Short RNAs in tomato

Short RNAs are 20-24 nucleotide long non-coding RNA molecules generated by one of the Dicer-like enzymes. They recognize specific RNA or DNA sequences and guide the RNA silencing complex to their targets leading to post-transcriptional or transcriptional gene silencing of the target. Most of our knowledge about short RNAs comes from studying the model species Arabidopsis. Recently, however, several reports emerged about short RNAs in tomato, which is a model plant for fleshy fruit development and ripening. Tomato short RNAs have been sequenced and a database was established. Novel non-conserved microRNAs were found that showed differential expression between fruit and other tissues, even during fruit development, suggesting that they may play a role in fruit formation. Several target genes were predicted and validated for both conserved and non-conserved miRNAs and some of these targets are key players in fruit ripening, such as Colourless non-ripening. The present study reviews the current state of tomato short RNAs research and suggests future directions.