Discovery of functional NLRs using expression level, high-throughput transformation and large-scale phenotyping
Helen J. Brabham, Inmaculada Hernández‐Pinzón, Chizu Yanagihara, Noriko Ishikawa, Toshiyuki Komori, Oadi Matny, Amelia Hubbard, Kamil Witek, Alexis Feist, Hironobu Numazawa, Phon Green, Antonín Dreiseitl, Naoki Takemori, Toshihiko Komari, Roger Freedman, Brian J. Steffenson, H. Peter van Esse, Matthew Moscou
Abstract
Protecting crops from diseases is vital for the sustainable agricultural systems that are needed for food security. Introducing functional resistance genes to enhance the plant immune system is highly effective for disease resistance, but identifying new immune receptors is resource intensive. We observed that functional immune receptors of the nucleotide-binding domain leucine-rich repeat (NLR) class show a signature of high expression in uninfected plants across both monocot and dicot species. Here, by exploiting this signature combined with high-throughput transformation, we generated a wheat transgenic array of 995 NLRs from diverse grass species to identify new resistance genes for wheat. Confirming this proof of concept, we identified new resistance genes against the stem rust pathogen Puccinia graminis f. sp. tritici and the leaf rust pathogen Puccinia triticina, both major threats to wheat production. This pipeline facilitates the rapid identification of candidate NLRs and provides in planta gene validation of resistance. The accelerated discovery of new NLRs from a large gene pool of diverse and non-domesticated plant species will enhance the development of disease-resistant crops.