Genetic dissection of  NLP-triggered immunity in Arabidopsis
T. RAAYMAKERS (1), R. Hijne (1), T. Van Butselaar (1), G. Van den Ackerveken (1) (1) Utrecht University, Netherlands

Necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are secreted by a wide range of plant-associated microorganisms. Previously, we showed that both cytotoxic and non-cytotoxic NLPs act as a microbe-associated molecular pattern (MAMP) in Arabidopsis. Specifically, a 24 amino acid fragment, nlp24, derived from a conserved region of fungal, bacterial and oomycete type 1 NLPs triggers defense. The widespread distribution of NLPs makes this family the first proteinaceous MAMP identified in three different kingdoms of life. A receptor complex consisting of RLP23–SOBIR1–BAK1 mediates NLP-triggered immunity (NTI) in Arabidopsis. Furthermore, transgenic potato plants expressing RLP23 showed increased resistance to oomycete and fungal pathogens. Here, we present our data on the genetic dissection of NTI, using a transgenic Arabidopsis line expressing the non-cytotoxic HaNLP3 gene from an estradiol-responsive promoter. When treated with estradiol plants become severely stunted and plant immunity is strongly activated. M2 seeds of an EMS-mutagenized population were screened for loss of NLP-triggered growth inhibition. We selected ~40 mutants showing normal growth after estradiol treatment and insensitivity to the nlp24 peptide. The obtained decreased NTI (dni) mutants are analysed for defects in responsiveness to other MAMPs and their susceptibility to pathogen infection. We will report on our progress on dni mutant analysis and cloning of the corresponding DNI genes.

Abstract Number: P17-590
Session Type: Poster