Abstract 2350 Involvement of invertebrate defensins in plant-fungal interactions

Fungal pathogens utilize a variety of small, secreted proteins known as effectors to facilitate host infection. These effectors play a vital role in modulating plant immune responses and manipulating host physiology to aid in pathogenesis. The species complex Fusarium oxysporum contains many fungal pathogens that infect over 100 plant hosts, making them it an excellent model system to investigate the involvement of fungal effectors in plant-fungal interactions. We identified a conserved effector, invertebrate defensin (FoID), belonging to a family of antimicrobial peptides associated with innate immunity. This expression of this effector was highly upregulated during a F. oxysporum pathogen Fo5176 infecting the model plant Arabidopsis thaliana based on meta-transcriptomic data. Originally found in invertebrates, functional involvement of this effector in fungal-plant interaction remains unclear. In this presentation, we will present 1) phylogenetic analysis of defensins, including those from invertebrates, and the other defensin effectors within the F. oxysporum species complex, particularly those induced during F. oxysporum-plant interactions; 2) Sequence and structural analyses to identify highly conserved amino acid residues, such as cysteines, and structural conservations. 3) Heterologous expression using Nicotiana tabacum plants to detect the production and accumulation of reactive oxygen species (ROS) and other indicating signals to detect their involvement in plant-pathogen interaction. As an undergraduate research project, this research will increase our understanding of the invertebrate defensin effector and their potential involvement in plant-fungal interactions. Based upon work supported by the National Science Foundation under project number IOS-165241 and National Institute of Food and Agriculture, U.S. Department of Agriculture, the Center for Agriculture, Food and the Environment and the Biochemistry and Molecular department at University of Massachusetts Amherst, under project number MSA00496 and MAS00612.