. (2005), Evidence that the caterpillar salivary enzyme glucose oxidase provides herbivore offense in solanaceous plants . Arch. Insect Biochem. Physiol., 58: 128–137. doi: 10.1002/arch.20039
- Issue published online: 19 JAN 2005
- Article first published online: 19 JAN 2005
- Illinois Department of Agriculture
- University Research Council, Western Illinois University
- Center for Insect Science, University of Arizona
- Helicoverpa zea;
- reactive oxygen species;
- induced resistance;
- hydrogen peroxide;
- oxidative burst;
- systemic acquired resistance;
- glucose oxidase;
The insect salivary enzyme glucose oxidase (GOX) can inhibit wound-inducible nicotine production in tobacco, Nicotiana tabacum. We examined whether salivary gland extracts of Helicoverpa zea lacking active GOX could still suppress nicotine in tobacco, Nicotiana tabacum, and whether GOX could suppress wound-inducible defenses of another Solanaceous plant, tomato Lycopersicon esculentum. Tobacco leaves were wounded with a cork borer and treated with water, salivary gland extracts with active GOX (SxG), or salivary gland extracts with inactive GOX (SxI). After three days, leaves treated with SxG had significantly less nicotine than all other wounded treatments. Neonates that fed on the terminal leaves of tobacco plants treated with SxG had significantly higher survival than neonates that fed on leaves treated with either SxI or water. This evidence supports the assertion that GOX is the salivary factor responsible for the suppression of tobacco plant nicotine production by H. zea saliva. Results for the NahG tobacco plants, which lack salicylic acid (SA) due to a transgene for bacterial SA hydroxylase, indicate that suppression of nicotine by GOX does not require SA. However, tobacco leaves that were wounded and treated with SxG had significantly higher levels of the SA-mediated PR-1a protein than leaves treated with SxI or water. Leaves of tomato plants wounded with scissors and then treated with SxG had trypsin inhibitor levels that were moderately lower than plants wounded and treated with purified GOX, water, or SxI. However, all the wounded tomato leaves irrespective of treatment resulted in lower caterpillar growth rates than the non-wounded tomato leaves. Glucose oxidase is the first insect salivary enzyme shown to suppress wound-inducible herbivore defenses of plants. Arch. Insect Biochem. Physiol. 58:128–137, 2005. © 2005 Wiley-Liss, Inc.