Phosphatidylcholines from Pieris brassicae eggs activate an immune response in Arabidopsis

• Published in: eLife Vol. 9
• Main Authors: Stahl, Elia, Brillatz, Théo, Ferreira Queiroz, Emerson, Marcourt, Laurence, Schmiesing, André, Hilfiker, Olivier, Riezman, Isabelle, Riezman, Howard, Wolfender, Jean-Luc, Reymond, Philippe
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 28.09.2020; eLife Sciences Publications, Ltd; eLife Sciences Publications Ltd
• Subjects: Animals; Arabidopsis - drug effects; Arabidopsis - immunology; Arabidopsis thaliana; Butterflies - metabolism; Cell death; Gene expression; Immune response; innate immunity; insect eggs; Larva - chemistry; Mass spectrometry; Nuclear magnetic resonance spectroscopy; Ovum - chemistry; phosphatidylcholines; Phosphatidylcholines - immunology; Phosphatidylcholines - metabolism; Phosphatidylcholines - pharmacology; Pieris brassicae; Plant Biology; plant defense; Plants (Organisms); Pieris brassicae; plant defense; innate immunity; A. thaliana; phosphatidylcholines; plant biology; insect eggs
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.60293

Recognition of conserved microbial molecules activates immune responses in plants, a process termed pattern-triggered immunity (PTI). Similarly, insect eggs trigger defenses that impede egg development or attract predators, but information on the nature of egg-associated elicitors is scarce. We performed an unbiased bioactivity-guided fractionation of eggs of the butterfly Pieris brassicae . Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry of active fractions led to the identification of phosphatidylcholines (PCs). PCs are released from insect eggs, and they induce salicylic acid and H 2 O 2 accumulation, defense gene expression and cell death in Arabidopsis , all of which constitute a hallmark of PTI. Active PCs contain primarily C16 to C18-fatty acyl chains with various levels of desaturation, suggesting a relatively broad ligand specificity of cell-surface receptor(s). The finding of PCs as egg-associated molecular patterns (EAMPs) illustrates the acute ability of plants to detect conserved immunogenic patterns from their enemies, even from seemingly passive structures such as eggs.