Researchers from Consejo Superior de Investigaciones Cient?­ficas-Universitat Polit?¨cnica de Val?¨ncia in Spain have developed two techniques based on trans-acting small interfering RNAs (syn-tasiRNAs) to moderate the degree of silencing induced by a plant's genes. The findings are released in Nucleic Acids Research.

RNA interference (RNAi) is commonly used in plants to silence genes and study gene functions or improve crops. However, methods for fine-tuning the degree of induced silencing are missing. Thus, Lucio L??pez-Dolz and the team came up with two techniques based on artificial small RNAs (sRNAs) to fine-tune RNAi efficacy in plants.

The first method entails modification of the precursor position from which the syn-tasiRNA is expressed. Using this method, it was shown that the accumulation and efficacy of Arabidopsis TAS1c-based syn-tasiRNAs progressively decreased as the syn-tasiRNA is expressed from positions more distal to the trigger miR173 target site. The second method tweaks the degree of base-pairing between the 3â?? end of the syn-tasiRNA and the 5â?? end of the target RNA.

Both methods have been successfully applied in Arabidopsis thaliana and Nicotiana benthamiana.

[academic.oup.com]