DCL-suppressed Nicotiana benthamiana plants: Valuable tools in research and biotechnology.

RNA silencing is a universal mechanism involved in development, epigenetic modifications and responses against biotic (viruses-viroids) and abiotic stresses. The major components of this mechanism are Dicer-like (DCL), Argonaute (AGO) and RNA-dependent RNA polymerase (RDR) proteins. Understanding the role of each component is of great scientific and agronomic importance. Plants including Nicotiana benthamiana, an important plant model, have usually four DCL proteins, each of which has a specific role namely, being responsible for the production of an exclusive small RNA population. Here, we have used RNAi technology to target DCL proteins and produced single and combinatorial mutants for DCL. We analyzed the phenotype for each DCL knock-down plant together with the small RNA profile by NGS. We have also investigated transgene expression as well as viral infections and were able to show that DCL suppression results in distinct developmental defects, changes in small RNA populations, increase of transgene expression and finally higher susceptibility in certain RNA viruses. Therefore, these plants are excellent tools for i) studying the role of DCL enzymes, ii) overexpressing proteins of interest and iii) understanding the complex relationship between plant silencing mechanism and biotic or abiotic stresses. This article is protected by copyright. All rights reserved.