Sir

The Nobel prize, by recognizing the individuals behind breakthroughs, inspires all scientists to do great science. The discovery of RNA interference (RNAi) changed the face of gene regulation, a feat deservedly recognized with this year's Nobel Prize in Physiology or Medicine1.

As undergraduates, we witnessed with great excitement the discovery of gene silencing. At that time, almost all research in that area was being conducted by plant scientists, and as young plant biologists we were lucky to have front-row seats to this molecular drama.

Like all great advances, RNAi is turning out to be important in ways that could not have been guessed at even a decade ago. Therefore we were not surprised to discover that the topic was selected for this year's honour — but we were shocked that the plant scientists who were so crucial in discovering and communicating the underlying mechanism of RNAi were not awarded a share.

Of course there is often controversy around the awarding of the Nobel prize. Yet in this case we feel that a grave error has been made in overlooking key researchers, all of whom work on plants. Most of the six points cited in support of the prize were not first shown by Andrew Fire or Craig Mello, who won the prize, but were already known from plant research. For example, the sequence specificity, RNA degradation and post-transcriptional nature of gene silencing had all been shown in studies on plants and plant viruses2,3. In addition, the observation that silencing is non-cell-autonomous was first done in plants4. Moreover, the models involving double-stranded RNA and amplification mechanisms had been proposed by plant researchers before the publications of RNAi mechanisms in animal systems5.

In our view, the main importance of the work by Fire, Mello and colleagues (accessible via ref. 1., together with other relevant articles) was the integration of these elements to demonstrate that they stood up to testing in an animal system, the nematode worm Caenorhabditis elegans. Subsequently, plant research continued to break new ground on mechanisms of RNAi-based genetic regulation.

As the Nobel prize may be shared by three people, a plant scientist should have been included. One who springs to mind as a pioneer in the field is David Baulcombe (see http://www.sainsbury-laboratory.ac.uk/dcb). His work was key to understanding the mechanism of RNAi and paved the way for Fire and Mello's findings.

By ignoring the work done in plants, the Nobel committee has undermined the values at the centre of the prize and is sending a discouraging message, especially to young researchers.