PubMed · 2026-04-16
Plants use tiny molecular signals called small RNAs to coordinate defenses across their entire body and even fire them like weapons into attacking fungi and other pathogens. Researchers are now harnessing this natural system to develop spray-on RNA treatments that could replace or reduce chemical pesticides in farming.
Small RNAs travel long distances through plant tissue via plasmodesmata and the phloem, enabling whole-plant immune coordination rather than only local cell-level responses.
Cross-kingdom RNA interference (ckRNAi) allows plant-derived RNAs to silence genes inside fungal and oomycete pathogens, forming the basis of two crop-protection strategies: Host-Induced Gene Silencing (HIGS) and Spray-Induced Gene Silencing (SIGS).
Key delivery challenges — including environmental RNA degradation and inconsistent uptake by different pathogens — are being addressed through nanocarriers, synthetic biology, and machine-learning design tools.