Structure and Functions of NDR1/HIN1-Like (NHL) Proteins in Plant Development and Response to Environmental Stresses.

The NON-RACE-SPECIFIC DISEASE RESISTANCE 1/harpin-induced 1-LIKE (NHL) gene family plays pivotal roles, including pathogen resistance, abiotic stress tolerance, and developmental regulation, underscoring their functional versatility in developmental and physiological processes of plants. NHL proteins often localize to the plasma membrane and contain conserved motifs, including the LEA2 and transmembrane domains, enabling dynamic interactions with signalling molecules and transcription factors. The ability of NHL proteins to dimerize and oligomerize further enhances their regulatory potential in signalling pathways. This review explores the structural and functional diversity of NHL proteins including their localizations, interacting proteins, and responses to abiotic and biotic stresses, ion transportation, seed germination, and responses to phytohormones. Future research integrating phylogenetics, and advanced tools including artificial intelligence will unlock the full potential of this gene family for breeding climate-resilient crops and agricultural sustainability.