My group is addressing fundamental questions in evolutionary biology, using both genome- and phenotype-first approaches. A few years ago, we discovered that Arabidopsis thaliana is a great model for the study of hybrid necrosis. This widespread syndrome of hybrid failure in plants is caused by plant paranoia – regardless of the presence of enemies, plants “think” they are being attacked by pathogens. Over the past decade, we have studied in detail the underlying genetics, finding that often one or two loci encoding NLR immune receptors are causal. NLRs make up the most variable gene family in plants, and it is not surprising that they are often involved in genome-genome conflicts. Hybrid necrosis results when NLR genes meet that have not been co-adapted. Our goal for the next decade is to understand the genomic and geographic patterns for immune system diversity. In 2018, we initiated a project, Pathodopsis, in which we aim to describe genetic diversity in the host A. thaliana and two of its important pathogens, the generalist Pseudomonas sp. and the specialist Hyaloperonospora arabidopsidis. The long-term vision is to produce maps of resistance alleles in the host, and of effector alleles in the pathogens, in order to learn when the pathogens win in a wild plant pathosystem – and when the hosts prevail. Additional information about our work can be found on our websites, http://weigelworld.org and http://pathodopsis.org.

Learning Objectives:

1. Understand drivers of plant immune receptor diversity

2. Understand limits of plant immune receptor diversity