Seminars with Daniel Ballhorn and Peter Solomon

Effects of Microbial Plant Symbionts on Insect Herbivores
by
Daniel J. Ballhorn, Ph.D.
Assistant Professor
Department of Biology
Portland State University

In natural and agricultural ecosystem plants frequently have to face attack by multiple herbivores and pathogens. While many plant defenses against both types of antagonists are well studied, the functional interplay of simultaneously expresses defense traits is much less understood. Furthermore, little information exist on how mutualistic microbial plant symbionts shape the defensive phenotype of their host plants. In my lab we use multitrophic systems to disentangle the functional interactions between plants and plant-associated organisms. 

Understanding the role of necrotrophic fungal effectors during disease on wheat
by
Peter Solomon
Associate Professor
Plant Sciences Division
Research School of Biology
The Australian National University

Until recently, we considered that necrotrophic fungal pathogens were simplistic and relied upon a battery of degradative enzymes to lyse cells and cause disease. However, it has now been demonstrated that some of these pathogens secrete effector proteins that interact specifically with dominant susceptibility loci in the host to facilitate disease. For the wheat pathogen Stagonospora nodorum, we have identified three secreted effector proteins which are required for disease. In this talk, I will discuss the role these proteins play in disease in terms of triggering plant cell death, as well as other possible roles. I will also touch briefly upon plant and fungal secondary metabolism projects that are ongoing in my laboratory