Molecular basis of nematode-associated molecular pattern (NAMP)-triggered immunity in potato

About This Grant

Plant parasitic nematodes cause an estimated US$80 to 157 billion in annual crop losses worldwide. The most economically important plant parasitic nematodes include root-knot nematodes from the genus Meloidogyne and cyst nematodes of the genera Heterodera and Globodera. Both root-knot nematodes and cyst nematodes, as sedentary endoparasites, penetrate the host root to establish a feeding site (a giant cell or syncytium), where they settle down and feed through subsequent sedentary life stages. Plants in turn use a sophisticated innate immune system to perceive and defend themselves against the invading nematodes. This project aims to address a key question related to plant resistance to nematodes: how do plants detect nematode-derived small-molecule signals, specifically ascaroside 18 (Ascr18), to activate their immune system and fight infection. Besides elucidating the mechanisms underlying potato resistance to the notorious potato cyst nematode Globodera pallida, this project will also support the training of high school, undergraduate and graduate students. By connecting cutting-edge molecular biology with real life agriculture problems, this project will motivate and engage students in plant biology research and inspire them to become the next generation of leading plant scientists. Plants have evolved pattern recognition receptors (PRRs), which detect pathogen-associated molecular patterns (PAMPs) as a basal layer of immune response to activate pattern-triggered immunity (PTI) against invading pathogens and pests. Extensive studies over the past two decades have identified numerous PAMP-PRR-mediated PTI signaling pathways against numerous types of pathogens. However, the molecular basis underlying the activation and signaling of PTI in plant-nematode interactions is largely unknown. It has been recently found that the potato (Solanum tuberosum) PRR, Nematode-Induced Leucine-Rich Repeat Receptor-Like Kinase 1 (StNILR1), recognizes the nematode-associated molecular pattern (NAMP) ascaroside 18 (Ascr18), thereby conferring resistance to cyst nematode Globodera pallida. In addition to canonical PTI signaling, StNILR1 and its coreceptor Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 (BAK1) modulate RNA metabolism machinery to down-regulate genes essential for the development of nematode feeding site (syncytium), thereby interfering with nematode parasitism. This project will leverage these preliminary findings to elucidate the molecular basis underlying Ascr18-triggered immune signaling in potato. Specifically, the project will elucidate the mechanistic basis of Ascr18-StNILR1/StBAK1-mediated immunity, determine the role of the StCAF1 deadenlyase in potato PTI responses, and dissect the transcriptome reprogramming caused by Ascr18. The project has implications for U.S. agriculture through improving potato production and enables workforce development through training of high school, undergraduate and graduate students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.