25 years of Protist: A thank you to Editor-in-Chief Michael Melkonian

The proteins containing the lysin motif (LysM) are involved in the host-pathogen interaction, known as a kind of carbohydrate-binding protein. Plant LysM proteins largely act as pattern recognition receptors (PRRs) that recognize chitin to stimulate the immunity of the plant. Contrastingly, fungal LysM prevents chitin sensing or signaling to decrease the host immunity induced by chitin. The plant-specific LysM receptor-like kinases (LysM-RLKs) can modulate the formation of arbuscular mycorrhizal (AM) and rhizobium-legume (RL) symbiosis in response to the chemical signals generated by the symbiotic partners, i.e., fungal and bacterial, respectively. While the studies on LysM-RLKs are majorly done in legume species, some interesting studies in non-leguminous species have also been done that highlight their involvement in regulating symbiosis. LysM-RLKs are crucial sensors of biotic stresses and induce plant immune response, where the study of their structure and precise function provides a fuller understanding of the processes controlling the plant-pathogen interactions. In the present chapter, we have analyzed the structure and function of LysM-RLKs to explain their role in the regulation of the plant’s immune response generated by various pathogens.