A wheat lncRNA-encoded peptide promotes antiviral resistance by targeting viral NIb for autophagic degradation.

Long noncoding RNAs (lncRNAs) are increasingly recognized as sources of functional peptides that regulate plant development and immunity, yet little is known about whether lncRNA-encoded peptides participate in antiviral defense. Through transcriptomic analysis combined with peptide-coding potential prediction, we identified wheat lncRNA19864, which is highly expressed in wheat yellow mosaic virus (WYMV)-resistant cultivars and encodes a 39-amino-acid peptide, TaLEP1. Genetic manipulation of TaLEP1 expression revealed that TaLEP1 acts as a positive regulator of wheat resistance to WYMV. Mechanistically, TaLEP1 forms oligomers and interacts with both the host autophagy factor TaATG18a and the viral replicase NIb, thereby facilitating NIb recruitment to autophagosomes for degradation. Disruption of TaLEP1 oligomerization or TaATG18a function impaired NIb degradation and compromised TaLEP1-mediated antiviral resistance. Notably, TaLEP1 also confers resistance to other Potyviridae members, including turnip mosaic virus and soybean mosaic virus, by similarly targeting their NIb proteins for degradation. These findings demonstrate that an lncRNA-encoded peptide is involved in plant antiviral immunity and offer a potential strategy for engineering broad-spectrum virus resistance in crops.