Prado subjected Easter Lily (Lilium longiflorum) pollen tubes to an artificial source of NO and then, by removing the NO using a NO scavenger, saw that the re-orientation of the pollen tubes was blocked. "In animal physiology, NO is involved in intercellular communication events and in plants could be acting as a guidance cue for the pollen tube to an unfertilised ovule", Prado explains, "It could work as a safe guard mechanism to block polyspermy, i.e. dual fertilization".
Prado's research was the first to demonstrate a role of NO in pollen tube biology, and further work is being performed to confirm a function of NO in plants similar to that in animals.