CSIC-UPV improves technology to produce multiple short RNA fragments that can «turn off» genes without side effects
A team from the Institute of Molecular and Cellular Plant Biology (IBMCP), a joint center of the Spanish National Research Council (CSIC) and the Polytechnic University of Valencia (UPV), has developed a technique to obtain more effective vaccines to improve plant performance and protect them against infections.
The researchers have refined a technique to produce multiple short RNA fragments designed to turn off one or more specific genes in plants without causing side effects, as reported by UPV and CSIC. This technology uses a harmless virus as a vehicle to deliver these molecules to plants by spraying them, silencing the desired genes without the need to modify them, that is, without creating transgenic plants.
Their work is published in the journal ‘Nucleic Acids Research’. Specifically, the IBMCP team has improved the production of syn-tasiRNAs, small RNA fragments that copy DNA instructions for cells to function, designed to turn off specific genes in plants.
The use of these molecules is «limited» because long RNA versions need to be introduced into plants to produce syn-tasiRNAs. This team had already used a similar technology, which produced a single small RNA fragment, in a previous work, demonstrating its usefulness and applications.
In the study now published, they demonstrate that it is possible to generate several effective syn-tasiRNAs using much «shorter and simpler» RNA versions. By introducing these minimal versions into model plants such as Arabidopsis thaliana and Nicotiana benthamiana, they produced very effective syn-tasiRNAs, capable of turning off not one, but several genes at the same time.
«We have managed to produce several very effective syn-tasiRNAs from minimal precursor sizes that turn off one or several genes of the plant with great efficiency and specificity without causing side effects,» said Alberto Carbonell, a CSIC researcher leading the work.
BLOCK THE INFECTION WITH A SINGLE SPRAY
Additionally, they verified that these minimal versions work when introduced into the plant using a virus, without the need to genetically modify it. «We applied these syn-tasiRNA molecules in spray mode using a harmless virus as a vehicle, and achieved widespread and long-lasting silencing of certain genes in plants without the need to produce transgenic plants,» Carbonell stated.
This technique is called syn-tasiR-VIGS. They used it to ‘vaccinate’ plants against a harmful virus, completely protecting them. «We have effectively vaccinated plants against the tomato yellow leaf curl virus with a single spray, completely blocking the infection and demonstrating its potential as a scalable and non-transgenic antiviral platform,» said the CSIC scientist at IBMCP. The technique is in the process of being patented at the European level.
IMPROVING AND PROTECTING WITHOUT TRANSGENICS
This new technology has advantages such as greater precision and safety (producing molecules that act specifically without causing unwanted effects); there is no need to modify the plant’s DNA to produce syn-tasiRNAs and turn off desired genes; reducing the size of precursor molecules facilitates their preparation and lowers costs; syn-tasiRNAs against various genes or even different viruses could be included in a single application, a ‘multivirus’ vaccine; and it has less environmental and regulatory impact, as it does not genetically modify the plant or use dangerous viruses.
«This type of treatment could be applied in crops to selectively turn off certain plant genes,» Carbonell described. «This would allow, for example, to improve their performance, make them more resistant to environmental stress, such as drought or heat, or facilitate their study in the laboratory. It would also serve to protect plants against pathogens such as viruses or fungi. In this case, it would function as a new generation of plant vaccines: an extract with a harmless virus would be applied, causing the plant to produce effective and specific syn-tasiRNAs capable of blocking the pathogen and thus preventing infection,» the researcher stated.