Mechanisms of NB-LRR disease resistance protein function

Plants are fertile sources of nutrients for a variety of microbes. Many of these reduce plant fitness and productivity, and hence are pathogens. Plant pathogens devastate crops, particularly in developing areas where expensive (and often unsustainable) fungicides and pesticides are beyond the economic reach of most farmers. Yield losses due to plant disease are also 'water losses', since that resource is often invested before disease decimates a crop. Hence, successfully combating plant diseases through rational deployment of the plant immune system will contribute directly to human and environmental health, and save lots of fresh water. The plant immune system uses a family of proteins to recognize the proteins of invasive microbes. The key plant proteins are called 'disease resistance receptors' and have the acronym NLR, which reflects their particular set of protein domains. Recognition of pathogen molecules by NLRs results in a successful immune response that halts pathogen growth. Plant breeders have unknowingly manipulated NLRs for over 100 years, and all of our crop plants rely on their set of NLRs to protect them from microbial pathogens. However, because the generation times of microbes are very short, and crops by contrast very slow, microbes evolve faster and they can evade the slow work of plant breeders to anticipate how diseases will emerge. The investigators study the precise mechanisms by which NLR proteins are activated, and the consequences of that activation. Their work uses genomics, genetics, biochemistry and cell biology to understand how these important proteins work. Their research will lead to better tools with which to design more efficient plant immune receptors and responses to protect our food security. Similarly, animal NLR receptors respond to microbial signals in hosts as diverse as sea urchins and humans. Hence, the broadest impacts of the proposed research project will significantly inform translation to crop species and to human health.