EAGER: The Mechanism of Induction of Plant Galls

San Francisco State University, San Francisco CA

Investigators

Abstract

This EAGER proposal will test the hypothesis that insects and other taxa that induce plant galls have acquired the necessary biosynthetic pathways from bacteria via symbiotic associations with bacteria or by horizontal gene transfer. If supported, this hypothesis would provide a comprehensive explanation for a very widespread evolutionary phenomenon, which is the origin of plant galls. Genomic DNA of a limited number of gall formers will be searched for evidence of transfer of bacterial genes. Molecular tools will then be used to demonstrate the presence of genes in gut versus non-gut tissues. This simple analysis should resolve whether the important gene sequences appear to be host- or bacterially-derived. The broader impacts of this EAGER are potentially very significant. Results could lay the foundation for methods to control insect, nematode, and protistan gall formers that cause extensive loss to agriculture and forestry. If these gall formers have acquired the ability to form galls from bacteria, then new approaches to control gall formation can be developed. The study also will provide a new, more parsimonious explanation for a very widespread ecological phenomenon.