Natural peptide strengthens litchi defenses against postharvest downy blight

Researchers have identified a natural peptide derived from litchi, known as LcPIP1, capable of increasing fruit resistance against litchi downy blight, a postharvest disease caused by Peronophythora litchii that leads to significant yield losses and quality deterioration.

The study shows that synthetic application of LcPIP1 significantly enhances the fruit's defensive capacity by activating several physiological and biochemical mechanisms associated with plant immunity.

Researchers observed increased accumulation of ATP, anthocyanins and lignin, compounds linked to improved resistance against pathogen infection.

The treatment also stimulated immune responses by increasing cytosolic calcium levels and reactive oxygen species accumulation while activating mitogen-activated protein kinase (MAPK) signaling pathways.

The work identified the transcription factor LcWRKY34 as a key regulator responsible for activating the precursor gene LcprePIP1 and enhancing induced disease resistance.

Transcriptomic and metabolomic analyses revealed that LcPIP1 regulates defense-related gene expression and promotes the accumulation of protective metabolites.

According to the authors, this is the first evidence demonstrating the role of this peptide in activating defense responses in litchi fruit, opening new opportunities for biological postharvest disease management strategies.

Source

Ye, X., Zhang, S., Wang, Y., Ren, Y., Xu, X., Jiang, Y., & Li, T. (2026). Pathogen-Associated Molecular Pattern (PAMP)-Induced Peptide LcPIP1 Derived from Litchi Promotes the Resistance of Litchi Fruit against Litchi Downy Blight Caused by Peronophythora litchii. Journal of Agricultural and Food Chemistry. American Chemical Society.