Plenary Presentation Title: Cross-kingdom RNA communication and nanotechnology enabled spray induced gene silencing for crop protection

Cross-kingdom RNA communication and nanotechnology enabled spray induced gene silencing for crop protection

Small RNAs (sRNAs) are short non-coding RNAs that mediate gene silencing in a sequence-specific manner. We discovered that many aggressive fungal pathogens can take up RNAs from the environment (Wang et al., Nature Plants 2016; Qiao et al., Plant Biotech. J. 2021), which made it possible to use fungal gene-targeting double-stranded RNAs or small RNAs to silence fungal virulence-related genes and control fungal diseases. However, spray-induced gene silencing (SIGS) is limited by the unstable nature of RNA under environmental conditions. We have shown that plants and fungi utilize extracellular vesicles to protect and deliver RNAs into interacting organisms in nature, a phenomenon known as cross-kingdom RNA trafficking (Cai et al., Science 2018; He et al., Nature Plants 2021,Nature Communications, 2023) . Inspired by the natural mechanism of extracellular vesicle-mediated cross-kingdom RNA trafficking across all domains of life and the use of liposomes in COVID vaccines, we developed artificial vesicles and plant-derived nanovesicles for RNA encapsulation to control fungal pathogens (Qiao et al., Plant Biotech. J. 2023; Niño-Sánchez et al., JIPB 2022). These nanotechnologies largely enhance RNA stability on plants, allowing the fungal gene-targeting RNAs to be effective for crop protection for weeks as an eco-friendly alternative to chemical fungicides. Furthermore, we recently discovered cross-kingdom RNA trafficking between bacteria and fungi, which allows us to employ beneficial bacteria to continuously produce and deliver antifungal dsRNA for plant protection.