Differential effects of condensed and hydrolyzable tannin on polyphenol oxidase activity of attine symbiotic fungus |
| |
Authors: | Colin Nichols-Orians |
| |
Affiliation: | (1) Present address: Department of Biology, Vassar College, 12601 Poughkeepsie, New York;(2) Department of Entomology, Pennsylvania State University, 16802 University Park, Pennsylvania |
| |
Abstract: | The leaf-cutting antAtta cephalotes is a generalist herbivore of the neotropics and collects leaf material to cultivate a fungus. It appears that this fungus, a Basidiomycete, is responsible for the ability of the ants to utilize most of the available woody plant species. Tannins and other phenolics are ubiquitous secondary chemicals in woody plants, and Basidiomycete fungi produce enzymes, such as polyphenol oxidase, that are capable of polymerizing and inactivating the phenolics. This study evaluates the effects of a condensed and a hydrolyzable tannin on the activity of polyphenoi oxidase and the growth of the fungus. I hypothesized that low concentrations of tannin would not inhibit polyphenol oxidase activity but high concentrations would inhibit the enzyme. Consequently, I predicted that only high concentrations of tannin would inhibit fungal growth. Laboratory assays with the fungus indicated that hydrolyzable tannin (tannic acid) and condensed tannin (quebracho tannin) differ in the mechanism of inhibition. Tannic acid does not inhibit polyphenol oxidase activity but does inhibit fungal growth. Quebracho tannin, however, inhibits both polyphenol oxidase activity and fungal growth. As predicted, both tannic acid and quebracho tannin primarily inhibit the fungus at high concentrations. |
| |
Keywords: | Atta cephalotes Hymenoptera Formicidae attine fungus fungal performance condensed tannin hydrolyzable tannin polyphenol oxidase |
本文献已被 SpringerLink 等数据库收录! |
|