Our central efforts in the area of natural variation revolve around fitness tradeoffs in immunity. Several years ago, we introduced Arabidopsis thaliana as a model for hybrid necrosis, a syndrome that is characterized by activation of the immune system due to inappropriate self-recognition in the progeny of crosses among natural accessions. From a systematic analysis of thousands of crosses, we have identified dozens of hybrid necrosis cases. A main insight from cloning the causal genes for many of these has been that many loci encode highly polymorphic NLR immune receptor genes (which include the major disease resistance or R genes in plants). Our working hypothesis is that the obvious cases that we have investigated so far are only the tip of the incompatibility iceberg, and that more subtle interactions among components of the immune system have a major impact on fitness of plants in the absence of pathogens. To test this hypothesis, we are both extending our genetic analyses and we are systematically reconstructing the full NLR complement of accessions.
Of continued interest is also the ACD6 locus for which we have identified hybrid necrosis variants that both compromise growth and activate the immune system on their own. We are studying natural modifiers to decipher the molecular pathways underlying this growth-immunity tradeoff in different accessions.
Cooperation and Conflict in the Plant Immune System, and
PLoS Pathog (2016), 12(3) e1005452.
Activation of the Arabidopsis thaliana immune system by combinations of common ACD6 alleles, , , , , , and
PLoS Genet (2014), 10(7) e1004459.
Different mechanisms for Arabidopsis thaliana hybrid necrosis cases inferred from temperature responses, , , , and
Plant Biol (Stuttg) (2014), 16(6) 1033-41.
Species-wide Genetic Incompatibility Analysis Identifies Immune Genes as Hot Spots of Deleterious Epistasis, , , , , , , , , , , , , , and
Cell (2014), 159(6) 1341-51.
On epigenetics and epistasis: hybrids and their non-additive interactionsand
EMBO J (2012), 31(2) 249-50.
Complex evolutionary events at a tandem cluster of Arabidopsis thaliana genes resulting in a single-locus genetic incompatibility, and
PLoS Genet (2011), 7(7) e1002164.
Local-scale patterns of genetic variability, outcrossing, and spatial structure in natural stands of Arabidopsis thaliana, , , , , , and
PLoS Genet (2010), 6(3) e1000890.
Natural allelic variation underlying a major fitness trade-off in Arabidopsis thaliana, , , , , , , , , , , , , , , , , and
Nature (2010), 465(7298) 632-6.
Autoimmune response as a mechanism for a Dobzhansky-Muller-type incompatibility syndrome in plants, , , , , and
PLoS Biol (2007), 5(9) e236.
Hybrid necrosis: autoimmunity as a potential gene-flow barrier in plant speciesand
Nat Rev Genet (2007), 8(5) 382-93.