Hailing Jin studies molecular mechanisms of plant-pathogen interactions, with an overall goal to develop effective and environmentally friendly strategies to control plant diseases and to ensure sufficient food production. One of her research focuses is cross-kingdom RNA interference and small RNA trafficking between plant and fungal pathogens. She has demonstrated that some small RNAs from eukaryotic pathogens can be transported into host plant cells and suppress host immunity genes for successful infection. Jin has also discovered that such cross-kingdom genetic interference is bi-directional: plant hosts can send small RNAs into pathogens to silence fungal virulence genes as part of its immune response. Furthermore, her research group has discovered that many fungal pathogens can take up double-stranded RNAs and small RNAs from the environment. She has been able to significantly inhibit grey mold disease caused by Botrytis cinereaby by applying small RNAs or double-stranded RNAs that target Dicer genes of B. cinerea on the surface of fruits, vegetables and flowers. Such pathogen gene-targeting RNAs represent a new generation of fungicides that are durable and eco-friendly.