CleanStem

Certain viral diseases of the vine including the FanLeaf (FL) or leafroll are likely to affect the sustainability of many vineyards around the world. Some areas are literally stricken, as evidenced by the studies of the "vine decline national plan" (www.plan-deperissement-vigne.fr). In Champagne, for example, FL's disease is considered to be the main concern, and global losses of several billion euros are estimated. Alas, unlike the fungal diseases (downy mildew, powdery mildew, ...) for which resistance genes have been identified and are now exploited to fight against these diseases as a replacement for pesticides, no gene for antiviral resistance in the genetic heritage of the vine is known. It is therefore impossible to answer the problem of vine diseases by conventional genetic approaches. Global and European viticulture in particular is facing a stalemate in antiviral control. Biotechnology lab of Vine Viruses led by Christophe Ritzenthaler (CR) has recently shown that it is possible to confer antiviral resistance to grapevine fanleaf virus (GFLV), the main agent. of FL disease, using Nanobodies (Nbs) derived from immunoglobulins of camelids. On the same principle, Nbs possessing antiviral activity against other major vine viruses, including Arabis mosaic virus (ArMV), also at the origin of FL, have been isolated and characterized (CR). In addition, studies within the IBMP (CR and Pascal Genschik teams) on the search for cellular partners involved in the replication of several plant viruses have made it possible to identify proteins of the Arabidopsis DRB family possessing broad-spectrum (confidential) antiviral activity. All of this work, which opens up new prospects for the fight against FL and possibly against other vine viruses, is at the origin of the desired partnership between Mercier group (industrial partner), world leader in the viticultural nursery. , and CNRS-IBMP for the creation of the LabCom CleanStem. The purpose of CleanStem will be to pool the scientific know-how developed at IBMP (virology, genetics, etc.) in search of antiviral factors and Mercier's international expertise in vegetative propagation, transformation, grafting and commercialization of grapevine. The main purpose of this marriage of reason is twofold. The commercial purpose of CleanStem will be the creation and marketing of new varieties of elite vines resistant to viruses. In a very active international environment, this will give Mercier a major competitive advantage and thus resolve the technological stalemate in antiviral control. The scientific and academic goal of CleanStem will be to lead to the creation of an internationally recognized research center in the field of viral diseases. By doing so, it will improve the visibility and attractiveness of the IBMP as a whole and over the long term. The priority of CleanStem will be the CN virus resistance of the vine but may spread to other major diseases. To do this, CleanStem's activities will be deployed according to three axes detailed in the roadmap (§3). Axis 1 (TRL5-6) will focus on conventional biotechnological exploitation by transgenesis of Nbs. Axis 2 (TRL3-4) will be devoted to the characterization of the antiviral activity of Arabidopsis and grapevine DRBs and their so-called new generation or green biotechnology exploitation (CRISPR / Cas). Finally, the more exploratory axis 3 (TRL2-3) will be devoted to the search for new viral restriction factors directly in the vineyard, in the more distant perspective - beyond the operational phase of the LabCom - of their exploitation by classical genetics. .