Fast-Forward Identification of Highly Effective Artificial Small RNAs Against Different Tomato spotted wilt virus Isolates.

Artificial small RNAs (sRNAs), including artificial microRNAs (amiRNAs) and synthetic trans-acting small interfering RNAs (syn-tasiRNAs), are used to silence viral RNAs and confer antiviral resistance in plants. Here, the combined use of recent high-throughput methods for generating artificial sRNA constructs and the Tomato spotted wilt virus (TSWV)-Nicotiana benthamiana pathosystem allowed for the simple and rapid identification of amiRNAs with high anti-TSWV activity. A comparative analysis between the most effective amiRNA construct and a syn-tasiRNA construct including the four most effective amiRNA sequences showed that both were highly effective against two different TSWV isolates. These results highlight the usefulness of this high-throughput methodology for the fast-forward identification of artificial sRNAs with high antiviral activity prior to time-consuming generation of stably transformed plants.