Structural basis for size-selective perception of chitin in plants.

Structural and mechanistic insights reveal size-selective, high-affinity chitin perception in Lotus japonicus and Medicago truncatula with a hallmark bridge domain in the CHITIN PERCEPTION receptor class.

• Why it matters: Understanding how plants discriminate between different chitin oligomers is crucial for elucidating plant immune responses to microbial invasion, addressing a key gap in plant-microbe interaction knowledge.
• What they did: The study used structural analysis, biochemistry, and in planta functional studies of nanobodies to uncover the mechanism of size-selective chitin recognition and identified the CHITIN ELICITOR RECEPTOR KINASE class as low-affinity co-receptors.
• The result: Findings establish the structural basis for differential chitin perception and receptor complex assembly, advancing understanding of plant immune signaling and potential strategies for crop protection.