Investigating Solanum tuberosum induced response to Bactericera cockerelli feeding and ‘Candidatus Liberibacter solanacearum’ infection

The potato/tomato psyllid, Bactericera cockerelli, is a national agricultural concern as it vectors the bacterium ‘Candidatus Liberibacter solanacearum’ (CLs) which infects solanaceous and causes Zebra Chip disease in potato, Solanum tuberosum. Zebra Chip is an emergent disease that continues to spread throughout the United States and the world. Today, it is responsible for million dollars losses. Zebra Chip disease has been spreading so quickly and efficiently that little is known about its epidemiology, and control depends solely on pesticide applications against its vector. The main objective of our research is to understand the interaction between plant, vector and/or pathogen. Here, we are interested in the following questions: 1) How does potato defend against psyllid and/or CLs? 2) Do vectors benefit from transmitting the pathogen? To answer these questions, induction of genes involved in plant defense was monitored in potato plants after a) feeding by 20 psyllid nymphs harboring CLs, b) feeding by 20 psyllid nymphs not harboring CLs and c) no psyllid nymph herbivory. Insects were allowed to feed on the plants for 3 days. One week and three weeks post-feeding, plant tissues were collected for RNA extraction, cDNA synthesis and gene expression test. Our results will help understanding Zebra Chip epidemiology, a stepping stone on the process of developing effective control strategies against the disease and its vector.