Domain-less defenders: evolutionary innovations and agricultural promise of noncanonical NLRs

Noncanonical nucleotide-binding leucine-rich repeat (NLR) genes, which lack typical N-terminal domains, are abundant in plants but their functions remain poorly understood. Two recent studies have cloned members of this family and offer clues into the role of this family in plant immunity. Independently, these workers cloned two noncanonical NLR genes, RMES1A and RMES1B, that confer resistance to the aphid Melanaphis sorghi in sorghum (Sorghum bicolor). Furthermore, their cognate insect effector MsEF1, a phosphatase-like protein, was identified. These studies establish that NLRs lacking clear functional domains can mediate insect resistance and provide a new genetic resource for engineering pest-resilient crops.