Associations between Wolbachia, maize and Diabrotica virgifera virgifera

Increasing demand for ethanol is motivating growers to increase maize production reducing production of other crops. WCR is the most significant and widespread pest to maize in North America and is becoming so in parts of Europe. It has surmounted chemical and cultural control strategies. Currently, selection for native resistance to WCR is driven by phenotypic expression. The goal of this study was to identify maize genes unique to WCR feeding with the hope of locating genes specific for insect defense. A maize microarray experiment was performed to identify WCR-responsive genes and mutants of candidate genes were assayed to confirm their involvement in WCR feeding response. Surprisingly the number of commonly employed insect defense genes which were differentially expressed was low. Interestingly, genes involved in bacterial defense, chromatin remodeling, and gene silencing were among those identified as WCR-specific. Nine genes currently not associated with insect defense in plants were differentially expressed in response to WCR feeding. The results suggest a bacterium capable of altering gene expression may contribute to the WCR feeding-specific changes in maize seminal root gene expression.