Small RNA Profiles from Virus-Infected Fresh Market Vegetables

Functional small RNAs, such as short
interfering RNAs (siRNAs)
and microRNAs (miRNAs), exist in freshly consumed fruits and vegetables.
These siRNAs can be derived either from endogenous sequences or from
viruses that infect them. Symptomatic tomatoes, watermelons, zucchini,
and onions were purchased from grocery stores and investigated by
small RNA sequencing. By aligning the obtained small RNA sequences
to sequences of known viruses, four different viruses were identified
as infecting these fruits and vegetables. Many of these virally derived
small RNAs along with endogenous small RNAs were found to be highly
complementary to human genes. However, the established history of
safe consumption of these vegetables suggests that this sequence homology
has little biological relevance. By extension, these results provide
evidence for the safe use by humans and animals of genetically engineered
crops using RNA-based suppression technologies, especially vegetable
crops with virus resistance conferred by expression of siRNAs or miRNAs
derived from viral sequences.