NBS-LRR proteins are a large family of disease resistance genes in plants, characterized by nucleotide-binding (NBS) and leucine-rich repeat (LRR) domains. These proteins play a critical role in detecting pathogens, including bacteria, viruses, fungi, nematodes, insects, and oomycetes. They are divided into two subfamilies: TIR-domain-containing (TNL) and CC-domain-containing (CNL). While both subfamilies are involved in pathogen recognition, they differ in sequence and signaling pathways. NBS-LRR proteins are abundant in plant genomes and have undergone extensive duplication and diversification, leading to a wide variety of variants. The NBS domain is involved in signaling and ATP binding, while the LRR domain is involved in protein-protein interactions and ligand binding. The carboxy-terminal domains vary in size and composition between TNL and CNL proteins. NBS-LRR proteins are involved in plant defense responses, including the hypersensitive response and activation of defense-related genes. They are also involved in the regulation of gene expression and signaling pathways. The function of NBS-LRR proteins is still not fully understood, but they are thought to monitor the status of plant proteins targeted by pathogen effectors. Recent studies have shown that NBS-LRR proteins can act as adaptors or regulators of other disease resistance proteins. The evolution of NBS-LRR proteins is influenced by various genetic mechanisms, including gene duplication, unequal crossing-over, and sequence exchange. The role of NBS-LRR proteins in plant immunity is an active area of research, with ongoing efforts to understand their structure, function, and regulation.NBS-LRR proteins are a large family of disease resistance genes in plants, characterized by nucleotide-binding (NBS) and leucine-rich repeat (LRR) domains. These proteins play a critical role in detecting pathogens, including bacteria, viruses, fungi, nematodes, insects, and oomycetes. They are divided into two subfamilies: TIR-domain-containing (TNL) and CC-domain-containing (CNL). While both subfamilies are involved in pathogen recognition, they differ in sequence and signaling pathways. NBS-LRR proteins are abundant in plant genomes and have undergone extensive duplication and diversification, leading to a wide variety of variants. The NBS domain is involved in signaling and ATP binding, while the LRR domain is involved in protein-protein interactions and ligand binding. The carboxy-terminal domains vary in size and composition between TNL and CNL proteins. NBS-LRR proteins are involved in plant defense responses, including the hypersensitive response and activation of defense-related genes. They are also involved in the regulation of gene expression and signaling pathways. The function of NBS-LRR proteins is still not fully understood, but they are thought to monitor the status of plant proteins targeted by pathogen effectors. Recent studies have shown that NBS-LRR proteins can act as adaptors or regulators of other disease resistance proteins. The evolution of NBS-LRR proteins is influenced by various genetic mechanisms, including gene duplication, unequal crossing-over, and sequence exchange. The role of NBS-LRR proteins in plant immunity is an active area of research, with ongoing efforts to understand their structure, function, and regulation.