MOLECULAR BASIS OF MICROBIOME-MEDIATED DEFENSE AGAINST APHID HERBIVORY IN TOMATO

Damage caused by pest insects represents a major threat to global food security. Natural hostplant resistance is one of the most effective and sustainable ways to combat insects, but theevolution of increasingly virulent pests capable of overcoming plant defenses continues tothreaten the durability of existing sources of resistance. Plant-associated microbes essential tooverall health and protection from pests and pathogens have become a target for developingnovel biologically-based pest control tactics, but single microbe inoculants often fail to conferprotection in field settings. Plant-host genetics may play a role in modulating interactions withthe microbiome under stressful conditions, but the role of plant genetic variation in microbiomeinteractions is poorly understood. The tomato-Green Peach Aphid (GPA) interaction provides anideal model system as natural variation in both root microbial communities and aphid resistancehave been found. This study aims to characterize the molecular basis of microbiome-mediatedtomato genetic resistance to GPA herbivory through the following research objectives:1. To assess the contribution of the soil microbiome to general and genotype-specific GreenPeach aphid resistance in two tomato lines.2. To characterize the role of microbial community structure in mediating general andgenotype-specific plant defense responses to Green Peach aphids.The long-term goal of this project is to develop novel approaches to reducing pestdamage through identifying genetic loci and underlying mechanisms for pest-protectivemicrobiome-plant associations. The completion of these aims, together with focused training inprofessional skills, will prepare me to meet my career goal of being an independently fundedresearcher in the agricultural sciences.