Plants face an onslaught of potential invaders. In order to mount successful defenses, plants specifically recognize the threat (microbe vs. herbivore) and mount the proper defense. As effective counterploys, herbivores may detoxify the chemical defenses of plants or even avoid these plants. The central hypothesis is that as a counterploy, some herbivores present themselves in "disguise" and thus avoid detection by plants. The investigators will study herbivores that exploit their gut bacteria by releasing them in their oral secretions on plants, and thus be "mistakenly" recognized as microbes. Consequently, plants turn on the incorrect defenses that are largely ineffective against these intruders. The hypothesis will be tested using biochemical and molecular approaches to identify specific oral bacteria responsible for suppressing plant defenses. The experimental system will include leaf-feeding beetles and caterpillars and several crop species (corn, soybeans, tomato) and wild plant species (wild Solanum, poplar, and Arabidopsis). The bacterial community of the oral secretions of the herbivores will be altered by dietary antibiotics and then tested for activity in suppressing plant defenses. Specific bacteria responsible for suppression will be identified and fully characterized at the molecular level. Thus the research work is transformative in expanding the understanding of how herbivores exploit their host plants.
Because the study system involves key agricultural crops/pests, the knowledge gained from these studies may have far-reaching impact on informing sustainable pest management. The role of the gut microflora of pest insects has largely been ignored, but could offer new targets that for pest management. The PIs will incorporate this research in an undergraduate course and interactive educational modules will be presented at various outreach opportunities for K-12 students. The investigators will also build upon previous outreach/educational programs to underserved audiences including children with Autism Spectrum Disorder and African-Americans.
