VIROPLANT isolated and characterized 33 new bacteriophages that are good candidates for a phage biocontrol approach for some important bacterial plant diseases, such as bacterial wilt of roses, bacterial canker of cherry and kiwi vine and crazy root diseases of cucurbits. For some of them, such as the bacterial canker of kiwi vine, the translation to a specific in vivo application still remains to be ascertained due to issues defining a correct delivery method. However, for the cherry pathogens and for the rose system, the phage cocktails are ready to approach interested companies to bring them to the market. The standardized methodology for environmental risk assessment for phage therapy tested in VIROPLANT could be further exploited by stakeholders involved in regulation (e.g. EFSA).
Regarding the use of mycovirus to limit biotrophic fungal/oomycetes diseases, the main exploitable results obtained in VIROPLANT are:
• The description of the viromes can be exploited for new theories of virus evolution by scientists.
• We have characterized more than new 1000 virus segments corresponding to circa 600 new mycovirus species. Their sequences are deposited in public repositories (GenBank) and described in peer-reviewed publications, and these could be potentially exploited for specific biocontrol applications.
• Several hypovirulent strains of B. cinerea with biocontrol potential were identified and some mycoviral candidates inducing hypovirulence were also characterized. An infectious clone of Botrytis virus F has been successfully developed and will be exploited for the construction of a viral expression and VIGS vector.
• A VIGS vector with potential to produce dsRNA to be used for RNAi approaches against fungi has been developed. The one based on CHV1 infectious clone was shown to work on endogenous silencing and can be exploited for reverse genetic approaches by other scientists.
Regarding the search of new viruses to control insect pests and vectors, VIROPLANT exploitable results are:
• A “turnkey” approach for virus identification/survey in agrosystems.
• Two new VIGS insect virus vectors.
• The development and breed of thrips populations with specific persistent virus that can interfere with tospovirus transmission (synergy or antagonism).
• For the plant mitovirus, the virus-associated resilience to abiotic stress could become a strategy for improving plant performance, i.e. breeding for resistance with mitochondrial viruses.
VIROPLANT also conducted an inquiry in the economical/regulatory landscape to accompany virus-based plant protection products (PPPs) to the market. The potential exploitable results of this analysis are:
• The results of the techno-economic system analysis can guide companies wanting to invest in virus-based PPPs and inspire funding agencies about the necessity and urgency of supporting research in this field.
• Gaps in the regulation and research to bring phage-based PPPs to the EU market have been identified and should be considered by the regulatory agencies.
• Preliminary three-tier protocol is proposed for the environmental impact of phage-based PPPs.
VIROPLANT also considered ways to monitor, and possibly improve, social acceptance of virus-based PPPs.
The results are of utmost important to policy makers and whoever is involved in technological innovation in the biotechnological field. A roadmap towards conditions to improve the “process” of acceptability is paved.
The dissemination activities implemented in the project are: 24 open access peer-reviewed scientific publications (that obtained a total of 246 citations), 4 articles published in local magazines for farmers, 25 participations to national and international scientific conferences (9 posters and 16 oral presentations), 13 seminars to academics and 16 meetings with stakeholders.
